My 1978 3.0 L head stud replacement thread
 

I'll start a fresh thread for documenting my head stud replacement. The reason for pulling the engine was one broken exhaust stud (#3 exhaust side). My plan is to replace all exhaust side studs with the factory 993 studs. I'll also be installing oil-fed tensioners along the way. Clutch will be checked. I have no history on the clutch, so I have no idea of its condition. I do not intend to undertake a valve job at this time, but we'll see how things go.

Here's my getting started post reproduced from my engine drop announcement thread:

The engine drop went well. I do have a lift, a Bend Pak low-rise lift (LR60P). Turns out this lift is not high enough to remove the engine without bumper removal. I was kind of bummed about that. I think we had about 31-32 inches of clearance under the bumper with the lift at max height. I just measured height of the engine plus jack platform with the ATV jack all the way down. It's at 34 inches to the high point, the top of the CIS intake boot. Next time, I'll get the mid-rise.

Only issues were the clutch helper spring arm wouldn't come off the clutch fork shaft like it should, even with a little pry bar persuasion so we just left it on for now. And, there were a couple of snags, literally. The drivers side CV joint, which was hanging loose, caught on the throttle cable linkage rod as we were lifting the car off the engine, which was resting on the platform on the ATV jack. It bent the linkage rod nicely, but it's probably salvageable. For the record, 101 projects did say to remove this linkage. Then, a free end of one of the oil lines to the thremostat caught on the AC compressor mounting platform causing the engine/transmission to tilt forward off the platform. At first, I thought that maybe we didn't have the platform far enough under the engine/transmission (We positioned it just under the engine with the transmission unsupported.) and the weight of the transmission was causing the whole assembly to tip off the platform, but no, it was the oil line pulling the front of the engine up with the body as the lift went up. I might just replace that oil line since the tug that it got was in the direction of pulling the soft part of the hose directly out of the crimp to the hard section. I'd hate to have a weakened crimp lead to a bursting oil hose. And, oh yeah, there's a ground strap from the transmission to the body that I missed. It tore cleanly.

I'm grateful to Ed and Ed for their assistance. Of anyone who could have shown up, I probably got the two most experienced pair of hands. Many thanks.

I'm glad someone took a couple pictures during the process, because I took none. Ed and Ed were kind of on a schedule, so we kept busy.

A couple pics after the fact.

Proof that it's out
http://i51.tinypic.com/sb2cuw.jpg

I have just removed the muffler and cat, most of the engine tin, and the heater blower and heater hoses. The muffler and cat came off well. I expected more trouble with rusted bolts. I sprayed penetrant a couple days before, and all broke loose fine except one. Fortunately, it didn't round off, but rather, the bolt broke cleanly and was able to be removed without issue.

http://i51.tinypic.com/f4o64k.jpg

http://i56.tinypic.com/vsgh21.jpg

http://i56.tinypic.com/r26iit.jpg

The broken stud story in pics. This is an image of the flywheel side of the engine showing cylinder #3. (Engine tin normally covers this area.) Notice the missing stud barrel nut on the exhaust (bottom) side.
http://i53.tinypic.com/2sbnwwz.jpg

http://i55.tinypic.com/smxd2o.jpg

http://i53.tinypic.com/2en18ya.jpg

Normally, this part of #3 is covered by engine tin. In the above pic, it looks like the stud should fall out without having to remove the valve cover, but the engine tin closes up the area. Here's a pic of the tin still in place.
http://i56.tinypic.com/2hzl300.jpg

Brett

Edit: I've attached the same pics at the bottom with Rennlist's attachment feature. That way they will stick around in perpetuity. The above pics are on tinypic.com and won't last.

I spent last night putting the driver's side CV joint back together and wondering if I did it right. The joint came apart when the throttle linkage caught on it. When I saw ball bearings in the bottom of the bag, my heart sank. I thought I recall reading there is a right and wrong configuration. I need to read some more or maybe someone can educate me. I can seem to rotate the CV joint in all directions just like the other one that did not come apart, so I think it's OK. What a frickin' mess, though. I rebuilt the half shafts myself a few years ago. I was better able to control the grease then, when the joint was together. This time, putting balls back into a greased joint while it's on the shaft is a ridiculous task. And I'll probably need to replace the gaskets on both sides of the joints when everything is going back together, which means pulling the joints off the shafts... Not looking forward to that at all. I'm getting pissed about the task just thinking about it. LOL

I've got some pics of intake removal to post this evening.

Brett

Here are pics of intake and CIS fuel injection removal. It’s all pretty straightforward but fidgety because some of the nuts are difficult to reach. Get your U-joint socket adapter out. 12 nuts hold the intake tubes to the cylinder heads. I didn’t bother to look up torque specs, but I broke all but one loose with just a 1/4 in drive socket.
http://i56.tinypic.com/6hl4ex.jpg
The breather hose is in the way of access to the inner #6 nut. The hose was hardened, and I couldn’t pull it off the breather cover, so it got cut.
http://i56.tinypic.com/28srp82.jpg
The inner nut of #5 is blocked by the auxiliary air regulator (often called AAR on the discussion forums). Note the separate part not to be confused with the AAR, the auxiliary air valve (AAV), which I have pointed out. Some people may be more handy with bent wrenches to allow access to this nut, but I removed the AAR to allow me to reach it.
http://i56.tinypic.com/2hfjl3b.jpg
First remove the electrical connector. Here is a detailed description of doing so. I had difficulty the first time I tried to remove one of these on my warm up regulator and broke part of the connector, so hopefully, this will save someone else from the same trouble. First pic is of the retaining wire clip. It wraps around 3 sides of the connector.
http://i53.tinypic.com/4r8gu8.jpg
I don’t know if there is a trick to these things, but I pull up one side of the wire clip with a pick tool. When you get it into the position in the below pic, the opposite side also shifts enough so that the wire clip is clear of the retaining tangs on either side, and you can pull the connector off.
http://i56.tinypic.com/2wpq8i0.jpg
Then you put the wire back in place. The wire snaps over the retainers when you slide the connector back on. The AAR comes off with two allen bolts, and access is easy to the #5 nut.
Here’s a pic through the AAR air passage. Of course, it’s open now since it’s cold. When the AAR warms up with the engine, this passage closes down, and the idle drops to normal.
http://i51.tinypic.com/do9fzn.jpg

continued in next post

Then it’s just a matter of finding all the electrical connections and disconnecting them. There aren’t that many. (Edit: Mystery connector is the fuel pump cut-off switch.)
http://i53.tinypic.com/2u73cy1.jpg
Warm up regulator (often abbreviated WUR)
http://i54.tinypic.com/beuc5u.jpg
There are a couple others. One to the distributor, oil pressure sensors front and rear, and temp sensors on each timing chain cover, heater blower, thermo-time valve (I think it’s called). Then the intake and CIS system comes off as a unit with a little tugging here and there, and goes on the shelf to await refreshening of vacuum hoses and what-not during reassembly.
http://i53.tinypic.com/2mfzvvl.jpg
Here’s the typical breather hose oil leak.
http://i54.tinypic.com/2vl8q4y.jpg
And, here are some images of grime in the intake of the cylinder heads. I assume this is normal. If not someone can school me on it. All 6 intakes were pretty uniform in appearance, and all showed about the same amount of carbon build up on the backside of the intake valves. That’s probably a good sign. The engine ran great when it was parked a 3 years ago.
http://i55.tinypic.com/bed4qt.jpg
http://i51.tinypic.com/14uur9l.jpg
http://i56.tinypic.com/34xp8qw.jpg

BTW, feel free to comment or provide information in this thread. I know iceman didn't want to clutter things, but on the other hand, useful stuff could get lost in a separate thread.

Brett

Brett, great thread man!

I have just finished removing all of the ancillary parts off of my '85s engine. I will take a picture of the intake port and valve back-side over the weekend for comparison purposes. I have not look to closely yet, but I think in might have a fairly similar appearance.

This might be a good time to consider changing the injector o-rings. Those sleeves are a biotch to get out of the intakes, and if they leak, you'd have a hard time changing them with the engine in the car. It's possible, but very difficult.

Yes, on the list of CIS refreshing things to do. O-rings and sleeves.

Brett

Great thread, just in time. I am about to takle 2 broken headstuds in my '81...

I will be following this with great interest!

Brett, here is what my intake ports looked like. Pete went on to tell me to use lacquer thinner. Take the valve to the top where it is good and seated and start wiping it around the port with something soft like a q-tip.

https://rennlist.com/forums/5331741-post45.html

Good luck. I don't know how quickly I'll be moving. If you start soon, you could pass me up.

Brett

Thanks for the tip from Pete. About what I figured I'd be doing, if I don't send the cylinder heads out for a valve job. I already confirmed that a simple wipe with solvent will take off the grime.

I was pleased to find all 6 intakes looked almost identical.

Brett

So this is why you're taking the engine out....

Looks like 50% fun and 50% #$@$#@%$@!

This is how my intakes look. Unfortunately the dim light in the garage meant I was unable to get the camera to focus on the back side of the valve. The black coloring on the back side of the valve is pretty smooth, completely dry and "hard". I don't think I will try any cleaning at this point (I don't see much upside for the small risk involved).

Does your camera have a macro setting? Should help for the close up stuff.

