Which Pistons for Pulling?

[Allis38WC]

Which would have more power in a Allis WC engine with a WD45 crank, flat top or cup pistons?

 

[jd plowboy]

i like flattops

 

[BushogPapa]

Flat-tops are going to REQUIRE High Octane Fuel..

You will too high a Compression for anything less, or Detonation will destroy the engine (Bearings, Rings and Pistons)..

Ron.

 

[cotncrzy]

Go with flat tops! You can get by running 100LL avgas. It wont run on 92 pump gas trust me.... The less octane you can run without detination the more HP you will make.
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[warwagon01]

4" bore i"m using d-17 pistons