100,000 mile engine service - a few questions

[granitestategn]

I started working on the engine in my 100,000 mile GN. I want to get this thing back together. I tore it down some more and saw a couple of surprises.
1.) The original nylon timing chain sprockets were pristine, no chips, missing teeth, nada. It's coming out anyway. The tensioner has wear and the chain is pretty loose. I plan to install a stock replacement all steel silent chain with a new Melling stock-style tensioner.
2.) A lot of black deposits on the intake gasket "valley pan", some on both sides, much more to the rear of the engine. It's really hard stuff, won't flake off.
3.) Quite a bit of cam button wear on the front cover. I gotta do something about this. The area is not even close to flat. I don't want to just throw a roller back in. I could take this to a machine shop and mill it flat.
4.) Very little wear at the oil pump gears. I can see a little but can't catch a fingernail on it.
5. Lifter valley was very clean.

A couple of questions:
1.) What are the options for front covers these days? OEM ones seem to be dried up. Doing a search brings up a lot of really old threads. Aftermarket parts store ones were always kind of dodgy. Used good looking ones on ebay don't seem to have the correct part number so I don't know if they would fit correctly. They appear to be the same. I know guys were using Silver Seal ones for a while years ago.
I think TA Performance still sells new ones that they machine in-house. It looks like Full Throttle Speed sells an assembled ported one. Any feedback on either of those?
2.) The oil bypass spring in the OEM pump seems really light. Should that get changed out for a heavier one?

I know about Earl's thread and probably have (20) bookmarks on various computers and hard copy print outs of it in (10) different places. Earl was doing covers to sell for a while but I don't think he still does.

While I have this thing torn apart this far, should I take care of other durability/maintenance items? I'm going to be running an old school Garrett GT61-P so I'm not looking for a 10 second car. I will have an alky system and a rebuilt Stage 1-1/2 transmission and a 3500 L/U TCS 9x11 converter. Getting kicked out at 11.50 for no bar will satisfy me.

I'm changing my valve springs again, this time going with CC 981's. Stock, never opened engine with 100K mile flat tappet cam. I'll do new rear main and front seals.
Since I can pull the rocker shafts easy enough (gotta come out for the springs) I'm thinking of pulling the lifters (keep in order) and pull and inspect the cam lobes and bearing journals for unusual wear or damage.

With the lifters out I can flip it over and take a peek at the main and rod bearings. Inspect for damage. Either put it all back together as-is or possibly upgrade the main cap and rod bearing hardware. ARP bolts and studs? This engine probably won't see another 10,000 miles under my ownership. It's not a daily.

I would plan on using assembly lube since this engine hasn't been run in at least two year.

Any thoughts or comments from the guru's? Anything I missed?

 

[THensley]

That is one nice 100K engine
New seal and a speedy sleeve on the front , new spring in the pump and reinstall. That front cover could be spot faced but if you are not putting a roller cam in it would fly. Chain and gears and your good
If the rear main leak you can live with I would not touch it. If you do and the bearing looks good I would stope there.
I only say this because my 77K looked that nice ,But I was a total NUBE to the Turbo Buick. and I broke it 10K miles later.
It made it 100K , 10 more K is just Childs play ind your hands.

 

[THensley]

That is one nice 100K engine
New seal and a speedy sleeve on the front , new spring in the pump and reinstall. That front cover could be spot faced but if you are not putting a roller cam in it would fly. Chain and gears and your good
If the rear main leak you can live with I would not touch it. If you do and the bearing looks good I would stope there.
I only say this because my 77K looked that nice ,But I was a total NUBE to the Turbo Buick. and I broke it 10K miles later.
It made it 100K , 10 more K is just Childs play ind your hands.

 

[TireFryer]

Steve V rebuilds front covers. He could do the oil pump and mill the front to make it flat again. Just get a timing chain and gears and put it back together! Don’t pop that factory head gasket seal unless you have to. I made that mistake and immediately regretted it.

 

[granitestategn]

I will not touch the head bolts. Let a sleeping dog lie. I was considering taking a peek at a couple rod bearings and the rear main bearing to check for wear. I need to do the rear main seal as it leaks bad and has for years. I was considering replacing the rod bolts with ARP but I don't see them listed. Probably overkill on my build. If I do pull a rod bearing cap those bolts are TTY, correct? Same with the rear main bearing cap bolts? I'm thinking replacing the ones I loosen with stock replacements. Is that the right path?

 

[TireFryer]

I will not touch the head bolts. Let a sleeping dog lie. I was considering taking a peek at a couple rod bearings and the rear main bearing to check for wear. I need to do the rear main seal as it leaks bad and has for years. I was considering replacing the rod bolts with ARP but I don't see them listed. Probably overkill on my build. If I do pull a rod bearing cap those bolts are TTY, correct? Same with the rear main bearing cap bolts? I'm thinking replacing the ones I loosen with stock replacements. Is that the right path?

Mains are reusable. So are rod bolts IIRC

 

[THensley]

If you remove the bolt from the rod you will need to resize the rod.
If the rear main is serviceable should let those dogs lie too

 

[granitestategn]

Rear main is getting changed. It's been leaking for years. One of the reasons I pulled the engine is because it will be easier to do all this maintenance and inspection when it's on the stand. Never heard of having to resize a rod because you pull a cap. That makes no sense.

 

[THensley]

pulling cap is ok. But If the bolt comes lose from the rod or you push in new bolts yes resizing is required.

 

[granitestategn]

I played with the engine a little this weekend. I removed the rocker shafts, pushrods, lifters and cam for inspection. The cam journals and lobes looked perfect. Lifters look like new. Very happy with what I saw there. I dropped the pan and there was some muck in the bottom, but not too bad. No metal and the muck was super slippery, not gritty. The pick-up screen was covered in slippery gunk but no plastic debris. That makes sense because the timing sprocket looked great. I'm pretty sure some of that is shredded rear main seal. I pulled the rear main cap to replace the seal and some of it was missing. I cleaned off the leftover stiff white/grey RTV the factory used and got it prepped to install the seal. My replacement lip seal is an Detroit Gasket grey rubber seal I bought 15 years ago. No metal pins at the split. It was a tight fit to get it around the crank. I'm ready to reinstall this and was wondering which RTV works best? I have a can or orange Right Stuff, little tubes of Loktite anaerobic sealer, black RTV, red high temp RTV. My guess is it doesn't matter much as long as the surfaces are clean and dry, not oily. Also, what's current opinion on staggering the split on the seal and the main cap? I have a new Melling pick-up that I bought a long time ago. I didn't see a screen bypass on it unless it's under the flat piece of sheet metal. For the service this engine will see going forward, I'm not sure any bypass is needed.

 

[TireFryer]

Yikes! That’s a lot of crap in the pickup… did you have oil pressure issues???? I would highly recommend you replace the timing set with a stock replacement with metal gears. That plastic one WILL fail you…

 

[granitestategn]

Already in the works. The main bearing I looked at while working on the rear main seal looked good. Cam and lifters looked good. No external oil pressure gauge so I don't know what was running before.