Are you taking your engine apart or just freshening the outside? I saw your latest pics. It's quite clean especially under the shroud around the breather area. Did you clean it already or was it just well sealed?

You'll probably be back together and running long before me. Even with all your replating.

Brett

My (cheap) camera does have a macro setting, and that is what I was using. The trouble was, the light was bad (it was night) and I could not pick up enough light on the valve for the autofocus. I will try again, using a worklight and then things should be better.

That picture on the other thread is after an intial quick clean up. I did have some of the typical oil breather gunge, but not too bad relative to what I've seen in other pics. I think the engine is still fairly well sealed, but I will re-fresh all of those items.

I am not taking the engine itself apart. I do not have any valve guide wear symptoms, the mileage is not that high (just over 100K) and very good leakdown and compression. So, I will do a thorough freshening of the external systems and plug it back in. There was a part of me that wanted to go all the way, but I also have a 75% finished way over-restored 944S (where I did a full rebuild on the motor) project languishing! I need to get at least one car on the road in this decade!!

Removed the front engine mount, fan/alternator, engine harness, and shroud. There's nothing worth saying about the process. It's well-documented elsewhere. Just a few pics to show. I was pretty pleased with the general cleanliness of the top side with the exception of the reach of the breather leak.

One pic of the whole of the breather cover oil leak. Lots of caked gunk, but the borders are well defined. It looks chunky where I started to scrape at the gunk with a screwdriver as I debated just when and how to do the cleaning in a manner that would avoid crap dropping into the case. I don't intend to split the case, so I want it to stay clean in there. My thinking is to clean it while inverted on the engine stand. The gunk can drip straight off into a drip pan.

Next, a couple areas where there is caked material on the cylinder head fins of the middle cylinders of either side (#'s 2 and 4). The symmetry struck me. I doubt it means anything.

And, finally the engine shroud color. It's green resin fiberglass which I believe is characteristic of the 2.7 cars but painted red. The red has rubbed off in a few places showing the green through. I don't know the history of engine shroud colors, but I assume the red is original for the SC model. It's all probably laid out in the 911 books that I've had good intention to read for several years now.

Looks like no big surprises, which is good.

The only comment I'll make, as i left too early to help much, is that you should always lower the motor only an inche or two at a time-put eyes all around it to make sure nothing is pulling, caught, pinched, etc- repeat. Invariably, a wire can be forgotten or something caught on a 1/2 shaft-whatever. This applies to installation as well.

If you need any special tools, give me a holler.

If you do not send the heads out to have the valves done, you can check for leakage by pouring low viscous fluid into the port and look for weeping around the valve contact area. I use gasoline but I read that it is not a good idea. If it stays dry, you have a good seal. If the seal leaks, lightly tap (brass hammer) the stem top of the valve to bounce the head in the seat. That should release any debris or compress a small carbon partial. If there is a light weeping, you can do a light compound lapping and also have the guide clearance checked while the valve is out. If fluid pours out that is a different matter. If you do lap a valve, there is a tool that has an adjustable ball that measures the ID of guide hole size. The difference between that and your valve stem size will tell you if you are within spec.

The 2 tools are not that costly and are good to have around.

Harbor Freight and I think Pep Boys sell huge jack stands that are high enough to drop the engine to the ground. I have used the PepBoys on the P car and the Harbor with the tractor but not on the 911.

Thanks for the tips. I probably should test the valves for leakage rather than decide blindly not to do anything with them.

Brett

Yeah, it is cheap, quick, and easy.

My Brother is a Mech and does exactly what jake does as a quick check to see if it needs valve work.

Let's keep race, religion and sexual bias out of the conversation here.

No, I'm thinking Brother Mech can say a little prayer that my valves will be fine, and I can be spared the demonic cost of a valve job. That can't be a bad thing. lol

Brett

ED------------- “Let's keep race, religion and sexual bias out of the conversation here.”

But, but, but, Ed, although:

1. P cars are only a cult and not a religion; many find religion when strange sounds rumble from the engine bay.
2. Race/racing is definitely a valid subject.
3. If a Porsche aint sexy, then we are all lost. OH, uh, missed the word BIAS. I am not sure we can go there, automatics are a touchy subject.

exhaust off
 

The exhaust is now off. I don't know what you guys are talking about. A little penetrant, and my exhaust nuts came off like butter (well, one backed out the stud, but no matter). Maybe it's that this 911 has been in Las Vegas or San Diego all its life. :) I had the MAPP gas at the ready and swear words on the tip of my tongue, but neither was needed.

5 of the exhaust ports looked similar, but the residue coating #4 was much whiter. I thought that was interesting, but I don't know what it means, if anything. I know I said all the intake ports looked similar, but one of them had a little oil pooled against the intake valve when I looked closer. It may have been #4.

Exhaust port of #5 (The rods projecting into the exhaust ports are the air injection ports, a feature of 1978 and 1979.)
http://i51.tinypic.com/10sc21d.jpg

Exhaust port of #4
http://i54.tinypic.com/bg1n5.jpg

I also realized this evening that one cylinder head, #5, is different than the others. The intake side of #5 has more "missing" fins.
http://i51.tinypic.com/14y69l0.jpg

And what I assume is a production date stamp is different.

Date stamp of #5
http://i51.tinypic.com/f429z.jpg

Date stamp of other heads
http://i56.tinypic.com/autk69.jpg

Things that make you go hmmm... When I bought the 911, it had harness eye bolts in the rear bulk head and rear floors. And, the second owner had the very old harnesses among his pile of stuff. It's pretty clear it saw some track work back in the day with the original owner. A few years ago when I took off the sump plate to change it, I found a broken valve "elephant foot" up against the sump screen, and now it's evident a cylinder head has been replaced. Clearly, there has been a major failure in the past, possibly on the track. I wonder if it was a broken valve spring, which is a known problem with 78's.

Brett

I got part way through cleaning the case before running out of solvent. I went through about 3 liters of mixtures of hexanes with dichloromethane and acetone (just used everything I had on hand). As a chemist I have access to solvents. I borrow some from time to time. I turned the side to be cleaned on the bottom, so the grime would drip off rather than run down the engine, then just squirted the cleaning solvent from a squirt bottle in one hand and used a wire brush and toothbrush with the other. I placed a plastic trough to catch the dirty solvent. This is the suckiest task of this job, but also one of the more rewarding. This quantity of volatile solvent should only be used with plenty of ventilation, and an activated carbon filter mask would also be a good idea.

Oil breather leak area before
http://i54.tinypic.com/2w1tfec.jpg

oil breather leak area after
http://i51.tinypic.com/35c1pi0.jpg

One side of the bottom almost done before running out of solvent.
http://i53.tinypic.com/2ptv5s9.jpg

The other side of the bottom.
http://i53.tinypic.com/2rysnbd.jpg

Progress!

wow those are pretty amazing pics. Some good detectove work too.. i cant remember which cylinder head studs broke now .. and you are right definitely 5 was replaced. Anybody know why that cylider would have less fins ?

I pulled out my air injectors a while back and put in plugs with copper sealing washers. really cleaned up underneath the engine.

Coulda been a missed shift and kissed a valve. Are the missing fins broken off?

Ice: Broken stud was on #3 exhaust side. Yeah, I know people remove the air injection. I'm embroiled in an internal debate with myself whether to do so. I kind of want to leave everything factory original given this is (or was) a concours car, but... this system is just archaic, and I don't know if the smog pump and air injection valve that are on it now are actually functioning. But then, I'm thinking some SSI heat exchangers would be cool down the road, so there goes my factory original thinking, so why bother keeping the air injection... Decisions, decisions.

Ed: I need to clean the area up and have a better look at the fins, but I don't think they're broken off. I'll get a closer look when the heads are off. I got a question for you. I've pretty much made the decision to have the heads refurbished. The oil pooled against the one intake valve bothered me, and I figured, I'm in here now, just do it. Upon reading posts on the matter, it appears the cost wasn't as high as I thought (around $1000 versus I thought around $3000). 2 questions actually. Where to send the heads? Any recommendations for something local so I don't have to ship them. And, if I'm having the heads refurbished does it matter what cylinder they came from? Should I still label them and put them back on the same cylinder they came from? It would seem to matter less, if you're having all of them redone.

Brett

I don't believe it matters on remounting on the same cyl after refurbimg, but I'm superstitious, and did it anyway. I used a punch on the bottom fin to mark them.

There is a machine shop in Chula Vista or thereabouts that I had some chamfering down at. They advertise in the PCA Windblown rag. I not sure about a complete head rehab though. Ollies is in Lake Havasu and know their stuff, and I believe Competition Engineering a bit north of us that has a good rep.

I mounted mine to a piece of 1/2" ply and then put them in a box to CA from TX. That worked well to ship. Insured the hell out of them too.

Thanks, Ed. Good tip on shipping. The "missing" fins on the cylinder head are not completely missing. Just a little of the top is not there as you can see in the picture. Like I said, it didn't look broken or even machined that I could tell. Looked like it was cast that way... But, I'll report more later.

I just called Dieter's, and they use Motor Works. They guy at Dieter's said Chula Vista, but it looks like their address is actually National City. That's probably who you're talking about. I have seen their ads in The Witness. I think that's good enough for me. I'd prefer not to ship the heads.

Brett

""I think that's good enough for me. I'd prefer not to ship the heads.""

I agree. This has been a bad month for me with stuff lost.

