VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 '32 oil pump; vane or gear

My 194 is being reassembled after an expensive rebuild. The shop asked if I had confidence in my original vane type pump. It read 5 lbs at idle and approx 10-15 lbs at speed before the rebuild. Pretty normal.
I've read the vane type is perfectly fine for this low pressure distribution system but I worry about its remaining operational life.

Ques: Do these pumps slowly lose pressure over time or by sudden failure ? New geared ones are expensive and beyond my budget.

Would you guys simply use the original pump and just keep an eagle eye on the oil pressure gauge ? I do anyway. Thanks !!

You have an expensive rebuild and since the oil pump is the "heart" of the engine what should you do? Replace it! Can't see installing a used oil pump in an expensive, brand new engine. When I did my engine I installed a new old stock, second design, vane pump. For the 194 engine a new vane pump will work great and it will put out sufficient oil pressure.

In your 1932 engine pressure is only an indication that the oil pump is operating. Volume or flow rate is far more important than pressure. Vane pumps are designed to produce sufficient flow. As long as the valve train is being properly lubricated the pump is doing its job despite the reading on the pressure gauge. I have used both and NORS vane pumps on my rebuilt engines with total confidence as long as the volume is sufficient.

That being written pressure becomes much more important indicator with directly lubricated bearings. 1932 is a significant transition from reservoir to direct lubrication.

A new vane pump would be fine but they were discontinued over 75 years ago.
I would say either take a chance on the old one or install a new gear type.
They do come up on Ebay from time to time. The new pump will fit basically 1930-1932....

Okay. This could be great fun trying to find a NOS or NORS replacement. Any leads appreciated !!

I poked around on Ebay and found a couple of NOS pumps. One seller says its for 1936 GM, geared pump w/ tube and screen. Says Bulldog on box. p/n 839157

2nd ad says for 1938-9 Chevy, unknown if geared or vane. Both listed for under a $100, so far. Box says Genuine All Metal Products.

Unknown if they would fit on my engine.

I'll post in the Wanted section.

Looking at the picture of your pump, things look pretty good. The length of your vanes look good and the pump plate is not badly scored. You can use a depth mic to check the distance of the rotor to the top edge of the pump sides. You can lap the pump plate using a machined flat surface or a piece plate glass with some 320-600 wet sand paper and remove any of the score lines you might have. You might be able to find a new vane spring somewhere if yours feels weak at all. As Chipper said, the vane pump design produces more volume rather than pressure. I know my own motor running at the same pressures you stated pumps a lot of oil up to the valve train with a lot of flow. So I would assume that yours is too. Without the need to pressurize the majority of the bearings, (I think the center main gets direct flow, but I might be wrong)I personally would go with your pump after checking those few things I mentioned. I doubt you'll have the ability to find any NOS vane pumps these days but I'm sure there still might be some hiding somewhere. I've worked on other types of equipment with the same style vane pumps and basically done what I stated above and gone with the same pump that was in the equipment.

I am a little surprised that you are getting suggestions to install a used oil pump on a new expensive engine rebuild, especially since the oil pump is the heart of the engine. At any rate, a NORS second design vane oil pump is not that hard to find. I located one on eBay in less than one minute. The pump featured here is the exact same NORS vane pump that I installed in my engine when it was rebuilt and it is a great pump. I have also seen many of the NORS vane type oil pumps for sale in the G&D in the past.

Here is the item number for the eBay auction:

The auction is a "Buy It Now" so if you want a new pump you might want to grab it up before it is sold.

381829239795

I rebuilt my oil pump as Chistech suggested and it works fine. It idles with close to 10 psi and at road speed of 30MPH or more puts out 20-25 psi.

Thanks guys ! The pump on Ebay referenced by JYD has a different bottom. The screen can't be seen and bottom is different than mine.
Mine has the screen exposed on the bottom. Is this just a slight modification since it's a replacement and not OEM ?

I'm thinking it would be best to purchase it , install and test, while I check or rebuild mine and maybe keep as a back up. I do not want delay this project any longer. I got to keep the rebuilder busy before he disappears again, if you know what I mean.

As I mentioned above, the NORS oil pump that is on eBay is of the second design. It has the flat bottom with a shield around the screen. It is a better pump than the first design with the exposed screen that hangs on the bottom of the pump. The first design pump was installed in the vehicles at the factory.


