Thread: Just dynoed my 396 BBC...how to get more HP?

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if anything I'd guess your compression is on the high side... At 160, you have about 10.9:1 dynamic compression at sea level 70F... Probably putting your static cr north of 12:1... Do you know what the actual SCR is? You really should know these things in building a motor and picking a cam... Do you have any ping? Cr that high you probably want to use 110 octane or straight 100 at the very least... What heads? Iron or aluminum? My 402 had 540 lift and that required relief in the bore for the intake side with closed chamber heads so you probably can't go much higher on the lift but if your cr is as high as I think you want quite a bit more duration.... How can you get reasonable numbers out of desktop dyno if you don't even know your cr? Who built your motor?

Sorry if I'm ruffling any feathers but this don't add up

-Chris

160 PSI is not 10.9 dynamic compression. My engine would have blown up running 91 octane for the past 5 months. I can't remember who posted it, but I remember seeing something posted that anything less than about 185-190PSI was able to run on pump gas. The engine is right around 9:1 static compression which is a little low. I just wanted to confirm if that matched up with 160PSI. And I built the engine myself. Closed Chamber Oval port heads 96.4cc chamber with a piston that measures -1cc. Between the very small dome and the valve reliefs it is basically a flattop piston. There was no detenation detected on the dyno...