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View Full Version : SBC Squench area reshaping. And detonation elimination. HOW!



LowBuckX
08-18-2005, 11:09 PM
Just reading through some books and found some interesting stuff in the Bill Grumpy Jenkins book about tunning the quench area on the SBC head. Ive always heard and believed that you should leave it alone and leave the ledge sharp.
But In Bills book he outlines some mods that he does. One was to radius the ledge on the exhaust side to help with swirl and exhaust flow.
Would something like this also help in eliminating detonation on a street motor. Im planning a 400 build to run on cheap pump gas with a HP goal of 475 on the motor(86 octane) and am looking for all the little tricks i can find to do so. Thanks.

WELTERRACER
08-20-2005, 04:25 PM
I had a 355 with 305 heads on it.... i had rounded the edges of the combustion chamber on that to keep from detonation... as the 305 heads on had 54cc chambers (they had been plained several times)

I dont think you should have a problem making 475 hp with a 400... a really good set of aluminum heads... a fairly large roller cam and 9.5-1 or 10-1 compression, a JR victor or Airgap intake and a 850 double pumper(stick) or 850 vacume secondary (automatic)

cantstopit
08-21-2005, 07:43 PM
not sure on your specific question,as I don't think it will really make a difference, I would definelty look into all the different type of coating, as those make a measurable diffence in detonation. Also look into David Vizard, as he is always doing new things