CLASS RACER FORUM - View Single Post

R. Thorne · 12-12-2012, 12:10 PM

Updating some heads to the "new 2009" rules. 1. "any valve job" Does this mean oem valve seat angle no longer applies (go from oem 30 degrees to 45 degrees or oem 45 degrees to 58 degrees?) ? 2. "bowl hawging" will pass tech as long as it is centered off the valve guide? 3. back cutting valves is ok? 4. Has runner volume been changed to account for these modifications (additional 2-3 cc's )? 5. Can heat riser ports be filled? ( "heat riser passage may be blocked from intake manifold side of cylinder head. Blocking passage down in valve pocket prohibited.") Thanks, Ron.

12-12-2012, 12:10 PM	#1
R. Thorne Member Join Date: May 2009 Posts: 182 Likes: 64 Liked 100 Times in 33 Posts	stocker cylinder heads Updating some heads to the "new 2009" rules. 1. "any valve job" Does this mean oem valve seat angle no longer applies (go from oem 30 degrees to 45 degrees or oem 45 degrees to 58 degrees?) ? 2. "bowl hawging" will pass tech as long as it is centered off the valve guide? 3. back cutting valves is ok? 4. Has runner volume been changed to account for these modifications (additional 2-3 cc's )? 5. Can heat riser ports be filled? ( "heat riser passage may be blocked from intake manifold side of cylinder head. Blocking passage down in valve pocket prohibited.") Thanks, Ron.