Re shipping:

Brett, as you know from my recent thread, I am having the heads re-built now too. I originally was thinking of shipping them to one of the gurus in the U.S., but I have had things lost in business shipments, even with FedEx (rare, but it has happened). As such, I decided to find a local shop that can do the work. Luckily the Toronto area has some very good ones.

Sure, you can insure stuff to the hilt, but it would be a huge pain. I think our choices to "go local" make a lot of sense, where practical.

BTW, interested in starting a support group for "WYIT" sufferers?

i'm joining

only reason i am not changing my $2.00 oring between the chain box and cam tower ? .. figure it will cost me about 5 grand ..

It is Natl City. I'm not too impressed with what they did to my valve stem seals. Hopefully, you have better luck...

That's pretty funny, but probably true. I've got oil grunge emanating from those cam O-ring locations, too. The cylinders are still a big unknown. The head refurbishing looks like it will be much cheaper than I was expecting, but I just looked at new cylinders on Pelican Parts. I don't want to have to go there.

Brett

Tackled clutch removal last night.

Pressure plate removed. Here's the flywheel in situ.
http://i53.tinypic.com/2l9evs.jpg

Ring gear temporarily bolted to the flywheel to engage the flywheel locking tool so I can remove the flywheel bolts.
http://i51.tinypic.com/339spax.jpg

Flywheel removed. Minimal oil from the rear main seal. Looks good. But, it looks like the rear seal is replaced as a matter of course with the clutch. I see the rear seal is included with the Pelican Parts clutch kit.
http://i54.tinypic.com/2ztc0fb.jpg

Here are the clutch, ring gear, and pressure plate on the bench. No rubber centered clutch.
http://i53.tinypic.com/15wghfd.jpg

The clutch disk is a little over 7 mm thick.
http://i52.tinypic.com/2v16dcm.jpg

How thick is a new clutch disk? What is the minimum spec? I'm thinking I should replace it now. Whoopee!!! There's another $1000.

I'm also in the middle of alternator bearing replacement. I'll put up a full pictorial DIY post when that is done. I'm just waiting for the front bearing to arrive in the mail, and I can put it back together.

Brett

Brett: Your flywheel looks very good. It should be very easy to resurface (i.e. minimal machining).

Mine was not as good. The disc and pressure plate looked quite new, but the flywheel showed evidence of gouging from rivet in an over-worn disc. It looks to me like the clutch was replced without the flywheel being addressed. As it is, it looks like I still have enough material to machine, so I am lucky.

Looking good!

+1,000,000,000.01 That is SOOO funny and SOOO true!

This is how it all starts.

Im in Chicago, I can look up clutch specs when I am home this weekend.

Yeah, it is like a mirror but with some surface rust from sitting for the last 3 years. Machining? I was thinking a little steel wool to knock off the rust and put 'er back in. But, you may be right, a little machining to at least make things perfect...

Brett

Actually, machining is probably not necessary... Was your clutch action smooth? The only other reason to machine might be if there is a slight warp on the surface...

Fantastic thread Brett... am following with interest! I can't wait to get my hands on a 911 engine..... :thumbup:

A 911 engine on paper, or in my mind, was/is quite daunting. The reality is, it is just different. It really is straight forward, and there are a lot of parts, but with the exception of checking all of the clearances and ensuring all of the many mating surfaces seal, it makes sense as you put it together.

Got the cam sprockets and tensioners off. Loosening the 46 mm camshaft nut wasn't difficult on my own. You just have to work for a minute to find a good orientation of the wrenches and your body where you can provide leverage. A pair of Craftsman 1/2 in and 3/4 in flex-handle breaker bars alone was good enough (no cheater pipes needed), and I'm not particularly strong.

Here is a pic of the oil leak from the O-ring on the backside of the chain box. Really made a mess. Both sides were leaking like this.
http://i53.tinypic.com/2chxtg3.jpg

The cam housing is like swiss cheese. I always found it confusing until I finally got a good look inside when I did my first valve adjustment a while back. The pic above is the exhaust (bottom) side. Certain areas under the valve cover are "open" and others are fully enclosed inside the engine as I labelled. I show the path of oil flow from the camshaft to the oil return tube back to the sump.

Here's the left side chain box with sprocket and tensioner removed.
http://i54.tinypic.com/346x93c.jpg

And the right side.
http://i54.tinypic.com/mheu4g.jpg

There was a lot more dirty-looking residue on the metal inside the boxes than I expected to see.

A pic of the circular plate and the O-ring that is supposed to seal off the chain box. It also has a triangular gasket to seal the cam housing where the camshaft comes through into the chain box. Actually, this leakage I'm seeing could also be from this gasket.
http://i55.tinypic.com/6r65iu.jpg

The cam housing and heads come off next as one unit.

Brett

Brett that leak looks very familiar .. so I would have to do everything you have done so far just to change that o ring and gasket :)

THere was some discusion a while bakc on this gasket When James in Seatle did this exact Job. Zimmermann insisted put the gasket on dry but james sprayed it with some sealer or oemthing before install. Not sure if it leaked but i might consider such a thing when the time comes. We have a lot of products and technology not available 30+ years ago and a leak at this spot is a real pain. I bet there are more than just our cars leaking here.

I think I did Curil at that seal. I'd have to look at my notes. Be sure and use the green (Viton) o-rings as replacement.

Hey, looking good (and quite familiar)!

My engine had the later cam bolt arrangement and I really needed the 9191 tool to counter-hold the sprocket, as it was very tight. Some have said they just use an impact on that nut (i.e. on the later cars), but this seems very chancy to me as all the load will transfer back through the intermediate shaft.

I guess you will be removing the rockers after you pull the cam tower/heads?

Cylinder head removal. It's just 12 barrel nuts, and the heads and camshaft housing lift off as one unit.

Someone's been in here before, and he wasn't a very scrupulous mechanic. I have found a hodge podge of fasteners in places. Engine tin had some screwdriver fasteners rather than 10 mm bolts. Intake runners had a mix of 12 and 13 mm nuts. And, now, one cylinder head had frickin' little spring washers under the barrel nuts rather than the proper thick washers.
http://i55.tinypic.com/dy20kg.jpg

The barrel nuts are a little rusty.
http://i56.tinypic.com/dvsjzb.jpg

It appears this job has been done before. The exhaust side studs are shiny while the intake side studs are dull. You can see some leakage from where the stud is broken in this pic, too.
http://i52.tinypic.com/10qcn0o.jpg

Another view of dull intake studs and clean exhaust studs.
http://i51.tinypic.com/1ny0c3.jpg

Another view of the leakage around the broken stud.
http://i52.tinypic.com/xofdwj.jpg

Heads and cam housing lift off as one assembly and get put on the bench.
http://i56.tinypic.com/2j6web.jpg

Combustion chambers of 4, 5, and 6.
http://i52.tinypic.com/9gaqac.jpg

Combustion chambers of 1, 2, and 3.
http://i56.tinypic.com/pefc.jpg

Closer up pic of the leakage around the broken stud. There is not metal erosion, so it wasn't leaking hot gasses. Looks like just seepage of oil/fuel mix.
http://i51.tinypic.com/nf48w0.jpg

Close up of carbon build up on the combustion chamber to show the thickness.
http://i54.tinypic.com/23m4v2t.jpg

wow great pics. I hope they stick around as some are archived and dont show anymore. So what next Brett just replace the stud and start bolting her back together ? I guess a lot will depend on Budget . Does this have to go out to a machine shop now to have that stud removed ? somehow that lock tight has to be melted so the stud can be removed. Now it gets interesting.

I had made the decision to have the heads fully refurbished after seeing what looked to be oil pooled against one of the intake valves when I looked more closely at all the valves. I figured it must have been from the valve guide. The car did sit for 3 years. Anyway, I recalled having a compression test done as a post-purchase inspection in 2004. I looked back at the records, and the numbers were 125 to 140 psi. The shop recommended not doing a leak down test given that the compression numbers were decent. Since then, I put on just 10,000 miles. The heads may be perfectly fine. Or maybe just guides are needed, and the valves and seats are OK. I got smoke clouds on cold start, but no typical oil smoke indications of valve guide wear when driving.

I intend to take the heads, cam housings, pistons and cylinders, and chain boxes to the machine shop for a good cleaning. I'll let them do their thing and make their recommendations on what to do with the heads. I want to have them measure and evaluate the pistons and cylinders as well.

I expect I'll remove the studs including the broken one myself, which reminds me I still need to get the proper stud removal tools.

Brett

i would certainly let the machine shop take out at least the broken one hre .. I am all for DIY but taking out a broken stud i would leave to the profesionals since you have it this far apart .. especially if you have nothing to get a hold of.

In the pics the cylinders have not yet been removed from the case. The broken stud does project above the case, but I'm not sure how far, yet. There are cam activated stud grabber tools, which I'm sure will work to grip the broken stud, or maybe even a small pipe wrench will do. But, I do need to see what's on the forums about best methodologies for this task.

Brett

Hey Brett, thank you for the tip re. the tensioners...

John Walker described a process for broken studs that I think sounds good: Weld a hex nut onto the end of the broken stud (after first cleaning and dressing). Then, use heat on the case where the stud threads into (mainly on the side of the cylinder opening adjacent to the threads) to soften the loctite. It sounds like oxy-acetylene or at least MAPP gas is needed to get the temperature needed at that point (as aluminum transfers heat so quickly).

