Brett San Diego

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.


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.


And the right side.


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.


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

Brett

theiceman

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.

Ed Hughes

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.

500

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?

Brett San Diego

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.


The barrel nuts are a little rusty.


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.


Another view of dull intake studs and clean exhaust studs.


Another view of the leakage around the broken stud.

Brett San Diego

Heads and cam housing lift off as one assembly and get put on the bench.


Combustion chambers of 4, 5, and 6.


Combustion chambers of 1, 2, and 3.


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.


Close up of carbon build up on the combustion chamber to show the thickness.

theiceman

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.

Brett San Diego

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

theiceman

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.

Brett San Diego

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

500

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...

Ed Hughes

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.

Brett San Diego

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

Ed Hughes

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.

theiceman

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