Carb CFM recommendations

318willrun said

Way too much science. Gets in the way of a good build every time. I tune by letting the car decide and not a calculator, but that's just me. In your case it doesn't matter, because you just want a good driver and performance isn't your concern. I'm very familiar with your altitude. I used to live in Wellington and for years and years I have/had family in Loveland. My brother had a 850 DP on a mild 340 and never lost a race out there (Big block, small block, didn't matter).

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I get it. But at the end of the day you cannot defy the laws of physics, because physics does not care if you agree. If you simply ignore science, you will get to learn the hard way. I am not a fan of wasting money because I guessed.

I am not saying that cfm calculators are perfect. If they were, I never would have bothered asking. But they are still written by automotive engineers based on sound science and decades of engineering experience. I am not going to live and die by them, but I also am not going to ignore them.

I absolutely am concerned about performance. In no way does the fact that I am not drag racing mean I do not care about performance. There are many different measures of performance. I do not care about boiling tires or redlining at 6,500 rpms. But in between, I want this engine to run as well as it possibly can. Because if I do step on the gas, I want it to respond instantly and strongly. Just because the majority of driving will be mild, does not mean the engine does not need to perform when asked. Oversized carbs kill low end throttle response. It is unavoidable. There is no jet combination you can install to make the wrong carb perform properly on an engine. I may not be an expert, but I know enough to acknowledge that fact.

I appreciate everyone's input. I am not saying anyone is wrong - not at all. I got some amazing advice on this thread, and an amazing amount of disagreement among that advice. Bottom line is this definitely confirmed which way I will go. And I am more than confident it will work GREAT!