Reply to "Blue Thunder intake manifold porting"

The much-discussed 'poor distribution' of corner cylinders vs center cylinders in V-8s is the subject of a current Hot Rod magazine article. They dyno-tested Comp Cam's new 4-lobe camshaft grind with 2-3 more degrees of intake lobe separation on the corner lobes relative to centers, ala NASCAR cams. The intake flow balance was substantially corrected; on a 500-horse dyno-mule, they got 9 more horses- for the cost of a hydraulic roller cam, short-travel roller lifters and beehive springs. They also got 7700 rpms out of the special hydraulic roller cam. To my way of thinking, the extra 2% power is hardly worth the trouble unless you're racing for money in a restrictive class. The extra rpms probably came as much from the short travel roller lifters and beehive springs as anything, but I could be wrong.

If you still want to see if it's worth the trouble, another cheaper, simpler way NASCAR tuners use to balance intake flow is with 1.80:1 ratio roller rockers on only the corner cylinder intake valves. This gives the same extra 2+ degrees of lobe sep plus a tiny bit of extra lift, without changing cams. Harland Sharp makes both 1.73:1 and 1.80:1 street roller rockers for a 351-C. Single rockers are about $25 each and if you already have a set, you only need 4 more to do this experiment. Let us know how it all works out, please.