Rebuilt/overhaul 3.6 engine - advice needed

[ischmitz]

It looks like I have the famous head to cylinder leak on my 91 3.6 engine with about 45k miles on it and it's time to address that. I am in the process of planning what else I should do while I am in there. I don't want to split the case. While I don't want to spend tons of money I still want to do it right. So a 3.8 conversion is probably out of question if the cylinders are still in spec. I would like some feedback from the group:

- Should I replace the rod bolts with ARP or Raceware. Which are better? It seems the Raceware are not stretch bolts while the ARP are. And it can be done through the spiggot holes, right?

- Should I replace the head studs with the 993 type, raceware, or ARP or leave them alone?

- Should I have the exhaust valve guides done only or both intake and exhaust?

- Should I replace the piston rings?

- I will use Walt at Competition Engineering to flycut the heads and the cylinders and to machine a groove so that I can use headgaskets?

- Tyson suggested to replace the O-rings on the case through bolts.

Anything I have forgotten,
Ingo

[Bill Verburg]

Should I replace the rod bolts with ARP or Raceware. Which are better? It seems the Raceware are not stretch bolts while the ARP are. And it can be done through the spiggot holes, right?

I don't think that you would go wrong w/ either. I've heard that they can be done w/o spliting the case but never talked to any one that did it.

- Should I replace the head studs with the 993 type, raceware, or ARP or leave them alone?

I replaced my 993s w/ the late Porsche black epoxy coated ones. They're both good choices for a relatively stock motor. Raceware or Arp seem like overkill for most of us along w/ Pauter/carillo rods.

Should I have the exhaust valve guides done only or both intake and exhaust?

I did all of mine, its relatively cheap, think about some larger valves and better valve train while you're in there. 993SS or GE60 cams would be a real nice option as well. There's a lot of power available in the heads w/ the right cams.

Should I replace the piston rings

Again cheap while the motor is apart.

You can easily get close to 300 honest hp w/ stock 3.6 pistons and careful headwork/cams/chip.

[alan911sc]

Are you sure Competiton Engineering could do something to the cylinders for the head gasket. I always thought they could machine the head and then you had to get the newer style cylinders that accept the head gasket. If they could machine the cylinder some how it sure would be a less expensive alternative to new cylinders.

[ischmitz]

I talked to Walt several times. Really nice guy. Yes, he can machine the cylinders too so that I can re-use them if they are in spec.

Ingo

[alan911sc]

Not that my 1990 C4 has a leak, but that is good to know when rebuild time comes. Do you have a guessitmate for the cylinder and head machining. Just wondering for future planning purposes. PM me if you don't want to post the cost.

[schubee]

alan911sc,

I have my heads and p&c's at the machine shop as I write. I'll give you detailed info once they're done. It should be in a week or two.

[alan911sc]

Definitely will appreciate the feedback. Have a happy holiday season if I don't hear from till then.