250 bore
- Thread starter kat4568
- Start date
NO, safe would be 3.72, and even that might be a bt "iffy" in an older black with corrosion problems. 3.80 would run out of block!
The reason I'm asking about the cylinder bore diameter is, I found a set of pistons that will work with my build that are 3.80 dia. aussi7mains helped me eliminate those pistons. I also found another set that are 3.691 dia that will fit the build.
My build will be those pistons, 300 rods, 3.91 stroke. The head is an E0 head with 3 740 webers. The cam will be a .515 lift 280 duration 110 LSA. I am getting ready to retire and am going to build this engine. I have 4 more heads and plan to build a 2 carburetor head, and independent runner intake for these 3 carburetors. My goal is 250 to 300 horsepower.....
My build will be those pistons, 300 rods, 3.91 stroke. The head is an E0 head with 3 740 webers. The cam will be a .515 lift 280 duration 110 LSA. I am getting ready to retire and am going to build this engine. I have 4 more heads and plan to build a 2 carburetor head, and independent runner intake for these 3 carburetors. My goal is 250 to 300 horsepower.....
an alternate 250 Piston in my '61 is AMC/IHC 4.2/258 (TRW/SealedPower # 470NP std) Pistons require an .070 over bore to 3.75" .
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The trick pony' of these pistons is the CH raises piston height .133 about where stock pistons are down from deck similar amount -
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AND specs list the pin diameter of the ford at .9122 and the AMC's at .9310 which can easily be accommodated.
from the wayback machine:
"The AMC Pistons depression is much bigger than a 200/250 piston , 2 to 3 times the volume. CR lessened significantly and still maintain zero or negative deck height with the .133 additional compression distance"
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hav e fun
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250/258 will launch at 5500 and still has drivable low RPM grunt ...
.
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The trick pony' of these pistons is the CH raises piston height .133 about where stock pistons are down from deck similar amount -
.
AND specs list the pin diameter of the ford at .9122 and the AMC's at .9310 which can easily be accommodated.
from the wayback machine:
"The AMC Pistons depression is much bigger than a 200/250 piston , 2 to 3 times the volume. CR lessened significantly and still maintain zero or negative deck height with the .133 additional compression distance"
.
hav e fun
.
250/258 will launch at 5500 and still has drivable low RPM grunt ...
.
That piston is only .011'' larger than stock, I do not see it cleaning up with so little to work with. I had a very hard time finding one that would clean up at .020'' and that block had air bubbles in the bore casting. Keep in mine that #1 bore wears more than the rest.
