[Formulajones]

All this talk for goatracer and all over a mechanical pump that makes too much pressure?? Just a stock 389??

Sounds to me like you just need to find a good mechanical pump. Rigging up an entire fuel system just because you have a faulty mechanical seems like a bandaid for the actual issue.

It can't be just me but I haven't had a stock style mechanical make too much pressure. Ive only had them not make enough. And I still have a half dozen cars here that run mechanicals.

If it were mine I stay away from carter, air tech, AC, and all that stuff that looks like stock cheap pumps because that's what they are.....cheap i either run a robbmc or I buy the summit brand pumps. The summit pumps that are around 60 gph only make 7-ish psi and work fine on stock and mild engines. That would be super simple and way easier solution and not have to cobble up the fuel system with add on stuff

[Formulajones]

Originally Posted by Squidward

True. But how will I hold in all the water that leaks past the trunk seal?

Lol that's a different problem

In all seriousness if you don't want an access door it's not the end of the world. The chances of a pump failure and dropping the tank are pretty slim. A good walbro which is what the OEM uses will go for 10+ years and more than 100,000 miles and in many cases much longer than that. Zillions of new cars everywhere and people don't even think twice about it.

Out of 4 cars here with in tank pumps for many years I only had to replace one. It was in service for maybe 4-5 years I think, and it showed signs, low pressure, sounded a little funny, but never quit or left me stranded. I have an access door on that one. Swapped in a pump pretty quickly. That's been 3-4 years ago.

[Formulajones]

Just another example I just finished building a 450hp 383 SBC for my G-body with the intent of driving it regularly.
Kept it simple, carb and mechanical pump. I used a summit brand 60-80 gph pump that was around $80 I think it was. Works perfect. 1000 miles on the combo so far, no long cranks, fires right up, no hot start problems, and keeps up with the engine to 6000 rpm.

[PontiacHO]

Ok shoot me…Edelbrock mechanical fuel pumps are low PSI pumps to mate up with their carbs…

[78w72]

x2 on the edelbrock mech pumps, had one on a 500+hp 467 that ran fine on the street and low 12s at the track, ~7psi ran deadhead. Changed to a robbmc and still run deadhead with no issues. After sitting for about a week it does require some short cranking to fill the q-jet bowl thats gone dry from either evap or drain back but just a couple 3 second cranks & it fires right up, not really a concern but I do want to go intank pump to avoid that & have better fuel supply.

Buying a better mech pump will fix teh psi issue but could still have the hard starting after sitting, the easy way to address that is to buy a low cost mech pump and run it inline with the mech, after sitting for awhile you just flip a switch to prime the system & it will start right up. There are pumps that will flow fuel when off, think carter makes one for low cost, and there is a diagram in a few older threads on here from a guy that shows how to make a bypass set up to go around the elect pump when its off. Do some research on that set up to deal with the hard starting instead of trying to back engineer a OEM intank pump or spend $500+ on a tanksinc type full in tank system.

[Goatracer1]

The noise I was complaining about was not from the Mechanical pump but the Electric pumps that I have used in the past. The OEM pumps from the 1970's-1980's for carb cars are too big in diameter to fit through the opening in the tank. The earlier cars have a much smaller opening for the sending unit. Thanks for the options and I will consider them.

[Goatracer1]

I have read several articles about replacement mechanical pumps making too MUCH pressure. The recommendation was a Robbmc pump but that is expensive and a bit of over kill for a stock engine. I was not looking to rebuild the fuel system. I was looking for an easy fix that is why I was considering an in tank OEM pump but I found that one would not fit through the opening.

[Formulajones]

An in tank pump is not an easy fix nor is it cheap.

The easy solution is using a mechanical pump that works right. While a good one may not sound cheap, it's cheaper than a proper in tank setup.

The smaller robbmc pump, while maybe overkill for a stock engine really isnt the point. It's quality and reliability that is the main concern and you get that with the robbmc pump. There isnt much that's cheap about these cars anyway. Reliability rates higher in my book even if I have to pay 3 times as much.

I guess you just have to decide what's more important to you and roll the dice.

The summit pumps I mentioned are perfectly fine and cheaper. Still overkill for a stock engine but.....

Edelbrock/Holley pumps also work, some of which are rebuildable too like the robbmc which is another nice benefit.
You have a lot of options aside from electric stuff

[Shiny]

Originally Posted by Goatracer1

I am looking for your ideas for an electric fuel pump. The car is a totally stock 389 1962 Bonneville. I don't need a racing fuel pump. I want to get rid of the mechanical pump. It makes too much pressure. Besides the car is parked a week or 2 without being started and requires a lot of cranking to get fuel to carb. I've had electric pumps in the past and they have been very noisy. Does anyone sell a universal in tank pump for a carbureted engine? Thanks for your time.

This sounds like 3 goals.

1st is reducing pressure at the carb.

