Cracked cylinder

[83930]

I need some info. I have cracked a cylinder for the second time in 16k miles. The engine is a 3.4 with 8.5 comp and 964 cams, running .8 bar boost and a stock intercooler. Will a fuel management system help stop the damage? I think it is going lean during acceleration. It has a ox sensor and freq valve. Do you think I should go back to 3.3 stock p/c set and 7:1 comp? I think that porsche did their homework on the amount of material the cylinders need to take the boost.Any Ideas would be greatly appreciated.I was told (by a so-called Porsche expert)that this combination would be reliable and dependable,and if I kept the stock boost of .8 bar I would have no problems. I'm getting too old to do an engine transplant everytime I take the car for a spin...
Thanks for any insight Guys.

Neil

[TimT]

You should get a EGT to monitor your exhaust tenps, this will indicate lean conditions.. Im not sure if the 83 930 has CIS, but if its is a CIS engine you can trigger the cold start valve while under boost. This acts like a 7th injector giving more fuel.

[Wayne 962]

Yes, the newer EFIs would help to solve this problem. Specifically, they can monitor the cylinders (with a knock sensor), and adjust the boost (variable boost) accordingly. I've got a whole section on this in my new engine book. The EFI systems are really the way to go to get the most HP out of a Turbo (with a variable boost valve).

With the feedback from the knock sensor, then you shouldn't have any problems with detonation - even if you get a batch of bad gas...

Porsche didn't have these systems when the car was designed 30 years ago...

-Wayne