Hey guys here is my dilemma, I am currently building a boosted b17. I plan on running around 15psi. My problem is that i got the engine from a friend that used it in his all motor car. The engine had already been sleeved and bored to 85mm. I went ahead and bought 85mm 9.5-1 CPs. We took to the machine shop to have it looked over and he said that the piston to wall clearance is already at 4.5 thousands and CP recommends running 3 thousands. The machinist also said that the cylinder wall were also a little out of round and they needed a light hone. That would put me at 5 thousands. I read the Jeff Evans article and he said he runs 4 thousands for piston expansion. My question is has anybody ever built a turbo motor with clearances this large. I know the thing would sound like a kitten until it warmed up but do you guys think there would be any problems. Thanks for the help and info

 

my first build i had that same problem but I wasnt at 85 I was at stock bore and **** .... with srp pistons the motor sounded like it had a valve hitting a piston even when warm ,, oil was going out to the intake manifold bc the piston were way too small for the bore of the slevees

 

yeah thats what im afraid of. This is going to be a street car and i dont want it burning oil like crazy

 

anyone else?

 

man guys 58 views and no one else has anything to say about it?