Top end only, or split the case...?

[mikedsilva]

Originally Posted by thetorch

Update:

I do not, in fact, have a short stroke 3.2, but a regular stroke (74.4) 3.2. This is news to me.

What I found:
Case: 1982 Carrera 3.0 (date mark 82 41)
Pistons: Mahle 3.2 (marked 95P36++)
Cylinders: Mahle 95mm (marked Mahle 95ZN1++).
Carrera 3.2 crankshaft (marked 930 014 09)
Connecting Rods: 3.2 (marked 930.103.121.2 R)
Heads: 3.2 (marked K1926R dated 7-87)
Cam Towers and cams: stock Carrera 3.2 (Left cam marked: 930 14710)
Oil pump: SC part (911.107.105.1R)

Overall condition is very good. Bearings look unmarred, crank looks excellent. I haven't pulled the rods off the crank so I haven't measured any rod journals yet. Oil pump looks like new. Upper head studs are steel, lower studs were replaced with newer porsche steel studs at some point. They look like new.

My friend thinks I should go to 98mm P&Cs to get to (about) 3.4L. My understanding is that I can have the cylinders bored out to 98 without a problem, and get some 98mm pistons with 9.5 or 9.8 compression. This should all bolt right in, correct? The whole setup is 3.2 from the crank to the cam towers (other than the SC distributor gear on the crankshaft, and the case of course).

Open to (constructive) thoughts on my 3.0 -> 3.2 -> 3.4 idea.

Lucky you!
what induction is on that motor? I might have missed it.. cis ?

I'm a bit new to this but have often wondered if CIS can run larger displacement.. ie, 3.4 or even 3.5?

If you do go the bigger piston route, I would try to get the pistons first, then send them with the cylinders so that they are bored, coated and honed to the correct clearance of the new piston.

The bigger motor can run a bigger cam... your new pistons will be good for valve clearance but your limitation will be the CIS (if you have it).
William Knight has a cam that might be suitable for this build.

[thetorch]

Motec EFI Setup: Single Coil on Plug, Rasant ITBs and a 964 intake.

[otto_kretschmer]

If your oil pressure is good, don't split the case.

[thetorch]

Otto,
haha!

Per my post above, the case has been split. I want to reseal it anyway. Glad I did.

Just waiting for my heads to come back from Walt's now...

[Madness]

First off, beautiful engine and I love your setup. I'm a little jealous. Very fortunate that you have a 3.2 crank. Must be nice to be that lucky. Lol.
From what I've gathered, you really don't want to go more than 98mm on the bore. So it'll put you up to 3.4L. Reason being, beyond 98mm, the forces are just too great for such little material that is left. Engines running more than 98mm bore are pretty strictly dedicated track cars and are broke down often. If I'm wrong here, somebody correct me but that is how I understand it.

2ndly, great read. I'm in a similar boat with my '82 911 SC. I'm slowly coming to the realization that I VERY likely will be splitting my case.

[thetorch]

Circling back with an update.

The main issue was as suspected the valve guides were terribly worn, more on the intake than exhaust. Some had 0.5mm of valve to guide clearance.

I did a full tear down. Short block now back together with:

• New ARP rod bolts
• New small end bushings on the rods. Small ends were within spec but on the high side.
• All big ends right on spec.
• New Clevite rod bearings.
• Crank journals all within spec.
• New crank and intermediate bearings.
• #8 bearing replaced. Was within spec (barely) but had a definite wobble when installed and a visible north/south wear mark.
• New Supertec head studs (ouch, those are costly).
• Through bolts heads, washers and nuts were ceramic coated.
• New case studs.
• New timing chains.
• New bushings on all rocker arms. 9 of 12 were outside wear limit.

Received new Mahle forged 98mm 9.8:1 P&Cs from EBS. Sold my 95mm cylinders for more than I would have thought.

Just waiting for my reconditioned heads.

Sealing the case was surprisingly easy...if you don't count the 2 weeks of cleaning parts. Seriously, this should be called the Engine Parts Cleaning Forum.

