EFI pump regulated to carb?

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joe 90
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Re: EFI pump regulated to carb?

Postby joe 90 » Sun Aug 20, 2017 3:49 pm

As a generalisation, turbo jappers, 255 litre / hr pump stock supply and return lines give no problems.
Usually 8mm supply, 6.5 mm return.

azhatchback
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Re: EFI pump regulated to carb?

Postby azhatchback » Mon Aug 21, 2017 9:06 am

I use this with a 340 lph in tank pump on a return system with no issues at 6.5 psi.

https://m.summitracing.com/parts/aei-13204

I also have it mounted on this for my Holley ultra HP. They make several versions of the log for different carbs and even an all in one kit.


https://m.summitracing.com/parts/aei-14203

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Re: EFI pump regulated to carb?

Postby azhatchback » Mon Aug 21, 2017 9:25 am

Oh ya I also have it all on 6an lines and fittings, both ways. That reg is really nice if you don't need the log. 1 feed, 1 return, 2 carb feeds for each fuel bowl.

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Re: EFI pump regulated to carb?

Postby 77cruiser » Mon Aug 21, 2017 11:25 am

I ordered this regulator, & will be using -6 feed & return lines.
https://www.summitracing.com/parts/aei-13301/overview/
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Re: EFI pump regulated to carb?

Postby 427dart » Mon Aug 21, 2017 2:49 pm

Why do you need an electric pump? A really good mechanical pump should work well up to 750 HP...such as in a Nascar type mechanical pump.

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Re: EFI pump regulated to carb?

Postby 77cruiser » Mon Aug 21, 2017 3:57 pm

I'm trying to feed a Qjet.
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Re: EFI pump regulated to carb?

Postby BOOT » Wed Sep 06, 2017 12:53 pm

As Joe said basically use two regs with efi pump for carb https://www.aeromotiveinc.com/product/e ... regulator/
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Re: EFI pump regulated to carb?

Postby mark_follweiler » Wed Sep 06, 2017 2:16 pm

almost any good return style regulator will work. have done many carb conversions, never any problems.

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Re: EFI pump regulated to carb?

Postby Fireonthemountain » Thu Sep 07, 2017 12:01 am

The real and simple answer to me is probably a good flowing mechanical fuel pump for about 30-40 bucks pulling thru the electric pump, with it off. No hot fuel, or hot electric fuel pump nor noise. A switch to turn it on, for so many seconds and then back off again, in those road warrior or world championships finals moments. Its been done for more decades than most remember. One more way things can be done.

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Re: EFI pump regulated to carb?

Postby stealth » Thu Sep 07, 2017 8:27 am

Put the return regulator close to the tank, then regulate to normal PSI to to carb.

Short large return hose right into tank.
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Re: EFI pump regulated to carb?

Postby 77cruiser » Fri Sep 08, 2017 7:49 am

Have it installed works fine. 3/8 pump to reg, 1/2 return, set at 6 psi.
Jim

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Re: EFI pump regulated to carb?

Postby kimosabi » Fri Sep 08, 2017 8:52 am

I use the RobbMC regulator for my qjet. A big return line is a must running that low pressure. The volume going through the return is nuts when you restrict that much flow.

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Re: EFI pump regulated to carb?

Postby cjperformance » Fri Sep 08, 2017 6:59 pm

77cruiser wrote:Have it installed works fine. 3/8 pump to reg, 1/2 return, set at 6 psi.


Good stuff, yep big return line is just the simple no fuss way of doing this setup
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Re: EFI pump regulated to carb?

Postby carmakerevive » Sun Sep 10, 2017 10:16 pm

427dart wrote:Why do you need an electric pump? A really good mechanical pump should work well up to 750 HP...such as in a Nascar type mechanical pump.


Electric pump is reliable, neat and easily replaced. Cable driven pumps as reliable as they are, are tricky to plumb and complex to run the cable etc. (for a waterman or kinsler style one which i would class as a really good one). If you buy a cheap pump, you do get more leakback through from the high pressure side into the low pressure side on an electric pump than you do with an expensive elec or mechanical one with tighter tolerances. which means vapor bubbles up the lines and into the carb. not as much of an issue with carb as it is with EFI though as it can vent out from the float bowl.

Anyway, as said... getting a good PR valve is important. As someone said you can run two, this will work - i've heard Kinsler mention it numerous times. and a big fat return line always.
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Re: EFI pump regulated to carb?

Postby joe 90 » Mon Sep 11, 2017 1:02 am

Electric pumps are far easier to fault find with.
Don't even need to run the engine to test pressure and flow rate.


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