High Compression Ratio ----> Detonation

[oldeskewltoy]

12 to 1 compression on a stock ECU = detonation.

BTW I think you may have MORE than 12 to 1!!! Your head is shaved .6, block .1, headgasket difference .4 just these calculations equal 1.1 on the CR for a 4AG... Wiseco has a BROAD range they set for 4AG pistons... it could be anywhere from 10.2 - 11.8!!! Add in the 1.1 and in worst case scenerio you are running CLOSE to 13 to 1!!!!! Have you done ANY combustion chamber mods? If not figure closer to their higher figure


WHOOPS... didn't see your last post. Ok, keeping the compression... can you at least do a static compression test for us??? We can back calculate your CR(approximately) from the engines actual compression test. If it isn't TOO high... a good engine management system(prices are ALL over for these....) should be able to adjust timing enough to use a high compression set up. If you are at 12 to 1+... You need a lot more duration cams then the 264 offer.... say a minimum of 280, but maybe closer to 288.