Will an inline electric fuel pump push through the mechanical pump?

8v-of-fury

8v-of-fury

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I have an issue. My thermo-quad leaks out the secondary wells, yes. I should remedy that, but it just isn't in the books at this moment. I have tried to reseal the wells twice to no avail.

Can I get an electric pump to push through the mechanical pump? I already know it will not suck through it.. whilst using a pump I know will suck un-restricted from the tank on a previous engine.

I basically only want the pump as a primer for when the car sits longer than 20hrs and the carb drains down.
 
They make pumps specifically for that
IMO it will take less time to fix the TQ than to go thru the trouble of installing an E-pump, which should be installed close to the tank, and below the liquid level in it.
@Trailbeast I think, is at least one guy, that has that setup, over on FABO
 
The research I have done so far says yes you can use an electric pump to push through a mechanical. I have seen 4-7psi and 5-9psi electrics. My guess is 5-9psi is what you may want to push through the mechanical. By the time it pushes through 20ish ft of 5/16" line and the mechanical pump and the filter, it should be an acceptable pressure for the float valve to close when it needs to. I can't say for sure on that though.

You say the secondaries? While you may have leak down on the secondaries, I do not think that is the real problem. I saw in the other thread you say it leaks down through the secondaries in 8 hours. Most carbs fill at the top of the bowl. The primaries should not siphon down through the secondaries. Empty secondaries should have no bearing on starting. I think you may be having modern fuel evaporation issues. An electric pump is a solution to empty primaries and the starting issues they present.

I myself am trying to figure whether I want to delete the mechanical pump or just add the electric.
 
AJ/FormS said:
They make pumps specifically for that
IMO it will take less time to fix the TQ than to go thru the trouble of installing an E-pump, which should be installed close to the tank, and below the liquid level in it.
@Trailbeast I think, is at least one guy, that has that setup, over on FABO
Click to expand...

I agree fully, however I have had the carb of two or three times over the years already to try and seal them up better lol. Once was just adding new "sealant" to the existing seal and the other was removing the wells and resealing them fully. I have used this pump before on a diesel with a weak injection pump, as it would lose fuel line prime over night. And fuel prime loss on a diesel is a no-start situation. Anyway, the pump was at the engine sucking fuel 12ft from the tank, and probably 18" higher than the tank too.

I bet I could mount the pump and run wiring faster than removing and tearing down the carb for a well reseal ;)

Hayzoos said:
You say the secondaries? While you may have leak down on the secondaries, I do not think that is the real problem. I saw in the other thread you say it leaks down through the secondaries in 8 hours. Most carbs fill at the top of the bowl. The primaries should not siphon down through the secondaries. Empty secondaries should have no bearing on starting. I think you may be having modern fuel evaporation issues. An electric pump is a solution to empty primaries and the starting issues they present.
Click to expand...

So, in a Thermoquad, there is a fuel bowl on either side of the carburetor fed by one fuel inlet. The lowest point in the bowl is actually the secondary jets, and an epoxy attached "well" on each bowl. When these leak, it will drain the entire fuel bowl.

The electrical for me right now, would purely be a band-aid to help with starts after sitting a day or the likes.
 
Learned something. I guess I never worked close enough to a Thermoquad to notice only one feed. Plus, I assumed the best way to fill was from the top. Way back in the days of the new fangled electronic ignitions when I was learning to turn wrenches, I thought all 4v carbs sucked mixture through all four all the time.
 
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