Piston cut outs?

[MPO]

Piston cut outs?

Interesting one…

Do we need piston cut outs because of bigger valve diameters (Big Valve Heads) and/or to allow for increased cam lift?


MPO

[macdeb]

Sort of both and for cam duration.

[MPO]

macdeb said:

Sort of both and for cam duration.

so, do all 400 HC's and 4.3's have piston cut outs?

There were some 4.3's that didn't have Big Valves but did these ones have large enough cams to justify the cut outs?


MPO

[carsy]

All 4.3`s have the cut outs. Big valve or not.

[Sardonicus]

macdeb said:

Sort of both and for cam duration.

< This, the 4.0 HC has the eyebrows but runs stock RV8 valve sizes

[MPO]

So, with two piston cut outs per cylinder what increase on cc are we looking at?

MPO

[Boosted LS1]

A cc per cut out appx, maybe a little more but I doubt it'll be very much.

[Sardonicus]

Boosted LS1 said:

A cc per cut out appx, maybe a little more but I doubt it'll be very much.

Yeh I would estimate 2-3cc per pot