Head shave question.

-

oldmodlover

Well-Known Member
Joined
Oct 17, 2015
Messages
438
Reaction score
267
Location
Concord. North Clackalaky
Bought a "machine shop fresh head." I know it has been cut but l have no idea as to how much. It is a drool tube head. I was told it was done 25-30 years ago so no known knowledge nor paperwork exists of work done that l know of.
Is there any way to tell approximately how much it has been cut?
I can CC it but have not done so as of yet.

Is there any correlation as to amount of cut ie: 10 thou, 40thou, 80 thou. To CC?
Like as in 10 thou = X amount of CC
60 thou = X amount of CC

Combustion chamber has been smoothed a bit.
I need to pop the valves to see if any bowl work has been done.
Just looking for ideas before setting aside time / money to have ( or not have) any more taken off.
 
Bought a "machine shop fresh head." I know it has been cut but l have no idea as to how much. It is a drool tube head. I was told it was done 25-30 years ago so no known knowledge nor paperwork exists of work done that l know of.
Is there any way to tell approximately how much it has been cut?
I can CC it but have not done so as of yet.

Is there any correlation as to amount of cut ie: 10 thou, 40thou, 80 thou. To CC?
Like as in 10 thou = X amount of CC
60 thou = X amount of CC

Combustion chamber has been smoothed a bit.
I need to pop the valves to see if any bowl work has been done.
Just looking for ideas before setting aside time / money to have ( or not have) any more taken off.

I think there is. If there is any basis for measurement, @Charrlie_S might know. I tagged him so maybe he'll chime in.
 
Nominal measurement between the head surface, and the rocker cover surface (by my measurements of many heads) is 3.605
To change CC's, mill .0066 for 1 cc
 
That is a "nominal" measurement. It does vary somewhat due to manufacturing tolerances. CC the chambers to verify the CR, since the chambers have been polished, and a valve job done.
 
Look at the small coolant tube that goes to the water pump. If it's level with the head surface then the head has been cut. Most folks would cut .090 to .1 without much thought. The coolant tube is like a go no go on the cut. Also if the lower row of manifold studs are out, it has been milled. You will still need to CC to tell what your chambers are at.
Here is a no deck cut:
IMG_0065.JPG


Deck cut:
IMG_0066.JPG
 
Here is a chart for different combustion chambers design and how many thousands for one cc

Screenshot_20200418-105956_Samsung Internet.jpg
 
.100 cut two slant heads from stock 45CC both times Stock heads I used a ML syringe vasoline and the top of a cd case, made i small hole on one end for air bubbles to escape and a bigger hole at the other end for the syringe to fit, used green coolant. Easy and cheap
 
-
Back
Top