1924 Master oil pump.

[1924 6-55 Sport Tourer]

Something that has been puzzling me that i'm sure someone here can answer for me.

 

I have just picked up my oil pump after having new fears made (2 × pump and camsgaft drive gear).

 

My question is, why is the "driven" pump gear secured via a tapered "nut"?

Is it some sort of safety or pressure relief mechanism?

The bronze nut has a left hand thread.

I forgot to include in the photos the heavy compression spring  that is always ensuring a firm fit/engagement of the nut within the gear. (Does that make sense?)

 

If more photis are required i can provide.

 

Thanks in advavce.

 

David.

 

[Leif Holmberg]

That looks a little bit strange to me.Here are pictures from 1923-1924-1925 "Master" parts book.It looks like you should have asked this question before made the new ones!

Leif in Sweden

[1924 6-55 Sport Tourer]

Thanks for your quick reply Leif.

 

All i did was replicate the parts that i removed from the engine, and therefore renew the gears due to excessive wear. The parts are no doubt (to me) genuine Buick components.

I don't have a parts manual, but part 173334 looks exactly like my "driven" gear.

The spring pushes up onto the collar and "lifts" the shaft up into the pump gear, thus engaging the bronze nut further into the taper inside the gear. This gear and shaft assemble inside part 165487.

So, the questions remain. Why the taper and secondly what purpose does it serve? 

 

David

[1924 6-55 Sport Tourer]

Just re reading my original post.

 

I dont think i was very clear in my initial description.

All that was re manufactured were the three gears. The shaft, tapered nut c/w left hand thread is as found/original to the car.

 

David

 

[Brian_Heil]

The drive gear on a Buick oil pump has the spring loaded sort of clutch feature you mention. Should the pump freeze up in cold weather due to heavier than oil water freezing in the pump, the spring loaded drive feature will slip and not break the pump or drive or drive gears at the cam.  This slip feature also created heat from the friction and quickly unfroze the ice in the pump.  Pretty smart chaps those Buick Engineers. 

Edited September 23, 2018 by Brian_Heil (see edit history)

[dibarlaw]

I had checked the oil pump on my 1925 Master. I lapped the bottom plate. There was .020 side play on the shaft. It was not so much the gears and shaft that were worn but the housing. I also pulled the pump from my spare 1924 engine as the gears and pump body are the same. Unfortunately they were worn exactly the same amount. The driven gear shaft had worn an elliptical on one side of the bore. The idler gear was ok. I had the shop make a new bushing and things are now in alignment and within spec. I still have to install.

[1924 6-55 Sport Tourer]

Thanks Brian,

I knew someone would have an answer for me. When you think about it, it is quiet a logical design.

Onwards and upwwards. Now i start to assemble the engine.

More photos to folow.

David.

[rodneybeauchamp]

13 hours ago, 1924 6-55 Sport Tourer said:

Thanks Brian,

I knew someone would have an answer for me. When you think about it, it is quiet a logical design.

Onwards and upwwards. Now i start to assemble the engine.

More photos to folow.

David.

 

Hi David,

just noticed your “down under” address. We both love the “apple isle” and have visited three times already.

Good luck with your project.

Rodney ?????

 

[1924 6-55 Sport Tourer]

Good morning Rodney,

 

Thanks for those kind words. When you're next visting this "island state" please be sure to look me up.

 

David