Perry Pump ?

[Chris ODonoghue]

Can someone please explain what a perry pump is, what it's used for etc and how it works ?

I've seen it mentioned in loads of different places, but still can't really understand it

[H2daB]

OK A perry pump is a device that is hooked up to the crankcase of your engine. The pressure changes inside the crankcase as the piston moves up and down. This varying pressure drives a diaphram inside the pump which in turn pumps fuel to the carburetor. The reason this is used is to insure a constant pressure fuel flow to the engine. Smaller engines generally don't require this as exaust pressure is enough to do this. In larger engines, however, it is not enough and so the engine leans as fuel is used. Therefore, the pump, or other means of pressure, is neccessary.

[Clintstone]

That kinda sums it up. I run the perry pumps and they work great for me. I noticed in Sulpher that Curtis was also running a C-Spec PS which as everyone knows it has a perry VP 30 in the back-plate. I recently found that a bi-pass tee works great but the check valve between the tee and the tank. This keeps the fuel pressure more constant to the carb.

[Chris ODonoghue]

thanks guys, just one thing though...

bigger engines

how big ?

[Clintstone]

Bigger engines usually refers to 91's as they pump more power for the stressfull moves and they also burn more fuel, more stress more fuel, HMMMMM , lets pump it or pressurize it in there. I have run the pressurized system on the 61's and I really like it but I have planned to try a 32 but never did it. I hope this helps. ;)

[Chris ODonoghue]

thanks for that :)

I don't need it yet then as I have a 30 and a 50