Econo Modified

[SSDiv6]

Originally Posted by randy wilson

Just curious. Why the 10 degree valve angle on the Ford, and the 15 degree valve angle on the Mopar? Thought they were 20 degree, and 18 degree respectively. I believe the vortec bowtie is still 23 degree.

Both approved cylinder heads are for circle track applications, over the counter with a OEM part number just like the Chevy Bow Tie Vortec head. Also allowed in the Chevy applications, although available in trucks only, is the cast iron LS-1 cylinder head.

On the W2 heads, there is a 18 degree for the OEM block and the 15 degree, which requires the Mopar racing block with the 48 degree lifter angle.

Although the Bow Tie Vortec head retains the 23 degree valve angle, the head version being used is the large port with 235cc intake volume as cast.

The N351 and W2 heads have as cast smaller volumes. However, the latest version of the 15 degree W2 head was redesigned and I have seen a cylinder head with a 2.08" intake and blended bowl with no additional porting flow 310 CFM @ 0.700" with a 190cc intake port.

Based on the performance of Michael Mans when he raced in SS/CS with the Bow Tie Vortec head, I believe a well built Chevy engine with the Pro Action head and even with the cast iron LS-1 head is capable to run in the 8's at the right track.