Where to harness the power of vacuum?

[WillyR]

Where would be the best place to access engine vacuum?

I have a spare intake heat exchanger and was wondering if I could harness enough vacuum just ahead of the carburetor.

The only other place I can think of is on the intake manifold, but that would be post carb and would possibly interfere with combustion/fuel/air mixture etc…


I actually stole this picture from this site, I would put the line as close to the carburetor as I could.

[Allan]

Post carburettor is the way it is done on my 1924 Tarrant Special tourer which has the fuel tank under the spare tyre carrier at the rear of the car. This is needed for a Stewart vacuum tank for fuel delivery. The same applies to another car modified by Duncan and Fraser to accommodate a dropped fuel tank under the front seat.
You will not get much vacuum from an ill fitting heat shield on a T carburettor.

Allan from do.wn under.

[A Whiteman]

I have vacuum taken off the inlet manifold after the carburetor. This is used to power my Trico vacuum windscreen wiper. It is by way of a brass tube fitted into a hole drilled in the inlet. This is the usual location used locally and gives no impact on combustion as it does not alter the mixture as such and barely affects the volume of flow into the engine.

[WillyR]

I have vacuum taken off the inlet manifold after the carburetor. This is used to power my Trico vacuum windscreen wiper. It is by way of a brass tube fitted into a hole drilled in the inlet. This is the usual location used locally and gives no impact on combustion as it does not alter the mixture as such and barely affects the volume of flow into the engine.

29 Feb 08 (12) (Large).JPG

Dec 28a (Large).JPG

Post carburettor is the way it is done on my 1924 Tarrant Special tourer which has the fuel tank under the spare tyre carrier at the rear of the car. This is needed for a Stewart vacuum tank for fuel delivery. The same applies to another car modified by Duncan and Fraser to accommodate a dropped fuel tank under the front seat.
You will not get much vacuum from an ill fitting heat shield on a T carburettor.

Allan from do.wn under.

Thanks,

I do believe I'll scavenge it with a 90* off the backside of the intake manifold.

[browning]

For one of my oil pump assemblies I fabricated a plate the size and shape of the carb outlet which was about 1/8" thick. It had a 1/8" o.d. tube silver soldered into the side of it over which a 1/8" i.d. vacuum tube would fit. Placed between the carb and the intake manifold it made a "no modification", easy to remove vacuum source. It is surprising how much air flow it would pass. The tube was oriented to make it accessible but not obvious to the eye. The downside was that it placed the carb 1/8" plus the thickness of another gasket behind where it normally sat. The linkages didn't seem to suffer at all.

[WillyR]

For one of my oil pump assemblies I fabricated a plate the size and shape of the carb outlet which was about 1/8" thick. It had a 1/8" o.d. tube silver soldered into the side of it over which a 1/8" i.d. vacuum tube would fit. Placed between the carb and the intake manifold it made a "no modification", easy to remove vacuum source. It is surprising how much air flow it would pass. The tube was oriented to make it accessible but not obvious to the eye. The downside was that it placed the carb 1/8" plus the thickness of another gasket behind where it normally sat. The linkages didn't seem to suffer at all.

I had thought of something like that, but I don't have the machining capability to make one. but that would be ideal.

I would like it to be as unobtrusive as possible that's why I would put it on the backside of the manifold.

she's not going to be a points car, but she is one in 15 million....

[Jerry VanOoteghem]

Place an ad for an intake manifold that has been drilled for a vacuum port. There are lots of them out there.

[Allan]

Or you could cut the flange off a junk inlet manifold and tap into the side of it bolting it between the carb and your intake

Allan from down under

[WillyR]

ohh man I wish I had a slew of spare parts, but I am only a few months into model t's.... give me time....

[CudaMan]

Maybe install one of these? https://www.mtfca.com/discus/messages/3 ... 89840.html

[WillyR]

one could even make them from fiberboard, but I'd stabilize them in epoxy before permanent use/installation.

[gary80005]

You could put a Model A Intake and exhaust on it like I have. The model A intake has a vacuum port right in the middle that I use for my Wolf Whistle. It does affect performance when I use it but it's usually in a parade or at a pretty girl on the side of the road. It improves the performance of my T in Colorado's high altitude. You would need to fabricate carburator linkage and use a different updraft carb. I'm not a purist but I like to use period correct modification. The Model A Intake, exhaust and carb were on it when I bought the car with my dad in 1961. It also had a distributor, milled head, and tractor valves, and also enlarged intake ports. Rumor has it it was in the Tin Lizzy Derbies in the 30s and early 40s. Does anyone have and information about the Tin Lizzy Derbies? In Colorado some of them were held at the State Fair 1/2 mile horse track in Pueblo. Sorry about the rant. I hope you found it interesting.

[gary80005]

You could put a Model A Intake and exhaust on it like I have. The model A intake has a vacuum port right in the middle that I use for my Wolf Whistle. It does affect performance when I use it but it's usually in a parade or at a pretty girl on the side of the road. It improves the performance of my T in Colorado's high altitude. You would need to fabricate carburator linkage and use a different updraft carb. I'm not a purist but I like to use period correct modification. The Model A Intake, exhaust and carb were on it when I bought the car with my dad in 1961. It also had a distributor, milled head, and tractor valves, and also enlarged intake ports. Rumor has it it was in the Tin Lizzy Derbies in the 30s and early 40s. Does anyone have and information about the Tin Lizzy Derbies? In Colorado some of them were held at the State Fair 1/2 mile horse track in Pueblo. Sorry about the rant. I hope you found it interesting.

[WillyR]

I ended up putting a 90* on the backside of the intake.

It's not visible except for the vacuum hose, if I were to plug it, at the 90 or with the 90 removed. it would not be visible at all.