I’m upgrading to a dual pattern grind for my 1962 Chevy 261 rebuild. For background, this engine has a 848 head, Buick 455 springs, Bel Air Powerglide inlet valves, TRW 040-over forged pistons, an Offenhauser dual intake manifold and a C1 Corvette dual exhaust manifold. The backend has a 3.55:1 ring & pinion from Patrick’s. There’s also supposed to be a torque-tube converter for a Saginaw 4-speed from Patrick’s (paid over a year ago but still don’t have the product).
Goes into a 1950 ½ ton 3100 PU. The truck is a daily driver, no drag or track. About 80/20 highway/city, around 65 mph on the road. There’s some towing, but not heavy or long-haul.
I’ve drilled deeply into Inliners and other forums looking for cam recommendations, without much joy. Most posts are about single pattern grinds, with precious little about dual patterns. What there is (for Langdon’s proprietary “Bulldog”) doesn’t give enough grind specs, and understandably neither Langdon or Delta Cams will discuss.
My engine builder has recommended two grinds. The first has 244-3 lobe advertised duration (200@0.050) intake. The second has 252-7 lobe advertised duration (210@0.050) intake. Both I believe have 264 advertised durations (220@.050) exhaust, 0.435 intake and 0.440 exhaust lifts and 110 lobe separation. The second grind I think is very close to the Bulldog which has 254/264 advertised durations.
Ideally I’d like a smoothish idle, not too rumpy, with a power band suited to my application. Anyone care to weigh in on which you think is the better cam?
Thanks,
Mark
