If a set of heads were to flow 268 @ .600 lift what would they flow @.525 lift? and is it respectable? Thanks

 

impossible to tell...depends on how they were ported.

 

Have them flowed and you'll know for sure.

Oh, if you're using them with the hot cam, you'd probably be better off finding out what they flow at .450 and .500.

 

It would be different for most heads depending on a few things. Valve job, back cut on valve, shape of port, short side radius width and how much it was layed back.

Some things work well at some lifts while sacrificing flow in others. Usually .350 to .450 lift is the point at wich things will cross. Most things that work REAL well below this will sacrifice flow above this and most things that work REAL well above this will sacrifice flow below this point. You just look for the best compromise for flow in the area the valve will spend most of its time.

If properly done for a hydraulic roller (where the valve spends most of its time in the low and mid lift), the #'s should be in the 260 to 265 range. If the port is designed to flow well in the low and mid lift area, it will not pick up much CFM once you reach .500 to .550 lift or so.

The ONLY real way to know what YOUR heads flow at this lift would be to have them flow tested.

Lloyd Elliott
NightTrain66