I was blocked from buying Brakleen for a week on Amazon because I hit some hidden volume limit.

[thetorch]

Update: She's back together as a 3.4L, and back on the road. 60 miles of break-in.

So far so good.

[Henry Schmidt]

Originally Posted by thetorch

Beautiful project, congrats.
Two thoughts:
I know it too late for this build but maybe it will help someone reading this post.
One of the great features of the Supertec head studs is the ability to install the piston/cylinder combination without dealing with the studs. Sliding the cylinders over the studs, then fighting with the clips can be maddening. You have easier access pin install and clips. It's generally good for 1.5 to 2 hrs of assembly time and less chance of losing a clip in the engine. [bing....oh shyt! where did that clip go?"






My second thought is an easy one. It looks like you could move the clutch lever one full spline. If you can get the lever past zero fulcrum ( the center line) you'll fine that the clutch will release much smoother.
If you can, remove the cable spacer and rotate the lever one tooth.

[thetorch]

Henry,
Thanks for those tips. I read on another thread about the ability to put the studs on after the cylinders, but only after I installed things. I did not find putting the wrist pin clips in difficult at all using the Stomski tool, so no big deal.

I have the clutch arm at 90 degrees -- though the photo skews the view of that. I will see if I have enough threads to get one more spline to the rear (I assume you mean that direction?) and see if I notice the difference. She releases very smooth now, so this will be an interesting test.

By the way I went with your suggestions on the monster sealing thread (except I prefer Hondabond 4 on any paper gaskets other than the valve covers, which of course get no sealant) and so far not a leak to be found. Fingers crossed!

C

[Henry Schmidt]

Originally Posted by thetorch

Henry,
Thanks for those tips. I read on another thread about the ability to put the studs on after the cylinders, but only after I installed things. I did not find putting the wrist pin clips in difficult at all using the Stomski tool, so no big deal.

I have the clutch arm at 90 degrees -- though the photo skews the view of that. I will see if I have enough threads to get one more spline to the rear (I assume you mean that direction?) and see if I notice the difference. She releases very smooth now, so this will be an interesting test.

By the way I went with your suggestions on the monster sealing thread (except I prefer Hondabond 4 on any paper gaskets other than the valve covers, which of course get no sealant) and so far not a leak to be found. Fingers crossed!

C

We also use a version of the Stromski tool but you have to be careful. The JE clips are larger than the Mahle clips used to design the Stromski tool. This tool was distorting the clips and leading the engine [clip engagement] issues.

Hondabond is made by Threebond so the product are the same. Using it on paper gaskets sounds reasonable. There is no "right" was just proven suggestions.

[Cevan]

Originally Posted by Henry Schmidt

One of the great features of the Supertec head studs is the ability to install the piston/cylinder combination without dealing with the studs. Sliding the cylinders over the studs, then fighting with the clips can be maddening. You have easier access pin install and clips. It's generally good for 1.5 to 2 hrs of assembly time and less chance of losing a clip in the engine. [bing....oh shyt! where did that clip go?"

Can you explain this? I presume you mean install the P/C to the rod and then install the head studs?

Thanks.

[PeteKz]

Since Henry hasn't replied yet, let me try:
1. Assemble the case, but leave the head studs off.
2. Put the pistons and rings into the cylinders, but leave them out enough to access the wrist pins and circlips.
HINT: count and lay out the circlips and base gaskets before you start this part, so that you don't have anything "left over" and wondering whether you put all the circlips in the pistons!
3. Put one circlip in the "away" side of the piston.(and don't forget the base gasket on the cylinder bottom)
4. Line up the piston and connecting rod and insert the wrist pins, then install the "close" circlip.
5. Push the cylinder into the case bore.
6. Loosely install one head stud and nut or holder to keep the cylinder in place
7+. Repeat for the next cylinder, etc.

If you do it this way, you can lay the piston/cylinder off to the side of the case bore where you have more room to work and are less likely to drop or sproing! a circlip into the case. You can also stuff a rag into the case bore to prevent it from going in there.

After you have all the pistons installed and cylinders pressed into their bores, then install the head studs permanently.