Electric fuel pump, regulator, and fuel pressure gauge upgrade

PwrWgnWalt · February 01, 2015, 10:01 PM

Having read other posts about installing an electric fuel pump and removing the tired old mechanical pump, am close to a decision... Will keep a log here of the process.

Some notes thus far:
There are numerous external (outside of the gas tank) electric fuel pumps available. While many tout large gallon-per-hour ratings of anywhere from 80 to over 140 gph, there are many pumps with 1/4" or even 1/8" inlet & outlet sizes. I am going to opt for a pump with 3/8" line sizes. That leaves me with something like the Holley 'Red' pump (or 'Blue') as a logical choice, and several members report this works well. The 'Red' is rated at 97 gph at 7psi, and 67 gph at 5 psi... plenty of fuel for my 440 at max throttle.

The Edelbrock 1411 carburetor must have no more than 6.5 psi of fuel pressure, per their website, so I will run a pressure regulator after the pump (before the carb).

To monitor the actual, 'running down the road' fuel pressure, I will install a gauge on the dash. It will be an electric gauge, because it is an inherently bad idea to run a pressurized fuel line into any vehicle's interior

(A viable option could be a mechanical gauge with a fuel isolator, but the isolators are not cheap)

2-2-15 update: forgot to mention that I plan to use an oil pressure safety cutoff switch, and a relay setup.

Anyone running an electric fuel pressure gauge, or other input/experience to offer?

kenwautoone · February 02, 2015, 12:06 PM

I just did what u are about to do.first off I been a racer my whole life,holley regulators have a tendacy to creap up on fuel pressure.that holley pump is way more pump than u need.carter makes an electric pump with built in regulator for about 90.00 dollars in summit
Or jegs catalog.pep boys can order it for you.pump comes with 3/8 fittings and install hardware.I put this in 72 Winnebago with 413.

PwrWgnWalt · February 02, 2015, 03:30 PM

Thanks Ken...

There seem to be a long list of the external, canister-type, rotary vane pumps available from Carter.: 18 psi, 8 psi, and 6 psi, 100 gph or 72 gph, with 3/8" or 1/4" in & outs. The Carter P4070 seems to be decent choice. Which one are you referring to?

I do see they claim an internal regulator, but I am unwilling to rely solely on a supposed internal limiter, without verifying the psi it will produce on my setup (part of this comes from several 'ratings' posted by users who state all sorts of different psi readings). Sounds like Carter is a good choice, for both ruggedness and price, but I still need a regulator...

kenwautoone · February 03, 2015, 01:35 PM

I did use p4070.I have used this in many motorhome applications,replacing holley set ups.external regulator was never needed.don t forget to install clear fuel filter .hope this helps

PwrWgnWalt · July 04, 2015, 01:42 AM

After much research and thought, have decided not to install an electric fuel pump just yet. Cost was one factor, reliability another. Instead, I am restoring the existing fuel system to "new", with new fuel lines throughout and a new manual fuel pump. Then, if I need an electric primer pump, it can be added later. A big factor here is the Edelbrock Performer (a.k.a. AFB) carb installed on the 440-3... It must not get more than 6.5 psi, or it floods and runs poorly.

So, first I dropped my front tank (on the Beach-Craft, this is the auxiliary tank), cleaned it out and replaced the old 5/16" rubber line from it to the nearby fuel selector valve. Rear tank will be next.

Was going to replace the aged manual fuel pump with a 'stock' unit, and here's where things got incredibly interesting! There are a multitude of big block Mopar fuel pumps out there, and they are all different in either their inlet/outlet placement, or their psi/gph. Wanting to keep things as simple as possible and not have to use a regulator, I began to look for a fuel pump that would provide less than 7 psi, and at least 35 gph... here's what I found, since our OEM MS6775 (for 1977 440-3) is not available:

fuel pump #. PSI. GPH
M3672. 5.5-6.5. 120. *closest I could find to meet need
M4434. ? 33
M4589. 4-5.5. 20
M4845. 6-8. 33
M4862. 8-9.5. 43
M6191. ? 30
M6774. ? 33
M6935. 5.5-6.5. 29. * another possible choice
Ed1723. 6. 110. * went with this one for simplicity
Hly12-440-11. 6.5-8. 110
MP P4007039AB 8.7. 80

Since I have the Edelbrock carb, I ended up going with the Edelbrock 1723 manual fuel pump, which does not need a regulator since it runs at 6 psi/110 gph. I did have a little difficulty finding the correct 3/8" NPT connections to the pump (they are not the regular pre-made fuel line connectors), but had that solved in short order.

TripleJ · August 18, 2015, 06:29 PM

In my opinion you made the best possible choice. I messed up when I cheaped out and went with the 'factory replacement' fuel pump, then was forced to install a pressure regulator to feed my edelbrock carb. Multiple pumps, high performance electric pumps, etc. are unnecessary.

Now the trick is finding an accurate and not-too-costly remote fuel pressure gauge setup. I still believe it is important to know.

PwrWgnWalt · August 23, 2015, 12:53 AM

Busy summer, but not because I'm getting to play in the MH...
TripleJ - found the used Autometer Fuel Pressure Gauge (electronic) on eBay for $78, included everything needed - gauge, sender, wiring harness)

Did manage to snap this picture of the new, additional gauges to monitor the engine.
Still have to finish the install - but first need to determine the final location for the 3-gauge pod.

From left to right:
1. AutoGauge (by Autometer) Vacuum gauge
2. Autometer electronic Fuel Pressure gauge (reading just over 6 psi with the new Edelbrock fuel pump)
3. PLX DM-6 with Wideband Air-Fuel Ratio SM-AFR (4th Gen) (does all sorts of neat things -
system voltage, graphs, diagnostics; all on a touch screen) It is reading the AFR here.
Just a tad rich, but good to know what's going on!

DRMousseau · August 23, 2015, 05:27 PM

LoL!!! forgive my giggles,... but photo above caused me to reflect days looong past. The days of big block performance and monitoring all systems to preserve my investments. Watching fuel pressure, volume and boost was a necessity when running nitrous and blowers back then. But not so much today, as electronics monitor and prevent the mishaps we so feared in those days. We don't even need a tach much anymore.

At 60mph, 10mpg,... its easy to see that a 6gph pump is minimal for our needs. Some of the old carbs were notorious for flooding, even with simple gravity fed fuel systems. Still, I've not ever seen a need for much more, in big block trucks, than a basic 30-40 gph, 3-7psi regulated electric fuel pump located as near to the source as possible. Liquid pumps are far more efficient at "pushing" fuel, than "drawing" fuel over distance. They are my preference. Engine based mechanical pumps have a LOT of work to do. Get the best you can if this your desired option.

Still,... the thought of a nitrous injected Winnebago is sure tempting!!! LOL!!!

HamRad Mobile · October 25, 2015, 12:21 PM

Good morning, DR Mousseau;

OK, yes, this is going back a while. I am trying to determine if one of my old memories is still valid.

Nitrous Oxide, N2O; 2 pounds per minute plus sufficient fuel (a lot!) to insure that the N2O combined with the fuel instead of the tops of pistons, the edges of exhaust valves, et cetera, equals 100 horsepower.

Is that memory still basically correct?

I seem to remember that a 20 pound grey cylinder was good for about 10 minutes of "enhanced performance."

Enjoy;

Ralph
Latte Land, Washington
and the 1987 Winnebago Elandan WCP31RT,
which is still being "modified"