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Discussion Topic:
Vacuum fuel pump, 1927 Lincoln Town Car
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museumguy |
11-08-2022 @ 6:06 PM
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Member
Posts: 8
Joined: Nov 2022
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Our Museum has a 1927 Lincoln Town Car that is used primarily for parades. The V8 engines uses a vacuum fuel system. It seem the vacuum tank is not picking up fuel from the tank mounted at the rear of the vehicle. I have measured the vacuum out of the intake manifold and it maxes at around 13 or 14 inches. It seems this is not enough to properly operate the vacuum fuel tank. Does anyone know of an auxiliary 6 volt vacuum pump that I can install in the vacuum line and supply extra vacuum to the system Any help will be appreciated.
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cliftford |
11-08-2022 @ 8:04 PM
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Senior
Posts: 845
Joined: Jan 2014
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Why not add an electic foel pump?
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museumguy |
11-09-2022 @ 8:45 AM
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Member
Posts: 8
Joined: Nov 2022
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It had one and we could not get fuel pressure low enough. Needs only a pound or so of pressure. Had the pressure regulator blow apart while driving and raw gas went all over engine. Don't know why Lincoln did not burn. Need to stick with vacuum system.
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Dan Duszkiewicz |
11-09-2022 @ 4:46 PM
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Member
Posts: 15
Joined: Sep 2020
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Try posting your question on the AACA Technical forum. https://forums.aaca.org/forum/15-technical/ There is a lot of vacuum tank fuel system expertise there, hopefully they can guide you to fix the original system.
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40 Coupe |
11-10-2022 @ 4:46 AM
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Senior
Posts: 1711
Joined: Oct 2009
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The ideal engine vacuum at idle is 20. The vacuum is a function of how well the engine is running. Suggest you use a vacuum gauge on the engine and adjust the carburetor idle mixture screws, if the carb has them, for the highest possible vacuum and smoothest idle. If the vacuum is erratic the engine could have valve problems or timing issues.
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TomO |
11-10-2022 @ 8:39 AM
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Senior
Posts: 7286
Joined: Oct 2009
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The only 6 volt auxiliary vacuum pump that I could find, would not deliver enough vacuum to operate the tank. 14 inches of vacuum is very low for your engine, suggesting that it may be worn out or improperly tuned. A compression test should let you know if the engine is worn out. The 14 inches of vacuum should be more than enough to pull fuel from the tank in the back of the car to the vacuum tank. Mechanical pumps on cars from the 30's and 40' develop 10" or less of vacuum to suck the fuel from the tank. You either have a restriction in the input fuel system or a vacuum leak in the vacuum tank. A hand vacuum pump can be helpful in diagnosing the problem. https://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-63391.html Connect the pump to the vacuum input of the vacuum tank. Fuel should start entering the tank around 6"- 8" of vacuum. If it takes more than 10" of vacuum to start the fuel flow, you have a restriction in the fuel supply system (rust inside the line, fuel tank venting, debris in the tank, or other debris in a fitting). If you cannot develop more than 10" of vacuum, you probably have a vacuum leak. Here is a link to a topic that gives you places to look for vacuum tank problems. https://forums.aaca.org/topic/292810-vacuum-tank-problems/ If you still have problems, ask questions in the Technical Forums on the AACA site. Let us know how you make out.
Tom
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TomO |
11-12-2022 @ 8:52 AM
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Senior
Posts: 7286
Joined: Oct 2009
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Here is another link to the AACA forum. It contains a copy of Dykes maintenance tips for vacuum tanks and a couple of YouTube videos of a vacuum gauge connected to the fill plug. https://forums.aaca.org/topic/376731-vacuum-tank-questions/#comment-2351248
Tom
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museumguy |
06-15-2023 @ 9:28 PM
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Member
Posts: 8
Joined: Nov 2022
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Thanks everyone for your help. We finally got the Lincoln running. We kept working and fiddling with the vacuum pump and one day it decided to work right and runs like a champ. I appreciate all your help.
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