Topica Loopframe_Guzzi Archive


Subject: Re: To crossover or not to crossover???

Author: GuyW

Date: Mar 31, 2005, 5:32 PM

Post ID: 1718630019



"The function of the crossover is to allow the exhaust pulse to be shared by
both pipes - thus reducing the overall pressure drop of the system. In
addition, the crossover (often called an H-pipe) allows the exhaust pulse
from one cylinder to pull, or scavenge, the spent gases from the other
cylinder - improving volumetric efficiency and HP output."

"Crossovers are good for a 5% improvement in HP on the average and have a
significant effect on the area under the HP curve - especially in the
midrange."

Maybe - but Dave Schnieder of Schnieder Racing Cams here in Sandy Eggo (an
ME and experienced racer) told me that H-pipes on American V8s did nothing
but 'mellow' the exhaust tone (he preferred the 'raspier' tone from separate
cyl banks).

Ran my '70 Ambo without the H-pipe (part of the stock mufflers) and
aftermarket muffs for years - bike ran quicker and better (was my
perception).

-Guy-

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