Newbie engine teardown/rebuild - advice always welcome!

[KTL]

Yes crank polishing needs to be done professionally.

One set of rod bearings looks like typical wear, although very worn due to hard use and possibly thin oil allowing contact with the crankshaft at high rpms. The speckled rod bearings look like failure of the bearing material itself coming loose from the bearing shells.

cgarr can do the rockers if you plan to send him the heads too. He does a nice job refacing the rockers and also installing a low friction bushing in the rocker bore. We have used them in our racecar engines with good results.

I don't think you need to do anything special to the parts prior to reinstallation. The rods should be checked for their bore dimensions, especially since the rod bearings look bad. New rod bolts are a must since the old bolts must be discarded- they are a one time use stretch bolt. ARP rod bolts are a good choice since they are not much more expensive than a set of new OEM Porsche rod bolts.

[zelrik911]

Can you tell if the bearing shells are the 'original' Porsche or a replacement like Glyco, are there markings on the backs?

That chunk of plastic under the valve is a real mystery - could it be a piece of the CIS airbox that fell into one of the ports?

Peter 78 SC 3.0

[GT2BH]

Originally Posted by KTL

Yes crank polishing needs to be done professionally.

One set of rod bearings looks like typical wear, although very worn due to hard use and possibly thin oil allowing contact with the crankshaft at high rpms. The speckled rod bearings look like failure of the bearing material itself coming loose from the bearing shells.

cgarr can do the rockers if you plan to send him the heads too. He does a nice job refacing the rockers and also installing a low friction bushing in the rocker bore. We have used them in our racecar engines with good results.

I don't think you need to do anything special to the parts prior to reinstallation. The rods should be checked for their bore dimensions, especially since the rod bearings look bad. New rod bolts are a must since the old bolts must be discarded- they are a one time use stretch bolt. ARP rod bolts are a good choice since they are not much more expensive than a set of new OEM Porsche rod bolts.

I'll have my rods looked at by Rennsport and make sure everything is within spec. I ran my fingers through the crank and couldn't feel any scratches or anything uneven in the surface, but I'll see if I can get it polished locally.. if not, whats the worse than can happen if I clean it myself with carb cleaner and leave it alone?

[GT2BH]

Originally Posted by zelrik911

Can you tell if the bearing shells are the 'original' Porsche or a replacement like Glyco, are there markings on the backs?

That chunk of plastic under the valve is a real mystery - could it be a piece of the CIS airbox that fell into one of the ports?

Peter 78 SC 3.0

My thought is thats its a piece from the airbox. I will take apart the CIS soon for inspection and will check.

This is the back of the failed bearing.. notice the corner is chipped

[zelrik911]

I am no expert but it looks like the bearing may have been moving inside the rod.
Was it the locating tab that has been broken off at the corner?

Perhaps some more experienced people can give an opinion on this and the origin of the bearing shell.

Peter 78 3.0 SC

[GT2BH]

Originally Posted by zelrik911

I am no expert but it looks like the bearing may have been moving inside the rod.
Was it the locating tab that has been broken off at the corner?

Perhaps some more experienced people can give an opinion on this and the origin of the bearing shell.

Peter 78 3.0 SC

Close inspection of the crank doesn't show signs of the bearing having moved - even when I touch it - but I'm no expert either. And yeah, the locating tab was broken off

Originally Posted by sjry6uj

Post a close up picture of the engine harness. Looks like there are some spliced wires visible. Not a good thing.

Not too worried - getting a new harness from Timmy2

[timmy2]

Originally Posted by sjry6uj

Post a close up picture of the engine harness. Looks like there are some spliced wires visible. Not a good thing.

LOL, your thread has been spammed by a bot. Even Wayne's shipping thread was hit the other day.

[GT2BH]

Originally Posted by timmy2

LOL, your thread has been spammed by a bot. Even Wayne's shipping thread was hit the other day.

That's a very smart bot!

[timmy2]

Not really, they copy someone's post in a thread and repost it. This one happened to be mine from page one.
See it all the time, Pelican is a popular site.
Notice it is gone already since I reported it.

[KTL]

Originally Posted by zelrik911

Can you tell if the bearing shells are the 'original' Porsche or a replacement like Glyco, are there markings on the backs?

