GERRY - My knee had a run-in with a 7" x 1/4" grinding disc in my BIG Black & Decker 7"/9" angle grinder, it was spinning down to a stop and I rested it on my knee to turn the piece of steel I was grinding, the grinder shifted and bit a nice chunk of meat out of my left knee about 1/4" wide by an inch or two long.
I think what MATT is warning us about is the fact that aluminum alloys tend to build up on the aluminum oxide grinding wheels and stress them more because they don't "CUT" anymore, they wipe the built-up metal across the piece being ground and build up a L-O-T of heat. I think it's silicon oxide wheels you should use on aluminum. Or a carbide rotary burr.
Yep, once you pop the head off any flat-head engine, they all pretty much look the same, little differences in bore and valve sizes and relationships.
You look at today's engine designs, and they all tend to run individual runners to each cylinder. I always thought it was odd that IH had siamesed intake ports on their 4-cylinder engines, the 1-bbl side-inlet updraft carb with the manifold splitting in two at right angles with a runner going to both inlet ports in the head then those ports splitting in two to go to each cylinder. Small block Chevy heads had an exhaust port, then a pair of intake ports, then a pair of exh. ports, another pair of intakes, then the last exh port, across each head, and they typically made about one HP per cubic inch and one pound/feet of torque per CID on the higher tuned versions, like the 4 bbl and MFI engines. With the siamesed ports and the low RPM that IH's 4-cylinder tractor engines ran, they couldn't make much HP, but they DID make TONS of torque, like 267 #/ft from 164 CID @ 1046 RPM, 1.628#/ft torque per CID, Test # 492, Super H, and 363#/ft from 264 CID @ 991 RPM, test # 475, Super M, Super W-6 did slightly better @ 370#/ft @ 997 RPM, same exact engine, 1.40#/ft torque/CID. Relatively small bore but long stroke, and really really long conn rods. And they did that with about 6:1 compression on gasoline just slightly better than 70 octane and both made close to 12 HP Hours per gallon of gasoline. By comparison, a K241 Kohler, @ 23.85 CID makes .42 HP/CID at over twice the IH's RPM, but only about 1 #/ft of torque per CID, and burns over twice the gas doing it. THAT'S how much better an OHV design engine is compared to the flathead design. The basic IH H/M engine design dates back into the 1920's, the K-series Kohler was around during WW-II, Dad remembers Kohler powered generators when he was in the Army.
For comparison, the non-turbo version of my commuter car's engine makes 168 HP from 153 CID but needs EFI, variable intake cam timing, at least two computers, and 5000 RPM & 91 octane gas to do it, and it makes about 150#/ft of torque at it's peak. Amazing what 60 years of technology can do ain't it?