"He who hesitates is lost". Yes, definitely jump on it if you want a new oil pump in your engine.

Good find JYD! I agree, if you can find a new vane pump, the price is right, and the motor is new, put it in. (*see my observation of "new" at the end! LOL) But I wouldn't go with a new gear pump over a completely serviceable vane pump. Here is my reasoning to keep the original oil pump if the condition is good. The design of a vane pump (I'm basing this off of other industrial vane pumps and other engine oil pumps I've worked with and repaired through the years) is to have the vanes be sacrificial over the rest of the pump. The vanes are softer than the surface they ride on, are self adjusting, and that is the design. A vane pump is more of a "slinger" than a pressure maker, moving a lot of volume through the pump easily as there is little back pressure (as the oil trough design works). Even if the pump wall wears minutely, the vane, with the aid of the spring, contacts the wall correctly and still pumps the way it's intended. The wear points of concern are more the bottom of the rotor, the bottom plate, and the pump shaft/bushing/bearing. This wear is caused by friction of dirt in what ever the pump is pumping more often than anything else. If the shaft and bushing are good, the rotor's distance from the cover or pump body is the main reason for loss of volume if the vanes are good. This is why I suggested lapping the pumps plate. The whole pump body (edges) can even be lapped if necessary to decrease the distance. I worked with a lot of vane vacuum pumps that run at very high rpm and required close tolerances. We serviced those pumps just as I described and were able to keep pumps maintaining the required inches of vacuum for many years running 3 shifts per day, about 20hrs.
Gear pumps on the other hand are MORE likely to wear critical, non sacrificial and non-adjusting components. As a gear pump wears, the distance between the gears increases, dropping the pressure the pump can create. The reason for this is the higher pressure created, both by the actual compression of the oil between the gear teeth and the back pressure of the bearings/lubrication system. More often than not the gear shafts will wear allowing the gears to separate lowering pressure. Again, the pump body, gear sides, and bottom plate distances also come into play. In my work, I've always found gear pumps to wear more and need more replacement than vane pumps that can be more often, just serviced. *Another reason to stay with the original pump is the pump has been in the motor "X" number of years working correctly, it's proven and tested. We all have seen brand new components fail immediately or shortly after installation. I know my brother personally had at least two new high volume gear pumps fail in his drag racing motors. Those pumps were the best available on the market. Things just happen. I know many understand this, I just thought I'd post for those who might not understand the designs.

Whew ! How many cups of coffee behind that post ?

The Ebay vane pump is on it's way to me. Thanks again !

There's a chance now I'll get my engine back before I go into assisted living.

Just one good size one. You should see me on a pot! Do that before going out to the garage!

Great! You did the right thing. As you have learned, those early six cylinder oil pumps are not that hard to locate after all.

Good luck with your project!

If for some reason it does not work out I have quite a few nors oil pumps. The ones still in boxes are Wohlert brand. On the boxes it shows they replace part number 473730, some 604597. Both show fitting 29-32 and 33,34 Standard. Looks like some are gear and some are vane. The unboxed pumps have a casting number of ?W-837754. They have the round oil pick up screen. Let me know.

Dave

The Wohlert NORS vane pumps that you have are excellent and that is exactly what I have in my car.

I had a GM replacement gear pump in my "34 and would never had trusted the vane pump because I drove it at high speeds for long distances.
Chevrolet changed to the gear pump for good reasons in 1937 and the replacement pump they sold for previous vane pump models is a 1937-1939 design pump with all the hardware to install it.
For the 1929-1931 models that lacked full presure to all the main bearings the vane pump was fine. NOt the pressue means every thing but my '34 ran at 17 pounds hot at 50 MPH and 7 pounds at idle. The ger pump makes for a more steady flow of oil .

One question on the Wohlert box it lists 29-32 all and 33-34 Standard. The BP and FS catalogs have 29 separate. Any ideas on why the difference and if the Wohlert would work on a 29?

A side note, Wohlert is still in business and a supplier to many auto companies. They seem to specialize in ring gears now.

Dave

Like the application on the box states, the Wholert oil pump will work on a 1929.

The parts book from 1935 lists oil pump (vane type) as fitting all 1929-1932 + 1933 and 1934 Standards. That is the improved pump with the round screen which comes with the pump and you will need....for $2.75.