Inputs on a home built 318 for red light to red light fun

RustyRatRod said
I'm not advocatin chevy. I like everything old and American, I like Mopar best. I just find it funny that every single American auto maker through the muscle car years did "something" in the engine department that was not conducive to making power more than the other make. With Chrysler, it was using open chambers on everything with no quench whatsoever, with Chevy they had quench heads and didn't use them, with Ford they ground their camshafts with retarded cam timing. It was like WTF were they all thinkin? Pontiac had some FINELY machined combustion chambers both open and closed, but again, didn't take advantage of quench. Even the 67 440HP engine with the 915 casting closed chamber heads didn't use them, because the pistons sat so far down in the hole. Only thing I can figure is, they were still learning.

What’s interesting is (comparing same era stuff) the SMB, with its higher rod ratio and near best spark plug location still only required 35 degrees of total timing, whereas a SBC with its lower rod ratio and absolutely garbage spark plug location needed (for a 327) about 40 total, for a 350 about 42 total and a 400 needed 44 plus degrees of total timing. And those were all “quench” cylinder heads.

The upshot is even if you brought the quench down even closer than what the OEM had them you couldn’t reduce your total timing. It may require a different curve but the total was the same.

The only time I worry about quench on a SBM is if I’m worried about dome height for compression. I don’t like building low compression engines. It’s a waste of power, economy and if done correctly, they are cleaner. If I can reduce the dome height by closing the quench gap and end up with the compression ratio I want then I do it. Otherwise I get it as close as I can and send it.

I know for a fact that guys who were big advocates of tight quench are coming off that stance. They are finding power by softening the chambers and in effect reducing quench. And that’s N/A. The power adder stuff has pretty much abandoned quench all together.

There is far more to making power and reducing detonation than quench. Especially with a SBM.