stakeside

Kingston Vacuum Amplifier

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Found this vacuum amplifier in my “bone pile” and may use on my Steward tank. This the pot metal version with the brass insert. 

 

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The brass insert with the orfice came out and there is a small brass ball inside of the camber. What is the purpose of the ball?

The orfice has been enlarged and should be #51 drill size.

Can I silver solder the hole shut and redrill with a #51 drill?  The orfice in the pot metal portion is also enlarged. Will this have to be a #51 orfice also?

I attached a portion on the “DB Club Article” for reference.

 

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Edited by stakeside
E (see edit history)

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Nice piece of history,  but I think they are  rare for a reason. I question if it's needed for anything more than using vacuum wipes with a wiper motor that needs some TLC. A good sized vac wiper motor, in good condition, usually just slows a bit but shouldn't quit on a long hill.

 

As for the engine running out of fuel on a long hill, I'd look for causes instead of treating a symptom.

 

With a properly functioning vacuum tank,.....

and with a good running motor,...

and not lugging the motor up a hill in too-high a gear that requires the gas pedal to be pushed to the floor.....

at 4 in/hg on a vacuum gauge, which is below the point where many carb's open their power enrichment circuit for hill climbing,...

the vac tank is still producing 2 PSI pressure in the fuel line to the vac tank,...

which is what many late 1920s and early 1930s mechanical fuel pumps produced as the low end of acceptable fuel pressure range.

 

Paul    

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Whilst I wouldnt question your reasoning on the necessity of a vac amplifier, in the real world a long hill or even a strong headwind at large throttle openings, is a not uncommon reason for a vac tank not being able to keep up with engine demands. Most of us would probably never encounter this problem as the majority of our motoring is at city speeds on the straight and level; commercial vehicles were a different matter with loads and distances significantly greater often requiring the fitment of a booster.

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Still need any ideas on rebuilding my booster valve.

The orfice has been enlarged in the brass insert and should be #51 drill size.

Can I silver solder the hole shut and redrill with a #51 drill?  The orfice in the pot metal portion is also enlarged. Will this have to be a #51 orfice also?

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You can solder and redrill the stamped plug, as long as  you don't get the solder too thick. It's not just the diameter of the finished hole that affects air flow, it's the length of the hole, too.

 

As for the Venturi, the size and location of the narrowest point in relation to the opening that you want to boost the vacuum  (pressure drop) from is very rather critical. Without the original drawings you might get the narrowest part the wrong diameter, and/or, in the wrong place.

 

Paul

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Paul thanks for comments. Is the Venturi in the main body a #51 hole also? I am concerned more of the correct location and lenght of the hole in the main body. 

As it sets right now the booster is not useable since the hole has been overdrilled.

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Looking at the location of the stamped plug (I think that is where it is, where the diagram label #51 hole is pointing) it is immediately above an inlet. 

 

Bernoulli's Equation says the static head plus the velocity head (v2/2g) plus the pressure head are a constant. Static head is constant here. Thus by increasing the velocity in the pipe, the pressure of the fluid in the pipe is reduced. If there is an inlet at that point and the lowered pressure is below the ambient pressure in the inlet, fluid will be "sucked" in. The pressure in the inlet can be decreased.

 

So your #51 hole should be short as said and immediately above an inlet, so maximum velocity is at the inlet.

 

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9 hours ago, stakeside said:

Paul thanks for comments. Is the Venturi in the main body a #51 hole also? I am concerned more of the correct location and lenght of the hole in the main body. 

As it sets right now the booster is not useable since the hole has been overdrilled.

Sorry, I'm not familiar with what the inner dimensions of the Kingston should be. I've only seen and have measurements of the Stewart Warner booster, which is a very different shape than that Kingston. 

 

Paul

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Thanks for consideration. If still for sale send me a private message.

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Hello!
I need exactly the same fitting for this kingston vacuum pump! I have a 1929 chrysler series 65 business coupe. preferably several pieces, or even the entire tank!
I am from Austria, Europe. Please help! Thank you!

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The size of the orifice is calibrated and very critical. The one I have has been drilled out for some reason.

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