Shoud I relieve my block

[Bored&Stroked]

Originally Posted by Ol' Ron

Well I guess I'm wrong. I'd like to see a flathead that makes one HP per cubic inch flathead on gas. I nolonger have the eqipment I used for my testing, so I can't comment on these reselts with any acury. I agree with the HD engine design as we looked at it back then. The Grancore heads were similar with a pop up piston. someone out there has them, Ford factory relieved blocks didn't last long and were designed to limit detention. I was told. But they never included it in the late engines or the 337. The French were just copying it.
Everybody has an excuse for their actions and beliefs , I stand corrected.
Gramps

Actually, you were not wrong - it is all about the application and usage of the engine. Relieving a Ford Flathead does nothing of value before about 4000 - 4500 RPM . . . actually it hurts low end power as it reduced compression (with everything else the same). Also, relieving is just one small piece of the overall puzzle - you have the ports to worry about (they take serious amounts of work), you have the cam to worry about, you have the valves, the chambers in the heads, etc.. As Pete noted - when all the things are specifically designed to work together (for racing) - then relieving is part of the "combo" that was typically used.

Also, typically these naturally aspirated engines were fuel injected - which surely adds horsepower over the typical Stromberg setup. And truth be told, the classical Hilborn flathead injector is too small for max HP. Guys like Don Ferguson Sr. cast their own injectors way back in the 80's - with big port/butterfly sizes more like a SBC injector (to get the flow they needed).

Then, one can start talking about oil-control, dry-sumps, crank scrapers, vacuum pumps, low-tension rings, straight-cut cam gears, etc.. A lot can go into one of these engines - and it is not for those "on the cheap".