Thread: Domed pistons and quench?

Tweet

Going back to domed pistons for a moment.....

I remember experiments conducted by Ak Miller on the Ford 2.0 and 2.3 motors. He made more horsepower with a flat-top piston over a domed piston although the scr was higher with the domed piston. It was a matter of the dome getting in the way of the flame kernel as it travelled across the chamber and effectively "putting out the fire". Same thing with the Chevy Vortec head #12558060 L31. Chevy recommends a flat-top piston with that chamber for the same reason. Domed pistons show less horsepower.

The answer for a naturally-aspirated high scr motor is a flat-top with small chambers. Include a tight quench if you plan to run pump gas and keep the scr at 11.0:1 or less. Proper matching of the intake closing point on the cam is mandatory.