I'm in the process of getting a little Crosley back on the road. I'm going with a 6v electric pump. Now I need to keep the pressure down to 1.5-2 psi, or that tillitson will puke! I found this thread here https://www.jalopyjournal.com/forum...ake-their-own-fuel-pressure-regulator.319672/ Here is my version, with it returning to the tank. I'm trying to eliminate vapor lock... Have a look: Did I do this right?
Ohh, I just read the link. I see what you are thinking. I haven't any idea if that will work. I usually use a Holley 12-804 that has the return tee built in and is adjustable to 1 PSI.
Sorry, I should have said my plan in the text. Basically to use a byp*** pill holder, to act as a return & pressure regulator. I've used those 12-804's before. Here lately the quality has been hit or miss... The pump is a Carter p4259 6 volt- vein/rotor style. Puts about about 6-7 psi, at 70+ gallons per hour.
The problen I see is that the "pill holder"isn't really a regulator. As fuel flow through the carb increases (under load) the pressure will decrease. At idle it will increase. If you use a real reg and run the byp*** to the tank it should work.
Ah, that makes sense. I always thought those 12-804 holley 1-4 psi weren't made for a return, though it has 3 ports.. I guess it depends on the flow of the pump. Should have plenty of gph then. I can hold the engine block under one arm!
FYI the thread you shared has comments from Gary Terhaar. True hot rodder and an old friend of mine who p***ed away last August. Not sure why I needed to say that… but reading his words made me hear his voice one more time
The tee needs to be as close to the carb as possible, and the regulator should be near- you want the least amount of pipe on the car possible under pressure of gasoline, for safety's sake. The return to the tank should be zero obstruction after the regulator. It should cycle the fuel quite well. Phil
I was thinking of putting the regulator on a inner fender. I don't want it dangling above everything. No need for a tee then.
Sorry , brain fart. I used a Holley 12-881 I think it was with the return but they only go down to 4.5 PSI so I used a 12-804 in conjunction with it. My bad. I don't know why they don't make a return style reg with 1-4 PSI.
I had that idea too, which it would work fine, but just more things to go wrong.. Probably Holley thinks most super low psi stuff will be with a mechanical, or low flow pump.
Building a low pressure, low volume system, you really do not need a return line. A lot of effort and some money, really for no gain. If you had a high pressure pump, along with it being high volume, then yes, absolutely use a return system. Mike
I've had enough vapor lock issues, to demand a return line setup. Seems to happen on slower, small stuff. In the middle of a mountain range.
Your drawing looks a lot like the setup for Hilborn fuel injection. I guess it would work if your "pill holder" was a 1.5 - 2 psi check valve. It would have to be sized to handle the max volume of the pump output.
I used a Holley jet in the return line, this was using a TBI in tank pump that is rated around 36 lbs. Had it hooked up to a 305 with a Holley four barrel. Took a little playing with the jet.
The "pill holder "you want to use is actually a low speed or idle by-p***.The spring on the poppet valve controls the minumum pressure and the pill controls the maximum pressure.Use them all the time when running a Hilborn pump with a carburator
A stock good condition fuel pump will work fine, keep temp under 180°, take engine side covers off and get all the crud out of the water jacket. Service Motors in NV has fuel pumps.
You should be aware that there are counterfeit knockoffs of the quality components, so when you see one from a less than well known distributor for a cheaper price........its often a knockoff. Your pump is going to operate at more than 1 psi and the regulator will drop that pressure to 1 or whatever you want. With a low pressure like that I would mount the regulator near the carb and run a return back to the tank. Your pump will appreciate the return line and last longer.
Don't even need that Tee. Just put the regulator in where you show the Tee, and then use the 2nd outlet to connect to the return line. Simple.
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