Quote Originally Posted by rumrumm View Post
I have been watching this thread, and I have a question. I am not trying to start an argument with you, techinspector1, as you have considerably more experience than I have. But I don't quite understand your recommended cruise rpm for a cam with 230 degrees @ .050 duration. Perhaps you can explain that to me because I have achieved different result. My 383 has a 230 cam [CompCams 280 Magnum], AFR 190 heads [68cc chambers], flat top forged pistons w. 5cc relief, 6 inch connecting rods, and a zero-decked block with a .039 head gasket. That equates to 10.6:1 static compression, 8.44 dynamic compression. I know that is somewhat on the edge of what pump gas will accommodate. I had it run on an engine dyno to set timing and dial in the carburetor, and its best pull was 450 hp @ 5200 rpm/468 ft. lbs. of torque @ 4300 rpm. It made the most power with 32 degrees total. It runs fine on 92 octane pump gas, it will cruise all day in overdrive [700R4] at 2100-2200 rpm without ever dropping down a gear to climb a moderate hill. But if you get much too below 1800 rpm, it is going to want a lower gear. Is this because the engine makes so much torque and the vehicle is so light? This is in a '32 Ford coupe weighing around 2600 lbs.
As I have stated before, I lean on the manufacturers for actual information about what will work and what will not work. None of what I say comes out of my mind without verification. In the case of posting the cruise rpm for a 230 intake cam, I would refer to the Crane HR-230/352-2S1-8 IG, 108 LSA in the Crane catalog, where that cam is listed as needing 3000-3800 cruise rpm or the Crane HR-230/359-2S-12.90 IG, 112 LSA in the Crane catalog, where that cam is listed as needing 3600-4400 cruise rpm. I have no doubt that the cam you have in your motor should be operated at approximately the same cruise rpm. The fact that you are cruising it at 2100-2200 just means that you are out of the cams operational range and that you would get much better fuel mileage and throttle response with a cam that is designed to cruise at 2100-2200 rpm's.

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