What are the effects of milling a head? Can a 76cc head just be milled to 64cc? Thanks guys

Matt

 

you would have to take roughly 070-080" off to achieve a 12cc drop in chamber size. not a good idea!!

 

I think with milling you are only supposed to do it to gain a little compression, not a whole lot. I don't know exactly how much, but that is too much.

 

I posted this a while back, and got a lot of awesome info about it....not sure if the search is working yet though.

basically you dont want to mill heads to gain compression, you mill heads to get a true surface.

if you want a higher compression ratio, you should go with a smaller chamber head.

i chose 081 305 heads, ported and polished with 1.94 intake valves. they are 58cc

good luck

 

Where did you get them from? How much did they cost you and what machine work is needed to run say a XE 272 cam? Thanks

 

i bought them off a guy for $25 in good shape. they are really common so they arent that expensive. All the machine work im having done is a valve job for the bigger intake valves and screw in studs.

Sittingbull has a link at the end of his sig that tells you everything you need to know about porting them. people have flow tests proving that they will out flow vortec heads. thats would sold me on them.

 

You can safely mill a factory 76cc head to 64cc by "angle milling" them. But that costs lots of extra money.
Like stated above its better/ cheaper to start out with a 305 head and enlarge the valves and unshroud the smaller chamber
and then port them to get the head you want.

look for 416 or 081 castings and sell off your old 76cc heads.