Milled G head


http://209.208.111.198/Topic65684.aspx 		Print Topic | Close Window

By ramair - 14 Years Ago
I just picked up a set of ECZ-G heads, does anyone know of a measurement I can take to see if they've been milled? It looks like thay may be virgins but I need to make sure..   Thanks..
By ramair - 14 Years Ago
Ok I guess I should have searched the forum 1st before asking, I see that the rectangular blocks on the exaust need to be 1.00in. .A quick and inaccurate reading with a tape measure looks like a bit under the 1.00. I'll remeasure with a caliper on Monday...Not real sure if its a posted head or not but how much is too much?
By Oldmics - 14 Years Ago
I dont know how far is too far,but I do know that .060 cuts were acceptable.

Oldmics

By Rono - 14 Years Ago
I'm not sure what the maximum you can mill the heads is either. I think the minimum you want to be at when it's all said and done is 1.000" measured at those rectangular bosses. I have a set of "G" heads that were 1.025 when I started and I milled just enough to make sure they were flat across the face and that was 0.007". On the 471 heads I have, I started with the heads at about 1.010 and milled about 0.008" to get them flat, so I will be checking valve clearance when the short block is done. I think you also have to consider your cam lift when figuring how much to mill. I would be conservative and just mill enough to get the head surface flat.

Rono

By 46yblock - 14 Years Ago
The basis for milling I am familiar with calls for max. mill of .025 on unposted heads.  Block decking past or planned also needs to be taken into account, as the sum of block decking and head milling, minus the extra thickness of composite gaskets compared to steel gaskets, may require the milling of head intake flanges to achieve proper intake fitment. 

I milled my posted 113 heads approx. .030, decked .028, and had to have intake flanges cut I think .045.

Mic-ing the blocks on the side of the heads is a gauge only of past work.  I have found the thicknesses to be all over the place, even on one head.  CC'ing the chambers can also aid in the estimate of previous work.