#Squish head how to

Swirl is happening from the center of the piston outward, injection plumes are deflected and contained within the bowl.Īs the piston reaches top dead center we get squish. Injection starts with added high RPM swirl causing a better air/fuel ratio. The swirl rotation is clockwise in a Duramax.”

#Squish head how to

“Now let me show you how to do it correctly. This is a view of a piston prior to top dead center with proper swirl. “The piston will get to a position that the spray angel starts breaking out of the combustion chamber.” The result is excessive EGT, piston damage and fuel that sprays the cylinder wall along with continued soot formation. Shot of top dead center still spraying fuel and creating excessive soot.Įxtended injections shown. “In this shot the piston has risen up the bore to the point on injection.” With no swirl there is nothing to help blend the fuel with the air, producing soot and high temperatures. There will be no valve reliefs on the top of the piston.” “This slick-top piston is what you’ll see in virtually every production diesel engine. View of a standard piston with cross section. This is definitively the best information you’ll ever get about diesel combustion outside of engineering school!īelow, you’ll find the squish and swirl diagrams used in the episode. Gale reveals why “squish” and “swirl” are so important to the proper diesel combustion as well as other important factors like valve timing, duration, overlap, and even goes over the details on why he prefers a stock piston versus one with valve reliefs. Gale collaborated with Comp Cams in the development of this new high-performance Banks-spec camshaft and explains how he analyzes each step in the 4-stroke process of a diesel. The “Killing a Duramax” series makes its triumphant return with part 14! Gale’s been busy with the design of the new L5P cam as he tries the get the most horsepower while cranking out new ideas.