robertfrank

iTrader: (27)

Ok so I have another question, which I'm sure I'm driving everyone batty at this point lol.

Anyways, we all know that swapping to a gen 3 aluminum head produces stupid high compression.Well, has anyone here modified the gen 3 chambers to allow for lower compression? In my mind that would be an easy thing to do of you have the skill. Looking at alot of these heads there is a TON of material and shaping that can be removed and cleaned up to gain chamber cc's.

Any thoughts?

Six_Shooter

iTrader: (2)

You won't be able to remove enough material and leve enough to have the strength needed to make any noticeable difference in compression without also compromising what makes the chambers so good.

So much easier to swap pistons.

robertfrank

iTrader: (27)

Strength? As in? The way I see it, measure out what cc's the iron heads have stock then measure out what your set of aluminum heads have. Scribe out the bore size using the head gasket of choice and open it up to as close as the iron head cc as possible while still promoting good quench and swirl. Sure the end result would probably still be a touch high but well within reasonable pump gas range.

Six_Shooter

iTrader: (2)

Strength, as in ability to hold the shape, especially under the high pressures of internal combustion.

By the time you do that you've destroyed that gen3 head. Not only will you very likely break through to the cooling passage but you'll then be going to a very poor gen1 combustion chamber design.

The shape of the gen3 combustion is a very large part of what makes them work so well. So you'll not be able to open up the combustion chamber as much as you want while still keeping that good swirl and quench...

1slow8t3

When I did my aluminum heads on one of my builds, after cleaning up the chambers properly it dropped my CR around .3-.4. Removing any more and you are messing with the flow and the amount of meat you have left.

robertfrank

iTrader: (27)

What heads were you using?

1slow8t3

3400 heads.