1979 SC Chewed a Valve - Total Rebuild

[OsoMoore]

I think I found the right thing! This should cover the case and valve covers and a ton of other stuff.

[mikedsilva]

I never use stainless nuts or washers anywhere on these engines.

[OsoMoore]

Originally Posted by mikedsilva

I never use stainless nuts or washers anywhere on these engines.

I was going to use the zinc-coated prevailing torque ones on the engine case, and the SS nyloks on valve covers etc.

Is it recommended to leave SS out entirely?

[Flat6pac]

Remember, prevailing torque nuts distort the studs, not good.
Bruce

[OsoMoore]

This is driving me crazy. Do I really have to order a $200 nuts set designed for Porsche engines?

Do I need to get zinc nickel cadmium non stainless steel nylock nuts for the case, and what kind should I use inside for the oil pump?

[OsoMoore]

Ordered these: Medium-Strength Steel Nylon-Insert Locknut, Zinc Yellow-Chromate Plated, M8 x 1.25mm, 13mm Wide

Two new questions (am I worrying too much)?

First: While waiting for my fasteners, I dry-fitted the case together. No top-side bearings or sealants/lube, just setting it carefully in place. There is this small gap running from 1'ish mm to 3'ish. Is this expected before I crank it shut? Or should it be sitting flush now? This engine was rebuilt once before, 25 years ago.




Second: Two of the bevel washers I removed were newer and not beveled on the inside. Is this a concern? If not, do they have a specific location they should be placed at?

[Flat6pac]

They probably were under the oil cooler but still wrong as those studs get
O ring seals too
The case will pull together.
If you need a couple, PM me
Bruce

[stownsen914]

If you're looking for miscellaneous hardware, Belmetric is a source many have had good luck with.

Edit - not for the beveled washers you posted about above.

[OsoMoore]

It is going to take some time to get the correct o-ring accommodating washers.

I'm considering putting one through bolt in with the wrong washers and no o-rings, and sealing/closing the case so I can proceed. Then, when the washers arrive, I can remove just that through bolt and redo it with the right washers and o-ring.

Does this sound reasonable, or would I risk screwing up my seal job?

[Flat6pac]

I would close all through bolts and leave the ones behind the oil cooler for later.
That way you can install pistons and keep moving along, are the heads back yet, if they are subassemble them with heads, cam carrier, cam and rockers.
Before installing unit of heads, back the pistons down from TDC so an open valve doesn’t hit piston
Bruce

[OsoMoore]

Originally Posted by Flat6pac

I would close all through bolts and leave the ones behind the oil cooler for later.
That way you can install pistons and keep moving along, are the heads back yet, if they are subassemble them with heads, cam carrier, cam and rockers.
Before installing unit of heads, back the pistons down from TDC so an open valve doesn’t hit piston
Bruce

All parts are back and in the garage. So now I am clear to start moving forward. Just feeling worried about that gap at the dry fit, shown in my pictures (above).

Got a 2nd smaller torque wrench and an oiler can this morning, so I can work efficiently and do the light and heavier torquing without changing the wrench as I go.

Probably looking at Sunday before I can get a few quiet hours to work. But I can lay things out and watch videos until then.

[OsoMoore]

I just learned there is a hole down the center of the intermediate shaft, and I need to flush it out. Good thing I haven't buttoned it up yet.

https://youtu.be/lxaiRPlnihg?si=S1bwYWLTMf-5D4Nt&t=542

[snbush67]

That gap is strange, I think a place to look is that the nose bearing pin aligned with the hole and seated. Or maybe the case was previously adjusted and you have time serts or helicoils that have backed out.

Have you fitted the case together without the crank, intermediate gear and oil pump? You have to make sure there is no interference, otherwise you risk damaging your case.

[OsoMoore]

Originally Posted by snbush67

That gap is strange, I think a place to look is that the nose bearing pin aligned with the hole and seated. Or maybe the case was previously adjusted and you have time serts or helicoils that have backed out.

Have you fitted the case together without the crank, intermediate gear and oil pump? You have to make sure there is no interference, otherwise you risk damaging your case.

I pulled everything out and fitted the case that way. Came together perfectly without any gap. So no time serts or such are blocking.

I also cleaned the intermediate shaft center out. Need to pick up a new small-value torque wrench, lay out everything, and then can move ahead. Probably Friday or Saturday.

[OsoMoore]

Early this morning I put the shafts back in, and did another dry fit. Everything came together perfectly with no gaps. I had 2 hours before work, so I dived into the case closing.

Using orings and sealants from the Supertech kit everything slipped together nicely. Briefly had a scare when I dropped the inside-chain-case bolt inside, but fished it out with a magnet.

I'm not happy with the two oil cooler studs, they really wanted to twist on their orings, and I don't (yet) have the right washers for those two. So I'll go back and redo them once the right washers come in.

How does my squeeze-out look?

High-res version: https://i.imgur.com/I5hQs6n.jpeg, https://i.imgur.com/nptaiYS.jpeg

[Henry Schmidt]

Originally Posted by Flat6pac

Remember, prevailing torque nuts distort the studs, not good.
Bruce

And yet, we build every diecast aluminum case engine with prevailing torque nuts, just like Porsche factory did on every Air-cooled engine after the 3.2 Carrera.
Our only difference is that we use Supertec assembly lube and .030" hardened AN washers instead of generic 8mm washers.

[OsoMoore]

Hey Henry, quick question for you - I forgot to put the Down Corning on my o-rings as I was putting it all together. I only oiled the o-rings.

Should I get a new set of o-rings and remove the through-bolts one by one, dress new o-rings with Dow, and put them back in? What would you do on a customer's case?

[Henry Schmidt]

Originally Posted by OsoMoore

Hey Henry, quick question for you - I forgot to put the Down Corning on my o-rings as I was putting it all together. I only oiled the o-rings.

Should I get a new set of o-rings and remove the through-bolts one by one, dress new o-rings with Dow, and put them back in? What would you do on a customer's case?

As long as your o-rings did not shred or squeeze out you should be fine.
The trick behind the Dow 55 is that it lubricates the o-ring during installation but when the o-ring hits 180 degrees, a chemical reaction causes the o-ring to swell while compressed creating an even tighter seal.