Cylinder Heads 101

64ragtop said

I realize that unskilled hogging out passages can result in worse performance, not to mention the possibility of digging into water passages, etc. The info on shrouding valves using oversize valves on relatively smaller bores was new, but easy to grasp. What I'm wondering is how much difference would a gentle smoothing/polishing of the ports, and matching the ports in the head and manifold or header to the gasket make? That is to ask is such gentle work worth the time and effort for a street motor just looking for a bit of improvement, but not worried about giant numbers???

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Mr.64, What you have asked about the smoothing and the gasket matching. First DON"T SMOOTH THE PORTS, leave them as rough as you can as this helps atomization and doesn't hurt flow. Actually super flow says it has no effect on flow, but smoothing the ports will cause the fuel to puddle and cling on the port walls on the intake side. Causing a rich condition in the engine. But gasket matching and doing a good bowl blending will pick up the air flow greatly and HP, this will give you 80-85% of a fully ported head when done properly with a good valve job. So yes it's well worth it.


BJR Racing