Can anyone tell me properly how to set up an enderle carb bypass check valve. I tried to call enderle (no answer) and another enderle dealer with no help. I know most use the new style internal regulated pumps,APD and BLP style now. Mine also has a place for the bypass pills in the end. I’m currently using a 10 pound spring with no pill, back to tank, with a deadhead regulator at the carb. It works but just chasing rabbits on my entire setup looking to better myself with what I got.

First off I'll assume you have a belt driven pump. If it's the brass poppet by pass setup, the internal spring controls your idle pressure and the pill in the end controls the maximum pressure. You don't need/use a regulator with this setup. You want 2-3 psi at idle obtained by adjusting the spring and 9-10 psi at wide open throttle (Maximum RPM). Idle pressure can be adjusted by clipping the spring length if it's too high and perhaps stretching it if it's too low. Depending on which pump you have (Most use the 80A-0) I would start out with a 140 pill in the return and make adjustments from there. Hope this helps. Kevin

Undertaker thanks for replying, i have a 80a belt drive with no marks on pump which i was told when i bought the car is a 7 GPM. Back Story: When i bought,turn key dragster, it was set up just as you described. I still have spring and pill that was removed plus extras i purchased. No idea what was originally in it. So i started having carb trouble and we thought it was the pump and pressure issues and i simply got rid of alcohol carb and replaced it with a good new GAS carb. On bypass i was was told to set up as first post and it has been this way for a couple years. I now feel like my setup is wrong and would like to fix it properly. Do stalling against convertor get me close enough to race it and then adjust or does it need to be flowed and set on a bench?

First off I would not use a dead head regulator on anything, ever. Especially with gas because of possible vapor lock.

If you run a .140 main jet in there I think you may end up with 50 to 100 PSI or more so at the other regulator which may not be able to handle that. At idle probably no problem because pump may only be putting out 3 or 4 PSI.

Do not know what regulator you have but I think you should look at complete fuel system.

Basic Enderle bypass valves have a small spring and use spacers to fine tune them. They have different springs. We do not know what springs you have in there. Do you even know what pressure you have at regulator or at the carb?

First I would try to find out what actual fuel pressure is at carb and regulator wide open. Then determine what to do from there. Until you do that it is just a guess. We do know that pump if it is the 7 GPM is way more fuel than that motor could ever use and will be returning probably 90% of it back to the tank. So you need a good return system with no restrictions.

Pressure leaving pump going to regulator is 10psi. Pressure out of regulator is 7 1/2. 10 pound spring, no shims, no pill. Car runs 5 flat with no issues, constant, dialable, etc. BUT I’m conserved with my possibly too small regulator and foaming the fuel AND the possibility of going back to a alcohol carb.

quote:

Originally posted by Curly1:
First off I would not use a dead head regulator on anything, ever. Especially with gas because of possible vapor lock.

I didn't get the memo and have been using a dead headed regulator on my cars for 30 years, on gas and not once have I experienced vapor lock.

Curly

Ed is correct regarding your dead head regulator statement. If you have vapor lock issues using one then the cause is due to the routing of the fuel line that's way to close to heat sources. Adding a return style regulator to correct this problem is a crutch and not a fix.

For what we do, there is nothing wrong with DH regulators.

TOP38...KNOWS

quote:

Originally posted by JPosey:
Pressure leaving pump going to regulator is 10psi. Pressure out of regulator is 7 1/2. 10 pound spring, no shims, no pill. Car runs 5 flat with no issues, constant, dialable, etc. BUT I’m conserved with my possibly too small regulator and foaming the fuel AND the possibility of going back to a alcohol carb.

As stated above there is no reason to run a pressure regulator with enderle deal. For gas, at WOT, with the right size needle and seats, 6 PSI is more than enough.

For alky, this deal was used to crutch the real problem of high HP motors and too small needle and seats (one carb deals) so to fix the issue they raised the WOT pressure up to 10 -12 psi to achieve the required fuel flow.

Fuel aeration is due to having too much fuel pressure which causes aeration once the fuel exists the needle and seat into the bowls. The lower the fuel pressure you can run, the better.

I run a single gas 632 making over 1200 HP, I run 5 PSI at WOT!

I can see where curly said about pump being too big and bypassing most fuel back to tank. I want to remove regulator and let check valve do the work if possible. So should order new 3lb spring and shims and adjust with pills or should I just use 6lb spring and shims if needed and just use that to control all the fuel?

quote:

Originally posted by JPosey:
I can see where curly said about pump being too big and bypassing most fuel back to tank. I want to remove regulator and let check valve do the work if possible. So should order new 3lb spring and shims and adjust with pills or should I just use 6lb spring and shims if needed and just use that to control all the fuel?

I would use the 6 lbs spring and shim as needed. You can make a leakdown type tester to set it with.
As for pump being too big do not worry about that, better too much than not enough as long as you have adequate return. Also make sure the return does not spray right onto or near tank pick up.

On my setup I run a Enderle 80a pump with a “carburetor” Enderle shutoff bypass. They are completely different that a regular enderle bypass shutoff. If you go on Good Vibrations website and look at enderle 3 way shutoff as you scroll down you will come to one for carburetors. No brass pill/spring valve in it. Then I run a return regulator on the far end of the fuel log. I have a racepak so I get actual data my entire run. 5 lbs at idle and around 8 going down track.
Hope this helps.

Posey,
undertaker had it correct.
Don't make it harder than it needs to be.

Can it be done on car at track or sent somewhere to be flowed pressure and set on a bench?

Do it in your driveway.
Install a pressure gauge.
Install a 3B spring
Install your largest jet.
Start car
Note idle pressure. If you have any you are good. It doesn't take spit to run at idle.
Raise rpm
note pressure at your chosen rpm.
If too low, install smaller jet.
and so on.

Thanks Dave Koehler

Most welcome.
I should add that when you do the higher rpm test bring up the rpm at a reasonable rate, don't rap it.
Watch the gauge.
The pressure will climb with rpm.
If it reaches a point where it more of less levels off that is your current high pressure point.
Too low, reduce the jet.

I just went to this exact setup on a small 250 blower (1250 hp?) and an 80a-1. What’s a good starting point on the main pill? Largest I have is .170 but I have half a dozen smaller pills and a drill index patiently waiting on the bench.

The .170 was around 7psi at 4000 engine rpm in park no load, pump speed at 50%.

I’ve not ran it yet, just annoyed the neighbors running it in the driveway so far.

7 lbs is good for a carb.

I’m just concerned it’ll have upwards of 12 at high rpm. I don’t currently have a racepak but plan on tossing on a GoPro to the gauge so I can know for sure.