This is likely what I am going to try...

It didn't take an inordinate amount of heat to pull my studs, but it did require heat. Supertec sells some seriously nice studs, a bit less that ARP, IIRC. Henry developed them for his race motors, and I thought they were a good balance of cost and performance, so a set went in my engine.

I decided on the coated, full-threaded factory 993 studs. Bought them a long, long time ago in anticipation. LOL

Ed, Did you break a stud?

Same to you Alan, Do you have a broken one? And I thought I read Dilavar doesn't weld well. I'll have to look into that. (Well assuming the studs are Dilavar. Need to get out the magnet.)

Both 3.2 L. Just curious. I understand it's more of a problem with the SC engines. Looks like my engine's on its second round of exhaust studs and at just 55,000 miles (to the best of my knowledge). But, I also understand it's the lower mileage cars that have more problems.

Brett

No, I had no stud issues, but my lower studs looked terrible, on an otherwise pretty decent looking engine with no other corrosion. The 993 studs are a great choice too, particularly when you have them in stock! I think they are costly nowadays, which is why I opted for $582 Supertecs.

Supertec is a good source for gaskets and seals-he can customize a package for only what you need, and provides the Viton o-rings.

oh right Brett forgot you still had to pull the cylinder off.. if you got lots to grab shouldnt be an issue .. i am sure we will see pics of the carnage ;)

Awesome thread Brett. The pictures are worth the price of membership alone. I've been following without the time to chime in...and you have good advice already. For the o-rings, i always apply a thin coat of the Dow 111(or whatever it is) silicone paste for assembly. As for the heads, By all means have them checked out. At bare minimum, hand lap the valves yourself...it's easy and kinda fun. Air cooled motors ask a lot of their valve train in terms of cooling and the guides should certainly be in check if you are "in there". In years past, I have sent several sets of heads to Andial and they always do a great job.
I also recommend a good look at the pistons and rings. If you need to rering...do it. I just did the DIY alusil reconditioning on my 924S motor(944) with the Sunnen AN-30 paste and it was so easy I would have no problem suggesting any novice do this at home. I'll send you my AN-30 paste if you need some...there is plenty left. I went with Goetze (OEM) rings that I fitted to each cylinder and was satisfied with their fitments. I know this is a highly debated subject in the 911 community, but It was a no brainer for me when it was over with. I have 800 miles on my motor now and it is tight; I know it will be fine. Keep it up and the picture are superb.

No, I don't have any broken studs, but I can't resist the temptation to replace them while doing the rest of the motor. My studs on the bottom (exhaust side) are coated in a black finish and I think those are Dilavar (still need to the do the magnet test myself). The intake side studs look to be bare steel and have light corrosion in places.

If I may go out on a limb...I do know that Porsche 'upgraded' the head-stud nuts for the 993. As I understood it (in factory training) that the shape was changed for better airflow(?). If you have the studs, I would suggest the associated hardware be used/replaced. This may be worth a little research on your part as I don't know the compatability on older cars. Just a thought.

Whalebird: I have purchased new head stud barrel nuts and washers. I was not aware of different hardware for the 993 studs. I'll look into that. Thanks for your comments.

Brett

A quick google seach revealed that yes, the 993 is different; sort of mushroom shaped. If they are usable in a 3.0 remains a question. I would think you are fine with what you have if nothing else, again I'm thinking out loud.

I've said that I thought that my engine is on its second round of stud replacements based upon the remaining shine on the exhaust side studs versus the general dullness of the finish on the intake side studs. That may not be the case. I have finally realized the intake side studs are steel (magnetic) whereas the exhaust side studs are dilavar (non-magnetic). The difference in appearance may not be due to age but just the materials used. It's possible that the exhaust side studs are still the original dilavar studs. Upon re-reading the literature on head studs, the steel intake side and dilavar exhaust side arrangement was in use during this period of production. Nevertheless, someone has been inside this engine before as noted by the slipshod use of fasteners, the different #5 cylinder head, and the broken valve tappet (elephant foot) that I found a few years ago in the sump.

I have now removed the pistons and cylinders. Nothing to report about the process, just did what Wayne Dempsey says in his 911 engine rebuild book. The cylinders slid out easily. Then pistons were removed from the rods.

Looks like I have nikasil cylinders. "Mahle" is cast into the base of the cylinders, which means it's a good chance these are nikasil. Checking with a magnet confirmed that the cylinder walls are magnetic. Alusil is non-magnetic

Pic of "Mahle."
http://i54.tinypic.com/2w1w295.jpg

As far as being able to ID the cylinders without removal... The "Mahle" is cast in the side between the cylinders. You can see well enough between the cylinders once the cooling guide tinware is removed to make out the letters. The two cylinders with oil grime are #s 5 and 6, more fallout from the breather hose oil leak.

All the cylinder walls look pretty similar. Cross hatching pattern still very evident with some visible score marks straight up and down. Most of these score marks cannot be felt with the pointed tip of a pick tool or can just barely, barely be felt. On #5 however, there is one particular score mark that is much deeper and more palpable with the pick. Could be bad news for this cylinder... I don't know. I've never done this before...

The score mark on #5
http://i52.tinypic.com/23sztbn.jpg

The pistons were pretty much identical in general appearance.
http://i52.tinypic.com/2rdvtvl.jpg
http://i51.tinypic.com/w722he.jpg

Most showed a little light wear patch on the skirts just below the rings. At least, I think it's a "light" wear patch.
http://i54.tinypic.com/fnqvxv.jpg

But, piston #5 had two little flaws on the very edge of the crown. They almost look like casting flaws, but maybe it's some kind of damage. Again, I don't know due to my inexperience, but it may be recommended not to reuse this piston. These flaws do not line up with the score mark pictured above on the wall of the #5 cylinder.

http://i51.tinypic.com/20ztut0.jpg

All the wrist pin bushings looked exactly like this one. Some silver colorations on the crank side of the bushing. Again, I don't know what this means. The wrist pins themselves looked flawless. You can also see the broken stud.

http://i51.tinypic.com/2h2mx42.jpg

Here's a pic into the cylinder spigot showing the piston squirter.

http://i56.tinypic.com/2quoo68.jpg

And, here's another view of the broken stud on the exhaust side of #3.

http://i54.tinypic.com/2wptqix.jpg

Brett

I read that one of the changes to the later cars (3.2 Carreras and maybe later SCs - not sure on that) was that Porsche started coating the Dilavar studs with a black "paint" of some type, which matches what I see on my engine. This may partly explain why broken studs do not seem to be quite as common on Carreras as SCs.

I will soon have my pistons and cylinders out this week too. It will be interesting to see what similarities and differences may exist.

Great pictures as always!

Outstanding pics . I wil be interested to hear what some of the experienced engine builders have to say about some of the pics. Steve W hasnt been around for a bit but i am sure he would have some great insight.

Yeah, in my last picture, you can see the corrosion on the other #3 exhaust side stud. So, anything done to stop the beginning of that corrosion is a good thing. The head studs all the way through the 993 Turbo were still made of dilavar but are coated with a black coating, and there is never an issue with those breaking. The coating must make the difference.

Are your intake side studs steel or dilavar?

Brett

Me too. I'll probably cross post a few of these pics on the pelicanparts engine building forum to get some more exposure to highly experienced folks.

Brett

Hi Brett, having done the magnet test, I can confirm that my intake studs are steel, and exhaust studs are Dilavar. I am still debating what to use for the rebuild. All-steel OEM (intake and exhaust) seem to be a well-proven option for normal builds. However, the 993 studs you are using have a very good rep and of course there are the Supertecs, Raceware and ARP options.

Right now I am leaning towards OEM steel as I think they should be appropriate for my application and "affordable"!!!

All rocker arms and the camshafts have been removed from the cam housings. Things are not looking good.

The rocker arm cam following surfaces weren't so bad. They all kind of looked like this. Only this one showed this bit of rust.

http://i53.tinypic.com/30seplh.jpg

Trouble spotted when I got to the #2 intake rocker. Yes, those are all pretty deep gouges in the rocker shaft.

http://i55.tinypic.com/15zp3pw.jpg

The bushing wasn't much better. Here's a couple of views of rows of pits. These are two separate rows going across the bushing in slightly different locations.

http://i54.tinypic.com/ifmmwz.jpg
http://i52.tinypic.com/33137dz.jpg

The other shafts and bushings weren't anything like that bad, but there may have been loose tolerances. I think they should all be rebuilt.

The cams came out next. They just pull right out once you've removed the rocker arms. This was the first one I pulled. Uh, oh. One tiny pit in one lobe. That's one tiny pit too many. Looks like I'm headed for a cam regrind.

http://i53.tinypic.com/s3kdhc.jpg

This was the second cam out. Even worse. Two lobes had significant pitting. This pic is the worse one. Definitely heading for a regrind.

http://i55.tinypic.com/263avdu.jpg

I'm concerned about the bearing surfaces of the cam housings, too. I don't think the visible circumferential lines are an issue, but there are a lot of little pits in the surfaces. They are small but palpable with the tip of a pick tool, and they are numerous. I'm not so sure these cam housings should be reused. More expert opinion will be necessary. Here are a couple of pics of the bearing surfaces.

http://i56.tinypic.com/qwykbn.jpg
http://i54.tinypic.com/50h7jq.jpg

All this is obviously concerning. I was not intending to split the case, but the wear evident on some of the top end bearing surfaces makes me wonder what the bottom end looks like. Maybe I better have a look. There is also some extra goop smeared around a couple of case fasteners on the bottom side of the case, possibly an attempt to stop a case leak... so, splitting the case and getting a look at the bottom end is probably the best path forward at this point.

