CLASS RACER FORUM - View Single Post - 335 HP 396 290 Head Casting Build & Dyno Test

HP HUNTER · 05-23-2024, 07:28 PM

OK- the valve job is 30/45/60/75/90 on a BBC production head the valve bowl is too big to get much if any 60 degree angle with a 2.065 valve. In the picture you will see the lap line, below the lap line is the 60 degree angle which is around .180 wide, that 60 degree angle is partially responsible for the low lift flow gains. If you look at the picture before modifications you will see there is very little 60 degree angle below the 45 degree seat. Hope that explains it.

05-23-2024, 07:28 PM	#22
HP HUNTER Senior Member Join Date: Feb 2012 Location: Colorado Springs Colorado/Thousand Oaks Ca Posts: 656 Likes: 82 Liked 371 Times in 129 Posts	Re: 335 HP 396 290 Head Casting Build & Dyno Test OK- the valve job is 30/45/60/75/90 on a BBC production head the valve bowl is too big to get much if any 60 degree angle with a 2.065 valve. In the picture you will see the lap line, below the lap line is the 60 degree angle which is around .180 wide, that 60 degree angle is partially responsible for the low lift flow gains. If you look at the picture before modifications you will see there is very little 60 degree angle below the 45 degree seat. Hope that explains it.