Compression ratio vs Porting

I know this is taking this subject of target a little BUT.......

C130 chief, i have to disagree.


My first sets of head that i ever ported, had more air flow, had the fuel to support it, and became a DOG on bottom end.

although i had a lot more cfm then before, i totally DESTROY the bottom end.

Did it make more Power! YOU BET, by a couple mile per hour at the end of the 1/4.

Did it run faster? NO! A full sec Slower!!! Why? Because even though it would rev 1000 rpm higher now.(6800+) it would not get out of its on way! It was dead for the first 60 to 100 foot of the track..........then...... it took off like i hit it with a shot of nos!

A eng is a air pump..........and so much more then that. I had such bad exh reversion, the the intake manifold was black all the way up to the carb base.

And that was with a 9.4 compression 340 .474/280 MP cam.

Yes more air/fuel will make more power, IF the port is not to large(read air too slow or weak velocity) and the exh doesn't have reversion or exh reverting to the intake.

Bigger isnt always better, the port has to have the correct size and shape for the CI and RPM. You can't correlate the first set of heads you ported with making you go slower. Its about the correct shape,size and combination, and that includes the cam, compression, etc. That's like claiming every engine needs "backpressure" to run right.