5.0stang

iTrader: (1)

What is the most you can mill the LT1 cylinder heads?

Are all the combustion chamber volumes the same through the years?

Thanks!

5.0stang

iTrader: (1)

Bump........

fuzchunk

54cc &ten thou .010 by the book, actual results may differ

96capricemgr

iTrader: (1)

What are you trying to accomplish?

I know from experiance that they can go to at least a little over .030, problem is this screws you down the road and you try to build a motor and want to use a flatop with good quench, not the chamber is too small to get the right compression.

96slow6

Also as a side note. I to have seen upto .030 but with the impy gasket you need to deepen the alignment plug holes.

mean94lt1

iTrader: (34)

mine are .014 so i know you can go that far

96slow6

Did your block alignment pins fit into the head ok? If so there is a good general reference. @ .014 they do not need to be machined deeper.

CamaroKid89RS

iTrader: (2)

I had mine milled like .018 or .019 when I blew my head gasket so I know you can go that far.

9formula4

iTrader: (5)

im going .010" with mine.

The combustion chambers will get smaller.

foggedz

iTrader: (1)

Mine have been milled some where in .035 - .04 range. The intake also had to be milled to get the ports to line up.

96capricemgr

iTrader: (1)

That is a very good point to make, start cutting heads this much and the intake can not only be missaligned but the intake can bottom out on the ends of the block and not seal properly.

5.0stang

iTrader: (1)

I was just curious how much they could be milled.

By shaving it down .03-.04, what kind of effects does this have on the given compression?

Thanks for the replies thus far!

96capricemgr

iTrader: (1)

If looking for compression start at the gasket. The stocker is .049 and there are readily available reliable and inexpensive options down to .026. which is like .5 compression gain in gasket alone.

speed_demon24

iTrader: (6)

Not sure how much mine are milled, but the intake surface is milled to compensate for that + the head gaskets. Then I had to mill the end rails on the intake manifold since they were bottoming out on the block.

C_Rules

iTrader: (7)

just curious how much do you have to mill to lose 1 cc? is there a ratio?

5.0stang

iTrader: (1)

Quick question, do the LT4 heads need the LT4 intake to match, or will the LT1 intake work?

96capricemgr

iTrader: (1)

The LT4 intake is internally the same as the late LT1 intakes but it has more material above the port to seal to the taller ports in the LT4 heads.
GIZMO posted this pic some time ago and it should help you understand.
http://i85.photobucket.com/albums/k5...1/DCP_1456.jpg

That said the LT4 heads are NOT a particularly good idea unless you are just after being able to say you have them to impress the ignorant.

IronOutlaw

iTrader: (4)

mine are milled somewhere around .080. apparently whoever owned the car before me blew a headgasket to and had them shaved extra for compression or someting.

blackz93

iTrader: (2)

I thought they were .049?

96capricemgr

iTrader: (1)

You are right, I was thinking about the Felpro, which is .039, I will go back and edit for clarity, thank you.