Speedway Motors oil pump vs. stock Ford (Mercury) unit

[JWL]

And the alternative is the spring material strength begins to fade at hot temperatures.

[sidevalve8ba]

I've got several old pumps around the shop. What's a good source for new springs?

[cmbrucew]

All gear pumps the output is determined by the gear size in gpm. The pressure in the the system will be controlled by the relief spring pressure. for these applications cavitation should not be a factor. In an older engine worn cam shaft bushings are the first culprit to look for.
Stock applications do not require Hi flow or high pressure.
Bruce

[GB SISSON]

I thought I would post up a response on this excellent thread about the use of used oil Ford oil pumps. Sadly, in searching the topic, this thread with it's 'all-star' cast did not show up. I have made a very simple pump adapter and plan on testing 5 short body pumps this afternoon. I had thought I might make an apparatus to see how far each pump would lift a column of water up a vinyl tube, but now I see that just introducing an oil pressure gauge as a dead end and recording at what psi the relief valve opens should be less complicated. Yesterday my first pump shot a solid 3/8" diameter stream of hydraulic fluid 10' across my driveway. I figured I'd respond here so future 'barners searching the subject would find this test as opposed to wandering through a long and sometimes wandering engine build thread. Speaking of 'wandering'.....