advice in my rebuild 3.0m based on tear-down findings
 

so have tore down upper end on my 1980 3.0l with 94k miles (can't be positive that 94k is accurate)

-wasn't planning on doing lower end but now I can't be sure what I have based on what I have found

-do have 5 broken Dilivar head studs, no surprise

-found silicone behind the cam chain housings in the seal area:


http://forums.pelicanparts.com/uploa...1545615464.jpg


http://forums.pelicanparts.com/uploa...1545615508.jpg

-my bigger worry is I found grooves worn in the left side cam chain housing right above the timing chain rail, about 0.025" depth, guessing the cam sprockets were not properly aligned (couldn't get a good picture of it)

-so now I wonder where the shavings went and looks like someone was in there and now who knows what I have


-so asking for advice on next move, do I split the case and do everything now?

I've seen these grooves before. Not sure what caused them, maybe a failing tensioner? Shavings would probably end up in the oil filter.

Splitting the case isn't hard it's a fun learning experience. And you'll enjoy working on a clean engine.

IMO split the case and make sure EVERYTHING is in spec. Otherwise you will be second guessing yourself for ever. I am assuming you are planning on keeping the car.

thanks for the input, figured that was the right thing, just needed others to talk me into/out of it, tore it down now, looks pretty clean, some rod bearings show slight wear thru top surface, crank looks/feels great, will measure up everything

-then hopefully I just have new bearings, chains, seals and rebuild my case, allowing me to move forward with my real issue, the Dilivar studs (5 broken but of course replacing all)

-yes I am keeping the car, but also like you stated it is the right thing to do

Start with a good cleaning, see what measures up and go from there.


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New rings?

Valve job?

Both are normal wear areas.

Maybe the chain gears? Not too expensive, look for worn sides, sharp points as signs of wear. For sure that silicone shows someone had a leak there and went in to stop it. New chains?

With the case apart, if you have trouble getting the broken stud ends out you are set to go to someone with an EDM machine.

Searching Pelican should give you all the advice you could need about what rod bearings to use, and what sealants to use where. Glyco seems fine for the mains.

Cgarr is about two hours up the pike from you, I think, and can do any machining you need, look over rocker arms to see if they need work, etc. Having a machinist you trust handy is a really great thing.

Do you have Wayne's book? By far the best single reference for reassembling an air cooled 911 engine.

When you are done you will have an engine good for another 100,000 miles.

ok was just trying to be talked off of/over the edge, full dive in now, case, crank, rods, flywheel and cooler going to Ollies

-Craig I sent you a PM

-yes doing bearings, chains, will look at chain sprockets, got all studs out

-yes have Wayne's book, been reading it at-nausium for about two years, now I'm ready (I think)

Hi Steve,

Before you buy your bearings do your homework. When I rebuilt my brothers 3.0 there was a bad batch of bearings going around. If need be pm me and I'll see if I can dig up the location where I purchased his set ( a long time 911 engine builder sent me the info ). All of my brothers bearings where made in Germany per the boxes that I received. The one thing that I would've done different on his build was buy a set of aftermarket rod bolts. Most of the other replacement parts purchased where factory Porsche parts. It wasn't cheap so be ready. Are you planning on replacing the p/c's ?

Oh and some of the info in Wayne's book is off. Check online or if you have a factory spec book use that. I have one handy if you need some info.

Take care,

Luke

Automobile Associates of Canton (that is in Connecticut, not China) has the Clevite bearings you want. I think Pelican may carry these, and if so, good to get them here. It was Glyco rod bearings not purchased from Porsche we were finding issues with,

thank you Walt, will follow you guys' advice

thanks for advice Luke, hope all is well with you, yes I will check out bearings carefully, what makes you want non-Porsche rod bolts? ARP is about same price, is that what you are suggesting?

-reusing my P/C, had them cleaned, inspected and Measured, all came back good, they are 9.3 compression, could still see cross hatch

Luke - I have found an error or two in Porsche's little white spec books also. Must have been the kind of "this can't be right" thing for me to notice, though, so if you have some experience you don't get misled. Like navigation, it is useful to compare a couple of references sometimes.

Walt is correct. Purchased all the bearings from Automobile Associates.