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Old 09-01-2012, 10:50 AM
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patrickt patrickt is offline
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Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
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Quote:
Originally Posted by Grubby View Post
Starting from square 1 he would have suggested a 750 double pumper. His opinion is that with about $175 in tuning work my carb will be very close in performance to a 750 double pumper.

I am going to give him a shot.

He says the 850 would not be as responsive for a street car, and the 750 does give up some max HP.
John, I discussed this same issue, at length, with the builder when I was having my engine spec'd and assembled. In one sentence, his opinion (which I will just pass on without editorial comment): Dual fours would have the most horsepower (but a TP won't fit over them), a larger CFM single that is greater than the 750 would have the second highest horsepower, but the 750 would feel more responsive, quicker, and more fun on the street. As between vac secondaries and mechanical secondaries, properly tuned vac secondaries were superior in non-race conditions, and when tuned properly, a second accelerator pump was not necessary. Now, mind you, dollars were not an issue on the carb choice. We talked it over, and that's what he thought was best. My engine, with the shorter 4.125 stroke, light pistons, light aluminum flywheel, solid flat tappet, was all meant to be a fun "quick-revver," and that was his considered opinion on the carb. If he had said, "I really recommend the blah-blah carb, but that's an additional $500..." I wouldn't have batted an eye, and he knew that.
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