Transmission Grease Pump

Thanks Mike. Your information is well appreciated by me..

What should be kept in mind is SAE engine oil and 90W gear oil do not use the same viscosity scales. According to Lubriplate 90W gear oil is comparable in viscosity to 50W SAE engine oil. .
CORDiallyMike

Obviously my decimal point was in the wrong place, I stand corrected. It was just a test!!!!
CORDiallyMike

The tires on the front of the car were the special salt flat tires. They run Nitrogen and not air. I don't recall the pressure. They appeared to be about the same height of a passenger tire so around 30 inches tall. Tolling that at 435 mph gets the tire rotation in rpm. I'm not a math genius but I don't feel Al was teasing me. Al built this car over about 18 years of testing from a lakester with the wheels outside of the body to enclosing the wheels under the skin. He was the first to design the front end offset tires. They are not side by side but offset behind each other. This was done because of the narrow car design. He sold the car and now its located in a Nevada museum on display. Only the last year did he have a sponsor. That was Gale Banks who offered a telemetry computer. It showed the front wheels were off the salt at about 380 mph. He told me the return run was the only run where he was concerned about his safety.

Hi 1748 S
I figure the wheels on his salt flat car would have to be less than 2"
Was he pulling your leg?

The picture of the modified "grease pump" was taken in Henry Portz work shop when we visited in 2015. Henry increased the pump flow rate by fitting longer gears and a spacer between the pump body and cover plate. The radial clearance of the gears is minimal and this helps keep the pressure up when the oil heats up and thins down. Gary looking at the gears in your pump there appears to be at least 10 to 20 thou clearance between the gear teeth and the case.
Henry didn't mind me taking the picture he was a very kind person who would share information.

This pump is made to push heavy gear oil so.. It will have much looser tolerances than an engine oil pump that is made to handle a much lighter oil. Engine oil pumps are designed for pressure usually. Not volume unless your dealing with some diesel engines that have low pressure but very high volume oil flows. My work as a machinist in the power generating field has so many different types of "pumps" we dealt with all the time. I would like to examine what Henry has done only to see what its all about. These oil or as the book calls them... Grease pumps spin only when the tires are rolling. The pump is driven off the pinion gear shaft. So you have a rear ratio of say 4:10 this gear pump will turn 4.1 times per wheel rotation. Figuring that we have a very slow rotation of the wheels. Many years back I was talking with Al Teague, the worlds fastest man in a single engine Bonneville stream liner. I noticed some tire thread that was missing from the tires. He said that flys off at speed because it broke sometime. My question was what rpm are these tires spinning. Response was near 7600 rpm. Next question was how fast is the engine spinning...About 7400 rpm... Wow is all I could say. His top speed on the salt was 434 plus mph.... Our modest tires probably turn about 70 to 80 rpm at 65 mph...

Hello Mike,
I know the clearance needs to be kept to a minimum but I think you have the decimal point in the wrong place, 0.001"to 0.002" clearance is hard to achieve but 0.0001" to 0.0002 " clearance is very difficult to achieve if not impossible in the 1930"s. From my experience if you do the best yo can on the conventional machine tools 0.002" to 0.005" clearance is as good as you can get and most likely as good as production facilities in the 1930's.

Automotive oil pumps have a spec. of .0001 to .0002 between gears and housing, the same between gears and end cover, space between gear teeth, and drive shaft in housing bore. This can be attained by squaring up the gears, tightening up shaft to housing bore with new shaft, then hard chroming inside housing and grinding to fit the squared gears. This usually costs 4 to 5 hundred dollars in my experience.CORDiallyMike

Here are some finished machining pics. Nothing like what Henry was doing but it will work. The pump suction is always flooded with trans oil. I sure would like to see an oil pump rebuilt by Henry now. His picture is not clear in the detail as to how or what was done. I'm now thinking the body has at least 3 pieces under the cover.Maybe 2 but I'm not able to determine how the gear body bushings are installed or made. What Henry did looks very costly..

Thanks Terry. Henry did impressive machine work. I wish now I could have "shadowed" him on some of this work.Looking closely at this pump rebuild I see more of what he did. I see the "spacer" but further questions are what I would like to ask him. It appears Henry milled off the pump body where the flow channel and the gear bores were. Then a brass casting piece was installed. Then maybe a steel or cast iron housing around the brass piece was fitted. Nothing in the club booklet has any information on the axial clearance for the gears to the case they rotate in. It does mention we should have 2 to 3 thousands clearance between the gears and the cover. I like how Henry machined in the brass bushing in the cover. Doing that in my modest shop is very difficult but doable.. Lucky for me my cover is not worn out in this area. I wonder if Henry poured the cast brass piece under this steel piece too. Still very impressive work.

I am wondering about the radial clearance you will have on the gears as I feel this is critical to the pump working efficently.
Attached is a picture of a pump modified by Henry Portz although it has been extended with a spacer and longer gears the end view of the gears will be the same.

Bushing machined and fitted. Then the real job of finding the center of the driven gear stud and measure 1 inch plus 2 thousands per the trans shop repair booklet from the club. Sadly there is no mention of how to "find" the center of where the driven gear hole in the bushing is to be drilled to .500 plus 5 thousands clearance. No matter. I got the demention of the cavity the gear rests in. Divided by 1/2. Painted on some blue layout ink and used my vernier calipers to scribe lines to locate the exact center. Drilled pilot holes but had issues with chatter on my garden variety drill press. so now chucking the pump case up in the 10 inch 4 jaw chuck and indicating the center before I continue drilling to .505... Pictures later...

Today I had a chance to pick up my bushing material from McMaster Carr. I purchased 3 inches of 1 1/4 inch soild bar stock 932 bronze material. Chucked it up in lathe and trued it up. Maybe tomorrow I can make enough time to finish it and install it in the pump body.I'm finally getting some much needed spare time. My wife is improving quickly from knee replacement and my help is not so much required every minute of every day. We are both hoping to be able to attend the West Coast Meet in June.We will see later.

This is what I have accomplished so far. Made gears today. The last pic shows how I found my pump. No bushing to hold the drive gear and these were the gears in and out of it. the horribly worn gears were in a coffee can of spare parts.

Today O continued the restoration on my trans "grease" oil pump... I had the usual deep cuts from trash being ground into the body by the gears. Someone before me has opened up the buching area where the drive gear shaft fits thru the body. I used my drill press and a special set of round cylinder grinding stones to clean up the wear in the driven and drive gear bores. Both the body and the cover were lapped flat last year. Now to start cutting the gears on the lathe. If I mess this machining up new gears are easy to find. Pictures to come later...