carburetion · FF-0497

How can you tell if a carburetor is too small?

Measure the pressure at the base of the carburetor, where vacuum would be read on the dyno. At wide open throttle you want about one inch of mercury or less; more than that means the carburetor is the restriction. Steve says people are surprised how big a carburetor it takes; on paper a 750 is too much for the ARDUN, but on the dyno engines always want a bigger carburetor for power.

Expert

Steve Coppock

Evidence

expert attributed

Component

carburetor sizing

Applicable scope

General engine practice; not specific to the Flathead; discussed for the ARDUN Flathead