Original Porsche are Glyco. So the branding isn't a way to tell originality. Need to look at the date code stamping on the bearing shell.

Once the bearing wants to move, it's going to spin and then the bearing gets completely smeared. Those bearings haven't spun, but they sure do look crappy. Somebody may have scuffed the back side of the bearing to remove the plating and give the bearing some bite in the rod?

If you can't feel any ridges in the crank with your fingernail, you're probably OK. Just clean it up with solvent and then treat it with rust protectant or motor oil. DO NOT leave the crank dry or it will rust very quickly.

[GT2BH]

Originally Posted by KTL

Original Porsche are Glyco. So the branding isn't a way to tell originality. Need to look at the date code stamping on the bearing shell.

Once the bearing wants to move, it's going to spin and then the bearing gets completely smeared. Those bearings haven't spun, but they sure do look crappy. Somebody may have scuffed the back side of the bearing to remove the plating and give the bearing some bite in the rod?

If you can't feel any ridges in the crank with your fingernail, you're probably OK. Just clean it up with solvent and then treat it with rust protectant or motor oil. DO NOT leave the crank dry or it will rust very quickly.

Thanks K - I haven't wiped it down yet but I will make sure its always oiled up

That was the only bearing which was completely gone - I am told it might be an oiling issue. I'll be packing everything up this week and shipping it out for machining and will order all the other necessities as well. Now the waiting begins (and the money is spent).

[GT2BH]

Originally Posted by GT2BH

Can anyone confirm whether these are the original or upgraded chain tensioners?

[KTL]

Those are the later style oil pressure-dampened "Carrera" chain tensioners.

[GT2BH]

Originally Posted by KTL

Those are the later style oil pressure-dampened "Carrera" chain tensioners.

Thanks! So all I need to do is replace the cam oil lines and I'm good. I am stressing out about my shopping cart, don't want to miss anything

[KTL]

Are any of the oil lines leaking? If not leaking, it's OK to re-use them. The pieces associated with the oil lines that are good practice to replace are the aluminum sealing rings and the o-ring on the tensioner "snout" where it is fed the oil.

The o-ring is just for splash sealing the tensioner snout to the chain housing cover. The seal rings are most important. However they can be re-used in a pinch. Only when the seal rings are really smashed (from over-tightening) and grooved are they risky of leaking.

[GT2BH]

Originally Posted by KTL

Are any of the oil lines leaking? If not leaking, it's OK to re-use them. The pieces associated with the oil lines that are good practice to replace are the aluminum sealing rings and the o-ring on the tensioner "snout" where it is fed the oil.

The o-ring is just for splash sealing the tensioner snout to the chain housing cover. The seal rings are most important. However they can be re-used in a pinch. Only when the seal rings are really smashed (from over-tightening) and grooved are they risky of leaking.

Thanks again K. My lines weren't leaking but it would be worth while for me to check them again and make sure there are no issues. I'm order a full gasket kit from our host, I'll check again if it includes all the necessary o-rings

[GT2BH]

Update:

I've packed up the stuff and the heads/rockers are going to Craig (cgarr), rods are going to Rennsport and cams are going to Dougherty. Rods will get checked and ARP bolts installed, and the cams will be ground into 964 specs.

I've placed an order for the 100mm cylinder with 9.5:1 JE pistons from LNEngineering and they've shipped. Craig will take care of the heads to match.

Big order pending from Pelican, hoping it'll be placed by Friday. The tools I've ordered a few weeks ago from Pelican are incomplete and they are ignoring my request to ship partial shipment and leave the last tool until it arrives. I'm annoyed.

[tharbert]

If you have the rods done, rebushed and big end trued, the machine shop will need the old rod nuts/bolts. They are not useless yet. Great progress!

[GT2BH]

Originally Posted by tharbert

If you have the rods done, rebushed and big end trued, the machine shop will need the old rod nuts/bolts. They are not useless yet. Great progress!

I re-assembled the rods and packed them, so they include the old nuts and bolts thanks for the input

[GT2BH]

I started looking at the CIS today, changed a few vacuum hoses and cleaned the plastic bits. What are the main areas I should be tending to while the engine is out? The only issue I had before taking the engine out was that after my MSD installation my idle was at at about 1.5k RPM.