OK, let me preface this with I'm building a speedster with the intention of having as many accessories that were available for the "T" added in the build, that includes the dreaded water pump. Total engine rebuild, new radiator etc. Do I need a water pump? No. Was a water pump a well known accessory? Yes. With that said, I'm rebuilding a "Buckeye" pump and thought I'd replace the shaft with stainless. In the back of my mind I remember reading brass bearings don't like contact with stainless steel. Any input?
I remember reading brass bearings don't like contact with stainless steel. "END QUOTE"
I think you'd be o.k. with bronze bearings and a well polished shaft. And, grease of course, but you knew that.
We use stainless in bronze pump bushings all the time. No problem.
Not all stainless is equal. When they started making "leakless" Model A water pumps with a modern seal, I had one of the first ones. Within several hundred miles the neoprene seal had worn a groove in the stainless shaft. They sent me a replacement shaft and it did to too, but took a bit longer. Just for giggles I TIG'ed up the groove with H-13 rod, reground it, and got quite a bit longer life out of it than the original or replacement shaft, though it also eventually wore a groove, too. That's not so much a problem today, so they must have changed the series stainless they are using. I just mention that to illustrate the point that materials compatibility is a complicated subject.
(Message edited by Wmh on September 14, 2017)
Nice thing is this type will use packing not a lipped seal. I have been using SS shafts on any water pump I rebuild A or T types, no issues I am aware of in regards to being in contact with brass bushings.
Never had a problem with stainless/brass galling. But I have encountered severe shaft wear when using lip seals on unknown alloy stainless steel shafts before.
I prefer to use prehardened 17-4 PH S/S for such an application. In H900 condition 17-4 PH is about 44 hrc. It is usually available in centerless ground round bar with a +-.001 diameteral tolerance. Even in hardened condition, it still machines fairly well with conventional tooling... Especially lathe tooling. Very resistant to corrosion too!
Of course one could go with many different series of S/S, but if you consider the complications of heat treatment, availability, and surface condition... My recommendation, as stated above, is 17-4 PH S/S H900 condition.