teke184

iTrader: (5)

is there a benefit to one head over the other:

- both heads flow the same cfm
- both have the same intake runner (and exhaust for that matter) volume

one head is milled to 59cc

one head has the chamber design for 59cc

*assuming both allow for proper PTV clearance**

GuitsBoy

iTrader: (4)

P to V clearance is the big one. And milling too much starts to impact flow. Shouldn't really be noticeable unless to mill quite a bit.

radkon

iTrader: (2)

+ 1 if they both flow the same then P 2 V is the only concern. If they are the same (tough in this situation) head and one is milled then flow is affected.

teke184

iTrader: (5)

gotcha...thanks.

i hear terms like "quench" and "shrouding the valves"....or was it the plug?

wondering how those thing played into the mix.

TARZAN

iTrader: (12)

What was it milled down from?

-Will

teke184

iTrader: (5)

what was WHAT milled down from??

these are hypothetical heads that i'm talking about.

but i was referenceing milling 241s down (and in conjunction with the gasket) making a 59cc chamber....like that of the 5.3L heads

GuitsBoy

iTrader: (4)

quench is changed via gasket thickness or piston out of hole height, not milling.

ssheets

iTrader: (1)

Wouldn't valvetrain geometry be the other thing that is affected?

I.E. a 5.3 head has the same valvetrain geometry as a 5.7 head, but the chamber ceiling is .030 (or .035") lower. (the 5.3s have smaller intake valves). So in rough theory, you can mill a 5.7 head and have the same cc that a 5.3 head has, but now your valvetrain is closer to your cam so your pushrod length will have to be changed. Your intake port to intake manifold will change accordingly too.

That's my 02 cents

radkon

iTrader: (2)

You are right, at a minimum you'll need shorter pushrods. The (new) gaskets on the intake should be able to accommodate the change.