Kvach; Flathead Fords were 221 and 239 cubic inches. Mercs after 49 were 253
I think. Gmc engines from the late 30s were 270 easily bored to 292 cubic
inches and after 51,302 cubic inches stock. You had to stress a flathead a
lot to get where a jimmy started. If you increase CR in a flatmotor you close
off the transfer area between the valves and cylinder. So you must choose
which you want most. Overhead valve motors do not have this problem. Jimmies
have 4 mains Fords 3. Fords have impossible exhaust ports GMC could be better
but they are OK and they don't hold heat in like a flathead. The speeds that
were achieved with flathead Fords in the early days is phonemail to me. Just
proves that hard work and ignorance will beat book learning anyday. Rich
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