Need advice: WTB boost motor...will this work?
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From: Birmingham, AL
Need advice: WTB boost motor...will this work? A friend of mine has a SDPC Aluminum 402 with flat top pistons, a big cam which I know will need to be changed, and Trickflow heads with 65cc chambers. Apparently this all calculates to 11:1 compression. If I put a set of heads with bigger chambers on it, will that lower the compression enough to be able to use this for boost? Also, do I need an iron block or does it really matter? I just need to hear from someone who knows a little more about it than me. I was told dished pistons would help with the shape of the flame and other stuff. It's a damn good deal on the motor and even if I did have to change pistons I think it'd still be worth it. 
Last edited by WS6 GreeN; May 3, 2012 at 10:59 AM.
Yes it will work. Change that cam to a more turbo friendly cam. Install a set of 317 truck heads to get the CR down to 9.5:1 - 10:1. Leave the flat top pistons alone. The 9.5:1 - 10:1 CR will help spool time and will give the car more throttle response when your out of boost.
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From: Norn Iron
Of more importance is piston design. If the piston is a strict n/a design, the top ring could be placed very high which is far from ideal for a boosted engine of any kind.
Flat top or dished is much less of a concern.
Flat top or dished is much less of a concern.
