Join Date: Sep 1999
Location: Vancouver, Washingon
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Re: CJ - REbuilding 304, advance the timing?
Ok, very good question. Quite often there is confusion between spark timing and valve train timing / camshaft timing. You seen to have a good idea that what your wanting to do is advance the valve train timing / camshaft timing. The short version explaination of advancing the valve train timing / camshaft timing will shift the torque and horsepower performance to a slightly lower RPM. For example if the 304 has the camshaft installed to factory specs, and for example the let's say the the max torque is 310 Ft. Lbs @ 3800 RPM's and max horsepower is 265 at 4200 RPM's. Then let's say for example the valve train timing / camshaft timing is adavanced by 4 degrees a typical shift in performance would have still have the max torque at 310 Ft. Lbs @ but lowered to 3500 RPM's and the max horsepower would still be 265 but lowered to 3900 RPM's. I'm not an expert with the AMC 304, I more a Chevy 350 expert. Quite often, I'll install a Chevy 350 camshaft plus 2 degrees for pickup engines that usually do towing or mild 4X4 off-road use.