I thought this was a low mileage car, 44,000 miles showing when purchased from the second owner in 2004. I didn't have many records, but I did have a couple of shop receipts from the year 2000 from the original owner showing 39,xxx miles. What I'm seeing makes me wonder. As I mentioned before when I found the different cylinder head, this 911 did see the track with the original owner as evidenced by the eyebolts installed for harnesses, and presumably, there was a major failure leading to some major engine work to the extent of putting in a different cylinder head. Perhaps this wear I'm seeing stems from metal bits circulating through the oil system from this failure. I don't know, but I'm thinking I had better get eyes on the main bearings and crank journals.

Brett

Local to me:

http://www.webcamshafts.com/

:bowdown: check out page 52

Yep, I'll be paying Web Cam a visit in the future. As costs continue to mount for this head stud replacement, it may be longer in the future than I wanted...

Brett

I'd definitely split the case to see what's going on.

Webcams is a good company, I'm sure, but there is another gentleman, John Dougherty at Dougherty Racing Cams, who does a lot of Porsche cam work. Yes, he does stock specs too. Much more reasonable in cost than webcam, IMO. He can also rebush/surface the rockers.

PS to Doug: See???

I am sure Steve has talked about this before and he has commented on this type of damage on fairly recently rebuilt engines. I wonder if this is the net effect of pulling zddp out of oils as it seems to me it would hit the cam lobes and rocker arms first. i am not sure the bearing surfaces would be an issue as the bearing sits stationary against them but i really have no idea. The pitting in the piston looked concerning. Could this be the result of pinging ?

Some sad news there Brett but the lessons learned here and the pics are simply outstanding. Sorry it has to be at your expense. I am kind of afraid to look at the lobes on mine now the next time i do a valve adjust.
I wonder what would have happened if you had just put a stud in and buttoned it back up . I am sure this has crossed your mind. What would th enet effect be .. just less power ?, i dont know what pitting lobes would cause and am kind of wondering what symptoms i would see.

Other thing is that engine seems awfull dirty and used for a 40,000 mile engine . Other with More experience would know for sure I guess

Anyway for what its worth keep up the great work .
P.S. what oil were you running ?

lot's of options in the catalog. (I excite easy :()

Cam options are an exciting subject at the expence of many fun-tickets.
I would split the case, inspect and replace everything accordingly. I would not reuse any of those cam housing/rockers/cams without them being refreshed or replaced. And I would not refresh/replace the valvetrain without looking inside the case. You're way to far along to short stop your efforts now; this is why you took all this apart in the first place.
For cams: webcam is great for sure but Ed is ringing the bell for John and I would suggest a call or visit to both of them. A few extra dollars at this point will get you some extra ponies as well...but you should have a nice exhaust too. It never ends does it?

Myself and Ed mentioned the Ti valve spring hardware in the other (battery area) thread. I won't regurgitate my rant over there and I think you may know most of it anyway Brett. But if you do go with a more agressive cam (usually increased lift in the case of injection, as duration will create overlap) the valve has to move farther in the same amount of time...this increases valve velocity and load on the cam/rocker. The lighter weight Ti hardware is good insurance, especially if you are going to track the car. Many will contend that stock valve hardware is pretty good though.
Just part of the discussion...I like these threads and get a kick out of spending other peoples money. I tried like hell to extrude-hone Ed's wallet on Ruby's Redux.

Wow Brett, we are both locked into full rebuilds now! You wanted to fix a broken head stud and I wanted to replace the fuel lines & various seals and look where we are now!!!

For my part I can confirm that the damage/wear on the cam tower, rocker face, rocker shaft & bushing in those photos looks extensive. Those parts on the motor I am disassembling all look virtually perfect, and it is a 107K motor that has never been opened. This suggests to me that your theory that some of the carnage may be due to a previous failure event may be very likely. The other thing I wonder is whether the previous work left some dirt in the system? I only mention this as I share your dismay at some of the inappropriate hardware substitutions (i.e. some of the washers for the head stud nuts). A mechanic that would take those kind of shortcuts may also not be scrupulously clean as well.

Of course, it is all quite fixable with money. They key will be to get expert opinion on what can be successfully restored vs. what must be replaced. The silver lining is that if you have to start replacing some of the expensive parts, you may be able to chase after some performance upgrades for not much more $$. In my case, I know if my P’s & C’s don’t spec out, I will be looking at Euro versions (higher compression for the 3.2).

Appreciate the comments from all. Ed, I will definitely look up John Dougherty when the time comes.

I'm not a HP junkie. More of the concours type. I don't see myself upping the internal specs of the engine at all except for any reliability upgrades that are recommended. Stock rebuild is good for me (At least that's what my mind says now). I may fancy a set of SSI's in the future perhaps.

Ice: The engine may have gone for a long time as is (well, if the head stud hadn't given up). It did not have excessive oil consumption. But, I'm here, so all will eventually be done correctly. I just hope the crank journals aren't beat up.

Brett

I finished separating the heads from the cam housings this evening. Bank 2 was tonight's task.

I don't think these gouges in the cam housing came factory installed.
http://i55.tinypic.com/ei05xu.jpg

Just another view of the same thing.
http://i54.tinypic.com/210gbnt.jpg

This is the area right below the spinning cam shaft. Any foreign object in here is going to get bounced around by the cam lobes. More fallout perhaps from a serious failure. Well, at least the first owner put the original engine back together rather than dropping in a replacement. I like the fact that it's a numbers matching 911. I would have bought this 911 without an engine (probably for the same price) just for the disco era continental orange/lobster color combination.

Knocking the cylinder heads off of the cam housings was a bit stressful. Mr. Dempsey describes the process as tapping the heads off the housings. I would call the effort needed for my heads as much more than tapping but short of pounding on the studs. The refrain repeating in my head the entire time while working on the first cylinder was, "Am I supposed to hit it this hard. Am I supposed to hit it this hard..." Finally, it broke loose, and only then was it just a matter of tapping to work the head off. I used a hammer with a sturdy punch placed on the studs.

I found the height provided by some pieces of 2x4 and 4x4 to be perfect for the task of supporting the assembly during head removal. Just a few pics of the process.
http://i51.tinypic.com/azc67b.jpg

http://i54.tinypic.com/34pbz8h.jpg

http://i55.tinypic.com/2pq3spz.jpg

http://i54.tinypic.com/rs4dat.jpg

http://i56.tinypic.com/scqgbt.jpg

http://i52.tinypic.com/34fy7b4.jpg

Brett

Maybe this car had a on-track incedent like a missed shift/over rev. Also, if in a spin, the driver doesn't get the clutch in fast enough, he can turn the motor backwards when it comes around. All this can possibly break a rocker/bend valve etc. Who knows, but I don't think this kind of damage is uncommon in these older cars.

In my case I removed the cam tower while the cylinder heads were still bolted on and it did need just some tapping to release. I guess each order of disassembly has its pros and cons. I can see that it would be nice to remove the rockers with that sub-assembly on the bench...

Removing the rockers was the least fun part of engine teardown for me.

Yeah, it was nice to work at the bench on rocker removal. There's a lot of picking up and putting down tools during the process. When working on the bench, they're all right there on the bench next to you. The only issue was removing the nuts to the cylinder heads. I needed to hold the head/cam housing assembly against rotating otherwise it just turned on the benchtop with any force on the wrench. I ended up using a C-clamp to clamp a small block of wood to the edge of the bench. One cylinder head was set against this block, and then I put another block of wood between the cylinder head on the other end and the wall. No problems, then.

As I was "tapping" my cylinder heads off the cam housing assembly, the assembly was sitting on blocks of wood, and the blocks of wood were sitting on a sheet of cardboard. I imagine the softer materials dampened not only the impact and but also the high frequency vibrations caused by tapping, which contribute to breaking the bond between the parts. I don't know... All I know is I did have to whack the studs pretty good to break the heads loose.

Brett

I got the head studs removed tonight. I wasn't going to put in new intake side studs (They're steel.), and upon looking at them more closely, I don't think it was necessary at all. Visually, they all looked in good shape. But, upon making the decision to split the case to get a visual on the main bearings and eventually have the crank measured and evaluated by a machine shop, I figured, why not change them. It'll be easier to transport the case to the shop for cleaning and evaluation, too, without the studs sticking out. At this time, I am expecting to replace them with the same OEM steel studs.

I found that a small pipe wrench was a sufficient tool on my studs. Here's a pic of one stud in process.
http://i52.tinypic.com/2ly4wu1.jpg

I ended up using heat on only 9 of 24 studs, and I may not have needed to use it on that many. I used a MAP-Pro/air torch. I don't have an oxy-gas set-up. On the first row of studs that I removed, the first two I did check for resistance before applying heat, and they were stuck in there pretty good. So those first two got heat. The other 4 on that row and the first on the second row, I didn't check. I just went straight to heating them. They may not have needed it, because after that I decided to try every one without heat, and most came out, even with the relatively small amount of torque that I could apply with the short pipe wrench. It was only the last two intake side studs on the second bank that needed heat again. I applied the flame as described in the Wayne Dempsey engine rebuild book, on the wall of the cylinder spigot adjacent to the stud. I gave it about a minute of heat before turning the stud, then kept the heat on for a few turns.

