Originally Posted by bear4333
what's the best compession ratio for a bbc 632 that would make the best power? I'm looking to purchase a short block, my heads are dart 360 cnc.
First are you ever going to run any power adders. if not, how often do who want to go into the motor, With nos we run 118 or even 123 and limit our c ratio to 14.2 If a straight motor deal would can go up to 16.5 to 17.1 but you will have to watch the timing, Now in bad air, or high altitudes you can run more timing, but if you are just going to bracket race, then build it with 14.5 and just have fun. Q-8 stuff is a whole different process, and your cost in the end will be higher. At 14.5 you can always add nos, now don't get me wrong you can add nos to about any motor, but nos works better at a lower CR, this is what we have found out on the motors we have and we do have 486 cubic smallblocks and three BB over 800 inches, and I do build motors for a living even though I'm retired. Hope this Helps