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thumper64 · September 21st, 2018, 03:08 PM

In the world of CNC ported heads and such, I was hoping for measurements at different points, like below the valve seats, at the dividers... or something better than just "buy a dozen heads and swap it out over and over until you find how far to go before you ruin it". Why waste the time and money if someone has something that works and isn't afraid of sharing some insight? I know CFM isn't everything. A full on race ported head isn't going to perform right on a street motor that sees 3-8k RPM 99% of the time, and 14k RPM just that .1% of the time, or at least a similar situation with car cylinder heads where a head ported for a 1000hp dedicated race engine isn't going to work right on a 275-350hp street car. I could keep hogging a head out and then add modeling clay to see where I went too far, but again, a flow bench doesn't tell you everything.

September 21st, 2018, 03:08 PM	#9
thumper64 ninjette.org member Name: Tim Location: Quad Cities Join Date: Sep 2012 Motorcycle(s): Ninja 250 Posts: 102	In the world of CNC ported heads and such, I was hoping for measurements at different points, like below the valve seats, at the dividers... or something better than just "buy a dozen heads and swap it out over and over until you find how far to go before you ruin it". Why waste the time and money if someone has something that works and isn't afraid of sharing some insight? I know CFM isn't everything. A full on race ported head isn't going to perform right on a street motor that sees 3-8k RPM 99% of the time, and 14k RPM just that .1% of the time, or at least a similar situation with car cylinder heads where a head ported for a 1000hp dedicated race engine isn't going to work right on a 275-350hp street car. I could keep hogging a head out and then add modeling clay to see where I went too far, but again, a flow bench doesn't tell you everything. __________________________________________________ Motorcycle noob, feel free to ignore me.