How much power does it take to run a Convert fluid pump?

[Antietam Classic Cycle]

I have a theory that the atf pump does 2 things. One is it circulates the atf to run it thru the cooler. The second is, it forces the atf into the torque converter where the spinning of the TC wants to force atf out. In this way, it has to have more pressure forcing in than the TC has a tendency to expel. I'd bet that the higher the RPM the more the TC wants to eject oil, so the atf pump needs to have a higher pressure at high rpm. Luckily it is cam rpm driven, and so should up to a point produce more pressure at higher rpm. by going with a constant pressure pump, you have to scale it for the worst case, and at low rpm might be forcing too much pressure into the TC. Source of leaks? who knows... I hope not. Maybe that is what the 2ndary return to the atf tank is for.

The bypass pressure relief valve of the original pump is set ~ 28-30 psi, so pressure can't go any higher no matter what the engine speed. As for too much at low speeds? Guess we'll find out. But, Dale Peterson ran an electric pump with external regulator set at a constant pressure (30 psi) and had no issues that I'm aware of.

[Muzz]

The pump is a trocoid type.

As far as I know, it will be pumping something like 2-3 gallons per minute maximum at 30 psi.

All the talk of the various types of pumps is outside my knowledge zone. However, one thing I do know is that a trochoid pump will continue to pump at full volume at high speeds, as the fluid is effectively trapped in the cavity and has to go out the prescribed exit. They do not suffer from the effects of fluid shear which can happen in a gear type pump at high speeds.

At the end of the day, it probably does not matter too much for the use that you are putting it to.

[Groover]

^ Thanks for posting that pump photo Rodekyll. Clarifies things in my mind. What do you use to measure the flow?

[Zoom Zoom]

The bypass pressure relief valve of the original pump is set ~ 28-30 psi, so pressure can't go any higher no matter what the engine speed. As for too much at low speeds? Guess we'll find out. But, Dale Peterson ran an electric pump with external regulator set at a constant pressure (30 psi) and had no issues that I'm aware of.

And as far as I know, Dales bike is still running well and lives in Florida. (I think Tim Hewett's (sp) wife IIRC.)

John Henry

[wymple]

I really don't see the need to vary the pump speed since I can just set the desired pressure and run the motor/pump at a constant speed.

This

[chuck peterson]

Lol....I have an answer the op's question...it takes an entire convert motor to run a convert fluid pump...not much left for the rear wheel, really...

[Antietam Classic Cycle]

Lol....I have an answer the op's question...it takes an entire convert motor to run a convert fluid pump...not much left for the rear wheel, really...

  Kind of like hydrostatic riding mowers? Use 1/3rd of the horsepower to make the thing move. That's why I have an "old" '84 Gravely - all gear drive, 8 spds forward and reverse.

[jrt]

Charlie, I was hoping you would put a line shaft in the tunnel and run a pump and an alternator off that.

OK, I'll lurk again.  I am enjoying your work!  Very creative stuff!