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-   -   My 1978 3.0 L head stud replacement thread (https://rennlist.com/forums/911-forum/650271-my-1978-3-0-l-head-stud-replacement-thread.html)

Brett San Diego 03-18-2012 01:31 AM

2 Attachment(s)
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.

Brett San Diego 03-18-2012 01:44 AM

3 Attachment(s)
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

Brett San Diego 03-18-2012 02:18 AM

6 Attachment(s)
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

Brett San Diego 03-18-2012 02:35 AM

4 Attachment(s)
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

Brett San Diego 03-18-2012 03:25 AM

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

Amber Gramps 03-18-2012 04:08 AM

:cheers:

Eharrison 03-18-2012 02:11 PM

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.

graups 03-19-2012 01:46 PM

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.

Michael D'Silva 04-24-2016 08:27 PM

curious if this engine rebuild has completed?


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