Post by finiteparts on Jan 17, 2015 18:08:20 GMT -5
Mitch,
I have an Acura steering pump that worked like a champ...once we ditched the Shurflo pump that had the failed diaphragm, we scrounged around and found this steering pump. It worked well enough back then, but I have to admit that we didn't check the flow rate.
The only real disadvantage is that the internal pressure bypass valve doesn't crack open till you get to very high hydraulic pressures (like 1200 psi or so)...so if you want to limit the peak pressure, you have to either have a way to control the speed, have an external bypass or modify the spring for the internal bypass. But if you didn't care how high the pump pressure goes, then this isn't an issue. The beauty of using a power steering pump, is the pulley is already on it and the pump is fully sealed. We snagged an alternator pulley also and fit it on a 1/2 hp a/c motor. We "controlled" the motor speed and thus the pump pressure, with a variable a/c transformer (Variac) so we were not limited to the set speed of the motor...but thinking back on this, we should have checked the flow rate, not just the supply pressure at the turbo inlet. We didn't change anything internal...
John, is that what you were referring to about internal changes, the pressure relief cracking pressure?
Since any constant volume pump (gear, gerotor or vane) will generate the pump pressure based on the flow restriction and the amount of mass that we are trying to push through it, which for us, the restriction is set by the bearing housing of the turbo and essentially is a constant, we were basically just changing the volumetric flow rate and may have had the oil flow rate too low. I may have to dig that think out of the garage and check it when it gets warmer outside.
But, if you are wanting to use a 12 VDC source, it may be more of an issue to use a PS pump. Also, the fittings on ours were special, so we had to get the high pressure line (we left it on the pump when we pulled it off the car and the junkyard didn't charge us a dime for it!), cut it and splice in with a Swagelok compression union to get our tubing to fit up.
The only concern with the pump that Mark suggested is that it is designed to be inside the engine, in the oil pan. There are no seals on the shaft and the pressure relief just squirts directly out of the pump, right back into the pan...so using it outside of the oil tank is probably not going to work. But, if you mounted your pump down in the oil tank, then this wouldn't be an issue...the drive motor would have to be protected somehow, maybe behind a shaft seal. But, chain drive is cheap and it might be a good option. I bet you could tap those housings for NPT fittings...but I would have to check one out to say for sure, since we can't see how deep the housing is at the larger inlet section.
Good luck!
Chris
I have an Acura steering pump that worked like a champ...once we ditched the Shurflo pump that had the failed diaphragm, we scrounged around and found this steering pump. It worked well enough back then, but I have to admit that we didn't check the flow rate.
The only real disadvantage is that the internal pressure bypass valve doesn't crack open till you get to very high hydraulic pressures (like 1200 psi or so)...so if you want to limit the peak pressure, you have to either have a way to control the speed, have an external bypass or modify the spring for the internal bypass. But if you didn't care how high the pump pressure goes, then this isn't an issue. The beauty of using a power steering pump, is the pulley is already on it and the pump is fully sealed. We snagged an alternator pulley also and fit it on a 1/2 hp a/c motor. We "controlled" the motor speed and thus the pump pressure, with a variable a/c transformer (Variac) so we were not limited to the set speed of the motor...but thinking back on this, we should have checked the flow rate, not just the supply pressure at the turbo inlet. We didn't change anything internal...
John, is that what you were referring to about internal changes, the pressure relief cracking pressure?
Since any constant volume pump (gear, gerotor or vane) will generate the pump pressure based on the flow restriction and the amount of mass that we are trying to push through it, which for us, the restriction is set by the bearing housing of the turbo and essentially is a constant, we were basically just changing the volumetric flow rate and may have had the oil flow rate too low. I may have to dig that think out of the garage and check it when it gets warmer outside.
But, if you are wanting to use a 12 VDC source, it may be more of an issue to use a PS pump. Also, the fittings on ours were special, so we had to get the high pressure line (we left it on the pump when we pulled it off the car and the junkyard didn't charge us a dime for it!), cut it and splice in with a Swagelok compression union to get our tubing to fit up.
The only concern with the pump that Mark suggested is that it is designed to be inside the engine, in the oil pan. There are no seals on the shaft and the pressure relief just squirts directly out of the pump, right back into the pan...so using it outside of the oil tank is probably not going to work. But, if you mounted your pump down in the oil tank, then this wouldn't be an issue...the drive motor would have to be protected somehow, maybe behind a shaft seal. But, chain drive is cheap and it might be a good option. I bet you could tap those housings for NPT fittings...but I would have to check one out to say for sure, since we can't see how deep the housing is at the larger inlet section.
Good luck!
Chris