1927 Vacuum System Question

[Guest M R Simpers]

I have rebuilt the Stewart Vacuum tank for my 1927 Dodge Brothers, because I wanted to remove the incorrect electric fuel pump.

This car has a vacuum windshield wiper, and I need to tap into the vacuum line that runs from the manifold to the vacuum tank.

Any idea how this wiper will impact the operation of the vacuum fuel system; which is to say, how much vacuum demand is drawn by this wiper to the detriment of the fuel system?

Would it be prudent to put a small restrictor in the wiper suction line?

What say?

M.R.

[W_Higgins]

It shouldn't hurt a thing. Your car was designed for both and there are examples of other cars that produce way more vacuum demand than what you have there.

[HarryJ]

A normal engine will pull 16 to 18 inches of vacuum, the vacuum tank only requires 2.5 inches to work. I should work just fine.

[Guest M R Simpers]

Walter and Harry,

Thanks for your comments.

I am going to continue with my vacumm line assembly efforts. I bought this car in Jan. 1975 and haven't started her in 15 years. I'm cleaning, painting, rebuilding, sprucing up, etc. Just hope she will start.

Thanks again....

M.R.

1927 Dodge Brothers, Series 124, Cantrell woodie Suburban

[stev1955]

Where did you find information on how to rebuild your vacumn tank? I need to do it on my 30 essex this spring/summer. Thanks.

[Larry Schramm]

Here is a good link on the Stewart Vacuum tank

http://hudsonterraplane.com/tech/1927/StewartWarnerVacuumTank2-11-27.pdf

[hchris]

Just a word of caution where vacuum wipers and fuel systems are concerned. As vacuum is dependent on the throttle position, it stands to reason that vacuum will be at its highest when the throttle is closed, such as at idle, or when coasting with foot off the pedal. It will be at its weakest when you are pulling up hill or with the engine under load, say into a headwind.

If you strike a situation where both wipers and fuel are sucking hard and your engine is under load, say a long climb or stiff headwind you may well find that the wipers at best will be working very slowly and at worst the carb may run out of fuel, because their is not enough vacuum to lift sufficient fuel up out of the tank and keep a head of fuel in the vac tank.

It pays to be aware of this if you are on tour and mixing it out there with all of the other traffic.

[stev1955]

Here is a good link on the Stewart Vacuum tank

http://hudsonterraplane.com/tech/1927/StewartWarnerVacuumTank2-11-27.pdf

Thanks Larry.

[sambarn]

As far as tapping into the vacuum line goes, the wiper should feed from the top of the vacuum inlet from the manifold, usually a tee with male threads on the bottom to attach to the tank lid (be very careful these things break ALL the time) a female on top (usually much smaller) for the Wiper motor and a Tee off of the side usually designed for flare fittings. I just finished rebuilding three of these and while I'm no expert, I'd be glad to share my experiences with you. - Sam