It might if you sprayed enough in, but LC would be better for soaking pistons. Search on MolaSoke. In my view, Power Foam is too thin for a piston soak.
Power Foam is used mainly for top engine cleaning of carbon and for cleaning exterior of engine.
My method is to run engine until hot, and slowly spray into engine (at idle), keeping spray rate to the point where engine does not stall or quit. Use about 1/8 can of foam for this part.
Rev engine until smooth and then turn engine off.
Quickly spray about 1/4 can into intake system (throttle body). Let sit overnight.
Replace flame arrester/air filter and then drive normally.
I do this twice a year when I replace air filter and I see noticeable improvement in performance and engine smoothness.
[ May 25, 2004, 04:24 PM: Message edited by: MolaKule ]