How many HP to spin an injection pump?

[addautomotive]

I want to do some experiments to see how long it takes to flush out veggie oil at idle, at load, etc etc. I'd monitor the amount of fuel being sent out the return, how much is going out the injectors, and how long it takes before straight diesel is sprayed out the injectors.

What I want to do is hook up an electric motor to spin a spare injection pump that I have.

Anyone have any idea how many HP it takes to spin one?

[QuickTD]

Depends a great deal on the speed and throttle position. Most test benches have at least 10hp on them, but they get used for much larger pumps. I find the 7hp lathe at my shop has no trouble spinning one with the injectors hooked up, but I have some trouble holding on to it... I would think that for your purposes 2-3hp would be in the ballpark. You'll need to reduce the motor speed (normal motors are ~1750rpm) with a belt reduction of about 1.5:1 to correspond to 2000 crank rpm. Lots of flywheel on your drive mechanism helps dampen the torque pulses and make sure to find a way to securely fasten the pump, don't say I didn't warn you...

[Mark(The Miser)UK]

Just do 2 quick experiments on your car:

1) put half pint of diesel in a jam/-butter jar. Drop supply and return pipes into it. Run engine on idle for 2 minutes. Stop engine. Allow diesel to cool. Measure usage divide by time rpm and 4 to get individual injector use.

2) reconnect supply diesel from tank. Empty jar and replace under return line . Run engine for 2 minutes stop and measure. This gives you flushing flow rate.

Volume from injector's return is miniscule. Leaks on those return pipes are actually from the pump return reverse flowing up the pipes. This shows you just how 'massive' the returning unused diesel is.

Another method is to sniff the exhaust until the veggy smell changes.