I noticed that when I didn't heat the studs, they came out cleaner. The heated studs had a grey residue in the threads (presumably the decomposed thread locker). As easily as some of the studs came out, particularly the exhaust side studs, I began thinking again that maybe they had been replaced once before, and not much or no thread locker was used.

http://i56.tinypic.com/21mdreo.jpg

Removal of the broken stud wasn't that bad. I was concerned because this stud was broken in a potentially tough spot. It was close to the rear of the engine case where it flares out to surround the flywheel, and it was broken short such that there was no clearance above the case. This is the hardest possible situation for getting a wrench on the stud. Fortunately, I had read some threads on broken stud removal, and one of the suggestions was to grind flats on the stud and use an adjustable wrench on it. That worked brilliantly for me. And, fortunately, this stud was not bound in very strongly by thread locker. It backed out nicely with the crescent wrench.

A couple views of the grinding job with the stud still in the case. I put a cut piece of cardboard over the cylinder spigot to minimize entry of junk into the case.
http://i54.tinypic.com/x1j1pe.jpg
http://i56.tinypic.com/dpdab9.jpg

Voila!
http://i53.tinypic.com/qx4fis.jpg

And, I thought this whole job would just be about removing and replacing this one tiny little stud. How naive can one be?

Brett

Could be that the goop from the threadlocker is in the case where you didn't heat. Not sure if such a product may adhere to aluminum better than steel.

My studs would not budge with considerable torque when not heated (putting as much force into them as I dared that is...)

I made an attempt at splitting my case this evening, an unsuccessful attempt. I even welded together a spreader tool to apply tension between the fan housing mounts. Then, I tapped and tapped and tapped harder and tapped harder and pounded pretty good with a hammer on a wooden dowel set against the case, and... nothing. I'm off to do some forum searching.

Here's my spreader tool. I didn't see one of these on Pelican Parts. LOL
http://i52.tinypic.com/ae7dj7.jpg

Brett

Hey Brett, were you able to see any slight parting at the seam?

I know this is probably a dumb question on my part, but are you sure you have all the fasteners removed? There is an M10 nut deep in the chainbox... and a few others that are easy to not see...

The spreader looks like it would easily pop the case... well done.

The other thought is if the case had been apart before and was reassembled with some crazy-strong adhesive...

I like the home-made pry bar. Pretty slick.

There are 2 or three nuts that aren't necessarily evident. One or two at the clutch end too, IIRC. It should not take that much effort to split....a few knocks on mine with the rubber mallet had it apart.

No parting at all. Pretty sure I have all the fasteners out, including the 17 mm one inside the case (That one was on there tight.). Before trying again I'll make another check around.

Yeah, I thought a little tension on the case at that point would be my salvation but nothing yet. I meant to search here and on Pelican for any suggestions last night but I fell asleep at the wheel, er uh mouse. This working two jobs has me exhausted. Chemist by day, Porsche tech by night. LOL

Yes, I'm worried about the "crazy strong adhesive" theory. What is evident around the seam is brown and hard and brittle. Tap it with a hammer, and it shatters and flakes off the case.

Brett

Yep, got the ones under the flywheel. Thanks for the comments. Exactly what seems should be the case. I need the jaws of life on this thing.

Brett

that just seems like there are fastners still in there

Seems to me there are either studs expanded with corrosion or thread locker holding this thing together, or some seriously strong case sealer. :confused: If it were one stud there would be some movement somewhere.

I win!!!

Brett Allison: 1
case #6282103: 0

The case is split. Too tired to put up pics tonight. I'll try to get a pic post up tomorrow. There are a few reasons I'm very happy with the decision to split the case.

Brett

..

Congratulations Brett! I'm glad it came apart...

What I liked most about it was that once the case was split, I knew well and truly that there is no going back... you are at the point of maximum entropy and it will only get better now!

Yeah. Almost max entropy. Good choice of words. Still have to get the rods off the crank, but very close to being done with tear down. Tearing down is the fun part. The next stage, cleaning, is going to suck. I'm not sure if I take the case as-is to the machine shop for them to clean off all the old, hardened sealant, or if they expect me to do it. Will they do it and happily charge me the hours, or do they not want to do it at all? Is it easy (mechanized) and quick for a shop, or is it labor intensive and, therefore, expensive for me to have them do it? Oil and oil grime will come off easily with solvents, but this sealant stuff is tough.

Brett

Don't even mess with it. I got the easy crud off, and Ollie's did a great job of cleaning, for minimal cost. They have parts washers and such for this.

So here's the rest of the story of splitting my case. I searched on the Pelicanparts 911 engine building forum, and surprisingly to me, I only found one thread on a difficult to separate case when searching "case separation," but it was helpful.

http://forums.pelicanparts.com/911-e...eparate-2.html

Basically, the guy ended up doing the same thing I was working on, getting creative with spreading tools.

After initially failing with my spreader tool between the fan housing mounts, I decided to tackle spreading the lower side of the rear of the engine between the engine mount studs. Given that the case mating surface is broken up by a couple of large openings (crank shaft pulley and intermediate shaft), it looked like it should be a more weakly bonded area.

Here is a pic of the spreader in place. Just a couple pieces of old bed frame angle iron with nuts welded to one side and some wood to pad the threads on the studs.

http://i54.tinypic.com/29394lv.jpg

I cinched and cinched the thing down expecting the spreader to fly out of place anytime. I decided to take a break for a second and think about banging on the case with hammer and dowel again, and there was a snap sound. Damn, I thought, there goes the wood. Looked at the wood. It's fine. Maybe, just maybe it's... this.

http://i53.tinypic.com/2z3zci0.jpg

http://i56.tinypic.com/2wr261t.jpg

Yep, that's a split in the case. Eureka. LOL

I then put the spreader back between the fan housing mounts and torqued it down pretty good. Nothing. So, I'm fumbling for the hammer and case beating dowels, and pow! The bond breaks across the top side. Scared the bejesus out of me. I'm thinking I broke something, but all was good.

http://i54.tinypic.com/30cqd87.jpg

I even put a little spreader on the breather cover studs to finish off the top side.

http://i53.tinypic.com/xdtbmh.jpg

I put a couple of nuts on studs on opposite corners of the case to catch the falling case half and rotated the case to use gravity to help out with initial separation.

http://i53.tinypic.com/2vanz3k.jpg

http://i56.tinypic.com/2n7h2c9.jpg

As things were coming apart, here's reason #1 that I'm glad I split the case.

http://i55.tinypic.com/n1t7ip.jpg

This washer was floating around the case. You can see it's bent at 90 degrees (already got in the way of something). I thought I was hearing something tinkling around inside as I rotated the case while working on it. This must have been the culprit and would possibly have stayed in there if I hadn't opened things up.

Overall the inside of the case looks good. Pretty clean.

http://i55.tinypic.com/2j3076x.jpg
http://i52.tinypic.com/10mschh.jpg

And, on to reason #2 that I'm glad I split the case. Check out the gash in that main bearing.

http://i52.tinypic.com/ogxt1i.jpg

Others had some small palpable scratches.

http://i51.tinypic.com/juxr49.jpg
http://i51.tinypic.com/309scgm.jpg

The main bearings will be replaced.

Here is the crank journal that corresponds to the badly damaged bearing.

http://i54.tinypic.com/2e651sk.jpg

It's the worst of the journals in my opinion, and it's not that bad I don't think. The markings don't really have palpable depth to them using the tip of a pick tool, but there is a slightly different surface quality as you slide the tip of a pick across it. This bearing and journal also seemed slightly drier of oil than the others. I don't know whether this is indicative of anything. The car has been sitting for 3 years.

The other journals all looked good, I thought. Like this one.

http://i52.tinypic.com/vorjox.jpg

Crank will be measured and evaluated.

And, reason #3 I'm glad I split the case. The intermediate shaft bearing is toast.

http://i54.tinypic.com/dxxw1z.jpg

Brett

Wow great work . I wonder if a lot of our cars look like that .. we just lack the courage to go look ..

Hey Brett, great job!

Unquestionably, you were very wise to take this motor all the way apart. What you photographed are all things that would likely have gotten worse and ultimately manifest themselves as deeper damage. As it is, it looks like you will be able to get a lot of this straightened out. Maybe the crank just needs a polish… Of course, we both know until all our parts are comprehensively spec’d we can’t say for sure…

Looking at the sum of all the things you found, it really does look like your extra challenges here are the result of collateral debris from a previous engine failure that was not completely eradicated during repair, and/or a less-than-pristine job by the last mechanic that took this motor apart. I think your situation is one where following the “while-you-re-in-there” instinct was the right one. It would have been a real let down to just fix that broken stud, button it all back together, and then be dropping it again next year when (perhaps) that intermediate shaft bearing goes over the cliff.

Actually Ice, I think a lot of these motors are still in pretty good shape. As mentioned, I think Brett’s discoveries are more to do with the specific history of the motor (please correct me, Brett, if you think I’m wrong) and less to do with mileage or design-related factors.

