Jackpiner piston skirt

[Doug Knight]

I am in the final stage of an overhaul and the early manual calls for trimming the intake piston skirt to a line of opening at btc/atc of 80 degrees. Do I need to do this? The engine in question is a 4-52xxx. I also pulled down a 2-52xxx, neither engine had the intake skirt trimmed.

Is there any benefit or not for doing this procedure?

Doug in Martinez

[Kip Kern]

Built a ton of them and never did it. Merry Christmas!

[joe novak]

Would trimming the intake skirt affect the flow into the crankcase?   On race engines, I always trim the skirt to be sure the skirt does not obstruct flow into the intake port.   joe