Does anyone know how many ounces of fuel it take to fill the fuel bowls on a 1973 Thermoquad carburetor? Can the bowls be filled through the vent tubes to avoid lots of cranking after the car has sat for awhile?
Carter Thermoquad fuel bowls
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70bigblockdodge
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Yes, though the 2 tubes in the rear or the single in the front, they hold quite a bit of fuel, guessing about 8-10 ounces.
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My guess is more like 3 ounces depending on float heights.
Gold Rush
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I agree. 3 oz. in each tube is more than enough to wake up the beast. I switched to an electric fuel pump maybe a year ago. Added a live 12 volt feed that I run a minute or so before cranking. Haven't had to pour gas down the vent tubes since.
3 ounces in the front vent did the trick to waken the beast. Thanks
This:
Available in either 5/16" or 3/8" fittings. I install these along with a toggle or momentary switch under the dash on all my cars with a carburetor. The problem is today's gasolines have a lower Reid Vapor Pressure number because they are formulated with more aromatics and lighter base stocks to increase volatility making them vaporize more quickly which modern fuel injection systems require. The problem is when you switch the engine off the fuel in the bowls of a hot carburetor begin to boil off and if the car is not started again in a few days there is no fuel remaining in the carburetor for a restart so you will have a long cranking time getting fuel back up to the carburetor. The answer is switch your in-line fuel pump on for a few seconds to refill the carburetor for a quick restart.
Carter Fuel Systems In-Tank Universal Electric Fuel Pump Automotive Replacement 12V (P60430)
Available in either 5/16" or 3/8" fittings. I install these along with a toggle or momentary switch under the dash on all my cars with a carburetor. The problem is today's gasolines have a lower Reid Vapor Pressure number because they are formulated with more aromatics and lighter base stocks to increase volatility making them vaporize more quickly which modern fuel injection systems require. The problem is when you switch the engine off the fuel in the bowls of a hot carburetor begin to boil off and if the car is not started again in a few days there is no fuel remaining in the carburetor for a restart so you will have a long cranking time getting fuel back up to the carburetor. The answer is switch your in-line fuel pump on for a few seconds to refill the carburetor for a quick restart.
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Todays lower Reid Vapour Pressure numbers in gasoline mean that the fuel will actually evaporate slower. A lower number doesn't mean that it takes less pressure to evaporate, it means that less pressure is developed by evaporation at 100 °F. The reason for the lower Reid numbers is to reduce evaporative emissions during refuelling or other instances of when the fuel isn't contained by a sealed tank or vessel. Modern fuel injection results in a finely atomized spray which mixes and burns quite easily with these lower RVP numbers.
Low Pressure, often called 'summer mix' gasoline can be examined in more depth in these articles:
Motor Vehicle Fuel Programs in Texas
Information and links to Regional low RVP gasoline, Texas Low-Emission Diesel (TxLED), and El Paso fuel programs.
www.tceq.texas.gov
Thanks for the correction!
72sunroof
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If it is sitting and doing this fix the primary transfer caps with JB Weld Marine. Sounds like it is leaking out through the seal that connects them to the main body.
Hopefully you are using non-ethonal gas since X rings are not ethonal resistant.
And yes get a squirt bottle and squirt(slowly) about 3 oz in each side.
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