supercharging · FF-0414

What is the difference between a 174 and a 177 supercharger, and how is the 177 adapted?

The numbers are displacement: 174 and 177 cubic inches per revolution, which Steve calls really no difference. He first had the H&H blower intake machined for a 174, the blower used on the engine tested earlier, whose hold-down bolts run through its front and rear bearing plates. The 177 has a wider bolt pattern than the manifold, so his adapter plate bolts to the manifold through the four 174 holes, and the 177 mounts on top of the plate, in front of those bolts, so they are outside its sealing surface.

Expert

Steve Coppock

Evidence

expert attributed

Component

174 and 177 superchargers

Applicable scope

Steve Coppock's supercharged ARDUN overhead valve Flathead, mocked up before its dyno test