420hp 454 questions
#11
Registered
![Default](/forums/images/icons/icon1.gif)
I believe the reason dart gives those specs of maximum flat mill cc's, is for the reasons you mentioned. And why I said some heads can be milled more than others. Not all the same .
On afr's site, on the 325cc head , the chamber is 117 as cast, and 121 CNC ported. Their spec is .006 per cc . maximum flat mill to 108cc for as cast chamber , and 114 for CNC chamber. Angle mill, .009 per cc to 104cc for as cast or CNC chamber.
Last edited by MILD THUNDER; 03-15-2015 at 08:02 AM.
#12
![Default](/forums/images/icons/icon1.gif)
My dart race series aluminum heads have been flat milled a lot. The intake valve seat edges have been cut into, but not enough do damage the actual sealing of the valve. This is with a 2.25 intake valve. No PTV clearance issues with a 236/245 630 lift 114 hyd roller. With a flat top JE piston that is
I believe the reason dart gives those specs of maximum flat mill cc's, is for the reasons you mentioned. And why I said some heads can be milled more than others. Not all the same .
On afr's site, on the 325cc head , the chamber is 117 as cast, and 121 CNC ported. Their spec is .006 per cc . maximum flat mill to 108cc for as cast chamber , and 114 for CNC chamber. Angle mill, .009 per cc to 104cc for as cast or CNC chamber.
I believe the reason dart gives those specs of maximum flat mill cc's, is for the reasons you mentioned. And why I said some heads can be milled more than others. Not all the same .
On afr's site, on the 325cc head , the chamber is 117 as cast, and 121 CNC ported. Their spec is .006 per cc . maximum flat mill to 108cc for as cast chamber , and 114 for CNC chamber. Angle mill, .009 per cc to 104cc for as cast or CNC chamber.
Last edited by GPM; 03-15-2015 at 12:56 PM.