FYI on using 91 P&C on pre 91 3.3
 

As part of my rebuild, I purchased a set of the 91-92 fully finned P&C kits that were on ebay (the seller is local to me so I picked them up).

First, the engine tin needed to be trimmed a bit in order to fit as close to the cylinders as it did on the stock cylinders. Even though it may fit w/o trimming, Id expect that they were designed to work at a specific distance from the cylinder, so I trimmed them to maintain this distance.

But, the REAL problem surfaced when I was completing final assembly - I turned the motor over by hand a few revolutions to make sure all was OK, and I started to pat myself on the back as Inoticed how smooth and easy it turned over. I quickly realized that even 7:1 will have noticable compression, and I had a big problem. :mad:
The 91 cylinders have a 2.5mm lip on the top that seats in the head. Unfortunately, the 87 heads have a corresponding 3mm deep seat - the stock 87 cylinders have a 3mm lip. 0.5mm of 'open space' doesn't do well for maintaining compression, so the motor is back apart for the ~$7 0.5mm sealing rings on the 91-92 motor.

I did ask questions about using these and this never came up, but it's still phooey on me for not measuring things. A search of several lists' archieves resulted in one post from 2004 or so with a similar issue, but again for some reason the searches I did before I assembled the motor didn't reveal this issue.

Hopefully any others who bought these will not do the double assembly I'm into now......

Pat K
87 930

Don't feel so bad... The first time I installed the C2 turbo cylinders I didn't know about the o-ring that goes at the base of the cylinder...

I got the engine assembled, was happy, fired it up, and it leaked like crazy. I had to pull it all back apart just to install those o-rings....

Brian

And yes, the original tin fits without modification...

I did get the o-rings in there the first time.... I should be receiving the sealing rings today, so maybe over the holiday weekend I can get the motor back together.

Pat K
87 930

the good news is you don't need to separate the heads from the cam towers. Just turn the engine over to TDC and remove the head stud nuts.

Brian

That is exactly what I've done....

The 3.3L C2T's use a 0.5mm head sealing gasket. That's what I use in my build. It provides better sealing at higher boost pressures <= 1.4bar.

Any pics guys ?