When I split the case on my 3.2, everything looked perfect except the outboard intermediate shaft bearing, which was showing copper:

http://i15.photobucket.com/albums/a3...a/P1040465.jpg

The basic mystery I don’t know the answer to is how much more mileage would this intermediate shaft bearing have, before it would start to pit and break apart?

From everything I have gleaned from forum searching here and at Pelican, showing copper on the intermediate shaft bearing is very typical for a +100K motor. Yet, we know many 3.0s and 3.2s go beyond 200K without being split, which leads me to wonder if there is still a lot of life in an intermediate bearing that is showing copper (assuming it continues to see frequent oil changes etc)?

It would be nice if that one bearing could be changed without splitting case!

That looks to have evidence of some pretty thick coat of "adhesive". No wonder you fought it. I'd say the case was split before, possibly when the "incident" happened. They just may not have cleaned all the oil galleys out well, and some crud found it's way to that bearing.

Great work, Brett. Keep on plugging away!

Reasons #4 and 5 that I'm glad I split the case.

There's 1/3 of a tooth missing on one of the timing chain sprockets on the intermediate shaft.
http://i53.tinypic.com/2nqcsow.jpg

And, I found more failure detritus behind the oil pump, which I removed tonight. This is a broken valve keeper.
http://i51.tinypic.com/aauerb.jpg
http://i55.tinypic.com/okbeph.jpg

That makes a washer, valve keeper, and valve tappet that I have found floating loose in the case. This and the tough case sealant that I encountered makes me wonder more about the history of the engine. I can't imagine that the case sealant was from the factory. So, the case must have been split at some point, but also, I can't imagine that these objects were not found and removed when the case was split. Possibly this engine has been apart twice. The first time, the case was split and resealed with the tough sealant for whatever reason. The second tear down was for the top end failure, and the unscrupulous mechanic did not split the case and clean oil passages and remove debris and fix things like the timing chain sprocket as should have been done.

I also lifted out the crankshaft and mounted it on the flywheel on the bench. The other halves of the main bearings were much like those I already posted pics of. No others with significant damage as seen earlier but just a few palpable scratches in them. Rod bearings are next.

Brett

That was my assumption in my post above. But, you're right, maybe the thing was apart twice? Or, "incident happened" they opened it up to clean and replace the one cylinder, didn't catch the big stuff behind the oil pump, figured the bearings "weren't that bad", cleaned the easy stuff, and slapped it together. Unscrupulous knows no bounds, IMO.

The good news is: no apparent major damage, and she'll be as good as new when you're done. Done, minus a few sheckles from the family bank account.

These engines are pretty damned robust, at the end of the day. When I look at mine, and the over-rev that bent all of the exhaust valves, two of the lock nuts on the elephant feet backed off completely in my "incident". My good news is they stayed up in the cam towers, and didn't get down to the bottom end to do damage.

Well, at least you aren’t thinking “Ah, I shouldn’t have bothered wasting my time splitting the case." It has proven to be superb decision on your part.

It is amazing how slipshod some mechanics can be. Of course, this work could have been done by an amateur too, but certainly some “pros” are not deserving of the title.

As Ed says, everything is quite fixable and you will have the satisfaction of knowing your motor is perfect when you are done.

Thanks, will do. That guy from "No Country for Old Men," is a scary looking dude. It happened to be on last night, and I watched some of it again. Interesting choice for your signature. :)

Brett

Amen, to that. It's been very educational, if nothing else.

Brett

I got the rods off the crank last night. It's not good news. Here are some views of the rod bearings.

http://i51.tinypic.com/imi8av.jpg
http://i54.tinypic.com/ak7ejl.jpg
http://i54.tinypic.com/23sw6c1.jpg
http://i52.tinypic.com/sdptsx.jpg
http://i52.tinypic.com/24nffo6.jpg
http://i53.tinypic.com/4kbm9g.jpg
http://i56.tinypic.com/535lci.jpg
http://i55.tinypic.com/34pjcqh.jpg
http://i52.tinypic.com/2hec85u.jpg

And this is the rod journal corresponding to that last bearing. Seems worn through the hardened surface in a couple of spots. Not good.
http://i55.tinypic.com/2e655jk.jpg
http://i54.tinypic.com/ta0g7s.jpg

The other journals seemed visually OK, but don't know about actual measurements. I don't know what this means for the crank. Possibly an undersized grind and rehardening for the rod journals, but I do know it means more money out of my pocket. :(

Well, that pretty much completes the tear down. Well, almost, I guess. It looks like I still need to break down the intermediate shaft to replace the timing chain sprocket, but maybe I'll leave that to the machine shop. It's been an adventure for sure. I got more than I bargained for, so to speak, and it's been incredibly educational, particularly with 500_19B breaking down an engine at the same time that was in much better shape. Comparing and contrasting has been eye opening.

Now that I'm expecting a much heftier machine shop bill, this thread may go dark for a while to allow funds to grow on some trees. I'm certain my dad has been wrong all these years. LOL

Brett

Brett you gotta spill it man .. what are you using for a camera that can provide such clarity on those close up shots ?

When I saw your first picture in the previous post, I thought "Hey, that looks like two of mine, with radial scratches!" And, I figured that your crank throws might be fine too. But then I saw the other pictures and I get it now...

Again, it all fits in with the "story" of contamination left in the motor from some previous event/subsequent work.

I'm not sure how expensive good, used cranks are, but you may want to keep an eye out as it may be an option too.

I agree with you and have also found the teardown experience enhanced by both of us doing it at the same time. It certainly has helped me learn.

Like you, I now am facing the expensive part of the operation. Although I believe I have a good chance of having a relatively small machine shop bill, just the parts alone are a big expense, and one that I had not planned on some weeks ago.

The expense is a lot of the reason my build took 9 months.....I chunked away on parts or machining each month. Once you get to assy, it goes pretty well as long as you are thinking ahead a couple of steps-this is very important-so you don't paint yourself into a corner. The dollars can add up quick.

I'd still have the crank inspected by a good shop and see what its utility (besides a lamp base) may be.

Just a Panasonic point and shoot on macro setting. Then play around with flash/no flash and other lighting and angles.

Brett

500_19B: Yeah, I think it is just an "unthorough" job on the last rebuild. "Just" I say... sheez, as it adds "just" a few thousand to this job.

Ed: Absolutely, the crank will be evaluated professionally. If it's not bent, I'll bet it can be fixed. It doesn't look really serious to my untrained eye. Machinists are miracle workers.

Brett

my condolences on the state of your bearings. i don't think i've ever seen visible metal shavings on the crank like that without catastrophic engine damage (although there was obviously serious damage before, your engine supposedly had been repaired).

your decision to open the case is looking better and better. i don't see how the engine could have kept together in its current state.

I should have mentioned I'm pretty sure the shavings and other tiny metal bits or other chunks of stuff are from removing the head studs or other work during tear down. I don't think they are from the bearings or wear from the running engine. Knowing that I was tearing the engine down completely and sending to a machine shop for thorough cleaning, I did not take great pains to prevent intrusion of junk into the engine case during tear down.

Brett

I don't know. It could also be somewhat of a testament to how strong these engines are. No known symptoms seemingly, other than the broken stud, but look what was going on inside.

Back in the game!! Engine case and all parts went to the machine shop this afternoon. Lots of cleaning and evaluation to start out with.

Brett

Hey Brett,

I just read your other thread in the PP engine rebuild forum and that reminded me that your bores did have some scores on it… I had forgotten… I hope your search for good replacements yields good results. If you haven’t already, you might want to give Don Weaver at EBS a call (EBS = Engine Builder’s Supply http://www.ebsracing.com/ ).

I am getting my new Mahle P’s & C’s from him at a price that is significantly better than what I’ve seen anywhere else. Not sure if he will have your fitment available… He also seems to be knowledgeable about other options and may be a helpful person to talk to as well.

I do hope that you get good news back from the machine shop on all the other bits.

Allan

EDIT: One extra little positive about going with new Mahles (if available) is that they come complete with rings, piston pins and circlips (it all helps!!)

Plus, the set looks like a box full of jewels.

Thanks Allan. I did not realize that about the Mahle P&C sets. Good to know. As I was loading up my parts I came across the wrist pins and thought to myself. Wonder if I'll need new ones of those, too.

Brett

I just met with the machine shop owner this morning to go over the parts. The shop is Motorworks in National City. It's pretty much all good news. The fellow is an older gentleman and has been in the game for a while. I'd call him old school with regard to cost issues, and he was clearly concerned with keeping costs to his customer (me) reasonable. He lamented with me over the cost of new 912 piston and cylinder sets as he's got some 912 stuff going on, saying he used to buy 912 and 356 sets for a couple hundred back in the day. He said he doesn't give out ball park estimates anymore because parts costs are rising so fast. I like him. He's a very practical guy.

Anyway, he's all about re-using what can be reasonably re-used. His recommendation for my pistons and cylinders was to re-use them. They measured fine, and he was not concerned with any wear as he assured me a honing will take care of the surface. He does want to replace one cylinder with a good used one as there was an impact mark at the top likely from a valve. The gouge was above the ring contact area, which was not a problem, but it cut into the top edge where the cylinder meets the head. He didn't like the possibility that the top edge near the head gasket could be weakened, and he felt that the head sealing could be compromised in the long-term, so he wanted to replace it. I'm fine with all of this. I'm not hot rodding this engine or planning on racing. I just want a 3.0 L that runs reasonably well, and will be good for a while once this is done. Perfectly fine with keeping the old cylinders and sourcing one good used one. This engine won't be getting many miles anyway, and stock or near stock performance is good for me.

For the heads, the valve guides were worn and will be replaced. Valves were all good and will just be reground. We will re-use the valve springs and other hardware. The cylinder/head interface will be resurfaced. Camshafts will be sent out to a grinder that he uses often. I didn't bring him my rockers thinking I'd send them myself to a Pelicanparts forum recommended person. But, I think I'll bring them in and at least let him look at them and give an opinion. We will replace the one timing chain gear on the intermediate shaft that had the chunks taken out of a couple of teeth.

The case was good. No issues. The crankshaft was also perfect. No cracks by magnaflux, and it measured to standard specs just fine with no wear issues. The rough patches on the rod journals that I thought were wear in my earlier posts were not wear, but rather they were spots of metal transfer to the journal. It's bearing metal that has stuck to the journal. It will come off with a routine polish of the journals. Lesson learned. I'll be buying a set of standard size crank and rod bearings. Whew.

The big ends of the rods were slightly enlongated and will be resized. Wrist pin bushings will be replaced. Flywheel will be resurfaced. I will have the crankshaft, flywheel, and new pressure plate assembly balanced. Rods will be balanced.

The pitting that I pointed out in the camshaft housing bearing journals is not a concern. His comment was "oil reservoirs," as I had heard from others either here or on Pelican. Everything measured fine, and the camshaft housings will be re-used.

In total, it looks like I'll be under $2000 for the machine shop part. And, I won't be taking taking out a second mortgage for new pistons and cylinders. That makes me happy. Maybe I'll rebuild my 915 with all that extra cash I'm going to have lying around. lol

Brett

Looking forward to the rebuild!

Hey Brett,

That all sounds really good! The work you're having done sounds pretty similar to my situation. Also, my bill was nominally $2K too, but Brent gave me a nice discount off of that as he took both my old cylinder sets for re-boring cores for race motors. Of course, that discount only partly offsets the cost of the new P's & C's!

Very good thread Brett, I admire your work, and you are doing the right thing by reusing as much as you can.

Thank you for the kind words.

Yesterday and today were homecoming day for the parts. Just picked up the last of it this morning, the assembled cylinder heads.

I have a bunch of pics, and I'll post the final reckoning with the machine shop. It was just a hair over $2000. I thought I'd be under, but it was close.

Brett

Great stuff!!!

I am looking forward to the pictures!

Are you planning to start the build up very soon?

I don't think it will be really soon. I'm not pushing this project hard. I've got a bit of final painstaking cleaning to finish on the case and some other parts, that I'm not too excited about undertaking. lol Still have some parts to purchase, too. Bearings, rod bolts, 12 intake side head studs, for example.

Brett

Here are pics of parts back from the machine shop. I've got 22 pics that I'll split into a few posts.

Pic 1 and 2. One of the cleaned camshaft housings. Cleaned by the machine shop's "dishwasher." It's a hell of a lot better than it was, but as you can see, there is still some stubborn residue to remove using good old-fashioned elbow grease.

Pics 3-5. The cleaned engine case. Again, still some stubborn case sealant and gasket residue to be removed before reassembly begins.

Remember this timing chain gear on the intermediate shaft?
http://i41.tinypic.com/jp7yop.jpg

Its history.
http://i41.tinypic.com/33xy63m.jpg

Reground camshafts courtesy of a nearby outfit called Schneider Racing Cams. Not much to see through the plastic bags, but I didn't want to take them out. It would be an oily mess.
http://i40.tinypic.com/jjptky.jpg

Schneider gives you their own cam assembly lube to use.
http://i40.tinypic.com/v46mau.jpg

Polished crankshaft. Wrapped. Sorry, I'm going to leave it wrapped and protected from contaminants until I'm ready to assemble it.

And resurfaced flywheel.

Connecting rods. These were rebushed and balanced. Initially, the machinist mentioned resizing the big ends. I can't remember exactly what was said in that conversation. If he was speaking as it being a possibility, or if he said the rods were measured at that time. When I asked about it as I was picking up parts, he said they were in spec and did not need to be resized.
http://i40.tinypic.com/e6rssx.jpg

A shot of the shiny new wrist pin bushing and some fresh grinding marks from the balancing.
http://i43.tinypic.com/fwoz9i.jpg

Some grinding on the big end of one of the rods for balancing.
http://i41.tinypic.com/241a0bo.jpg

Freshly honed cylinder
http://i40.tinypic.com/a0jo5t.jpg

You may remember the scoring that I mentioned on the cylinders during disassembly. Well, the honing process did not remove enough material to completely eliminate the scores.
http://i39.tinypic.com/ieqbe1.jpg

No doubt it smoothed the edges of the scores, but some of them are still there and palpable. Plenty of picky engine builders may toss these cylinders. I'm not picky. lol I know my machinist did not bat an eye at it. I'm not saying it is good or bad to use this cylinder. I'm just saying that I will be using it. For me, I look at it as an experiment. If it causes any premature running issues, then I'll tear it down again, replace the pistons and cylinders and tell myself not to do that again. If I don't do the experiment, I won't answer the question for myself whether one should use a cylinder in this condition. As many (or as few) miles as this concours car will get per year, I expect it will be at least 10 years before there is any possibility of an answer to this question. So, I've convinced myself not to worry.

Past glory. lol You don't want to see a pic of the inch of dust on it now.
http://i44.tinypic.com/5uh8ae.jpg

Earlier I had mentioned the machinist thought he would source a new used cylinder to replace one with a valve impact mark. Upon clean up and honing he changed his mind and recommended going ahead and keeping the cylinder. Here is the damage.
http://i41.tinypic.com/2l9ttox.jpg

The damage on the wall is above the ring contact area, so it's not a concern. Initially, the machinist was concerned about the head contact surface, but after cleaning and smoothing, you can see the alteration of the top surface is minimal and not that easily noticed. I never noticed it during my teardown.
http://i43.tinypic.com/351u4p4.jpg

So, I'll keep this cylinder, and refer to my comments above.

And, at my own peril, I will reuse this piston which shows past work due to valve contact.
http://i39.tinypic.com/2925gg6.jpg

Finally, 3 pics of one of the freshly done cylinder heads. Only parts that were replaced were the valve guides and stem seals. Valves were good and were just re-cut along with the valve seats. Head sealing surface was resurfaced.
http://i43.tinypic.com/206gbxt.jpg
http://i39.tinypic.com/11iooph.jpg
http://i40.tinypic.com/2rctt2w.jpg

And, the final tally for anyone wondering what the cost is like for this kind of thing. I had no idea going in and ended up being pleasantly surprised. It actually was under $2000 as I had expected from the initial conversation with the machinist, but taxes broke the bank.
http://i40.tinypic.com/2vd1efd.jpg

Brett

I thought I'd provide a sort of halfway-there cost breakdown while I'm in a post happy mood. Here's my spend so far.

$2000 - machine shop
$519 - case gasket and head gasket kits and sealant kit - Supertec
$645 - timing chain tensioner sprocket arms upgrade, complete case hardware kit, air injection hole plugs - Pelican
$140 - good used rocker arms and shafts - Pelican forum member (I took the machinist my 12 and these 12 rockers and shafts and said pick the best 12 of the bunch. I have a feeling all 12 were the ones I bought used.)
ca $500 - Carrera tensioner kit - Pelican (I bought this several years ago for this price. I see it's $1200 today. Holy cow. More than double)
ca $500 - 12 993 full threaded coated dilavar studs for the exhaust side + 24 washers and barrel nuts - Pelican
($1100 - full clutch kit - Pelican) Not really an engine expense, but if you're going to pull the engine, you may as well do it if it hasn't been done in a while.

Well, this should be well over halfway there in terms of the costs... I hope. I do still have quite a few parts to purchase, which will amount to several hundred if not more than $1000. The 12 intake side head studs since I decided to replace them mid-teardown, main and rod bearing sets, rod bolts, fuel injection things (intake runner sleeves, various hoses, injector sleeves and O-rings, maybe fuel injectors, maybe fuel lines), yadda, yadda, yadda. Oh, and bead blasting the exhaust and bead blasting and powder coating the engine tin. Maybe a bit of replating on some things. OK, now I'm certain I'm north of $1000 remaining.

Brett

:cheers:

thanks for the write up! I know when I hit the engine stage of the car I'll be contacting you about shops and tech info!

Thanks for sharing again.

Thanks for posting all this info.

I'm in San Diego too (Tierrasanta) and am tearing down my 83 3.0 to replace a broken head stud. In my case the car has well over 200k miles on it. My Step-Father bought it in 84' after the original owner sold it back to the dealership after a year. He used it as his daily driver until about 2007 after which I stored it in my garage for a few years. I guess I got attached to it and bought it off him.

After reading your thread I find myself leaning towards a full rebuild given the miles although I have never rebuilt an engine myself.

I have the CIS off and have been soaking the exhaust nuts in Liquid Wrench for the last few days. I guess if the case is going to a machine shop anyway it's not a big deal if a stud or two back out or snap.

scott.

curious if this engine rebuild has completed?