2nd is filling an empty carb (priming) to avoid extended cranking.

3rd is solving the 1st and 2nd without adding annoying noise.

It seems you may be prioritizing the priming goal since you want an electric pump. If so, there are lots of recommendations in the thread.

If you are willing to just fix the overpressure and continue accepting the empty carb hassle to save money, I think you might be OK with an inexpensive aftermarket mechanical pump.

Since you state the current pump generates too much pressure, does this mean you have fittings to put a gauge at the carb or did you conclude this based on other symptoms, like flooding?

I ask this because it is possible to overpower any needle and seat in the carb inlet. If the needle and seat fail to seal, it will ALWAYS be overpowered. This may be obvious but thought I'd ask...

Personally, if you think the issue is a mechanical pump delivering too much pressure and you can actually measure it, I'd start by replacing the pump and measuring the pressure again. There are many aftermarket pumps that are spec'd at ~7 psi max. I'm an example of buying one of those that delivered over 10psi so I understand and agree it is a crap-shoot and there are trust issues.

But the replacement did NOT overpressure my carb. No, it wasn't anywhere near the quality of a RobbMc but you can buy 4 or 5 at the parts store for the same money and the install isn't difficult. Maybe buy 3 different pump brands, measure the pressure at the carb. When you find one that's not over-pressuring, return the other two... When you find all 3 of them over-pressuring, curse me and go spend more money?

As to electric pump noise, I once had one that rattled a lot. I think it was a cheap solenoid pump. Many of the "external" pumps recommended here are rotary vane designs. Just a guess but seems they'd be far less likely to make noise.

Personally, I still want to fix the priming problem by adding an electric pump in front of my mechanical pump and I think noise would be a good thing. I view it as power the pump, listen for the noise to stop, then crank knowing the carb bowl has been filled. Once it starts, I won't hear the pump and I may even be able to turn it off.

Good luck with all this! All these options add a lot of uncertainty.

Mike

[Goatracer1]

Shiny was exactly right as to my goals. I have been doing this a long time (over 60 years) and some of the fixes that I would have used years ago don't exist any more. How much fuel pressure can I expect a Rochester 2bbl needle and seat to control? What needle and seat assembly is considered a good brand? My 1964 GP has an electric fuel pump that is reasonably quiet but I have no idea what it is. My GTO has a massive Edelbrock pump that can be heard over loud exhaust. I have a very good fuel pressure gauge set that can be installed in series with the carb.

[Jay S]

I once did a pump like Mike and Jack referred to on a Ford Van 351 4Bbl when the fuel pump cam eccentric failed.

We have an old 350 Honda 4x4 ATV which has the fuel tank under the seat that has one of those style pumps. The only caution is all those pumps are not created equal, some aftermarket pumps built to much pressure and can overcome the needle and seat. On that Honda I have, Honda dealers loose there minds and start cursing if you ask to get parts for it because they had such bad experiences from everyone replacing the original pump with cheap aftermarket pumps. The pumps look the same but run a little more pressure when they go out of stroke. It slowly dilutes the oil with gas and created all kinds of trouble. Get the correct pump and it works great. I am guessing the Faucet model Jack has would be what you need. I have completely lost track of model differences.

[Shiny]

Originally Posted by Goatracer1

...How much fuel pressure can I expect a Rochester 2bbl needle and seat to control? ...

I don't know what your carb can handle but this is what the 1970 service manual states for fuel pump pressures:



My car was a 2 bbl so yours is probably similar and the chart above made no distinction between 2 bbl and 4 bbl.

I measured the pressure it took to overpower the needle and seat on my carb and it held up to 12 psi.

It is probably safe to assume your carb is happy with pressure below ~9 psi. Most aftermarket mechanical pumps for a 70 are spec'd with max pressure of 6 to 9 psi. Here are some examples Carter sent me:



It is a fact that some aftermarket carbs will exceed these factory pressures but I don't think they all do. Some will actually do what they say!

Mike

[chiphead]

One thing I've found with external electric pumps is that they don't have an extremely long service life. I ran a Mallory Comp 140 external pump with a return style fuel system in my other '67. After about 4 years and just a few thousand miles, it had about worn out the brushes. It's a quality pump but you could hear it when the engine was stopped. It was much quieter than the holley pumps of the same era, however. It's for sale cheap in the performance parts section. (shameless plug)

I'd recommend a RobbMC mechanical pump or a full conversion to a Tanks Inc in-tank system. I just installed the RobbMC 550 in my red '67, its a nice piece.

Question while I'm in here. The little gauges that fit on a DP fuel log, can they be trusted if they are NOT liquid filled?

[Formulajones]

Meh, I don't trust those little things liquid filled or not.

Maybe for a quick ball park check when cold but I don't rely on them. Especially after the engine warms up.

Best setup for a mechanical is to get it off the engine, mount it on the cowl, or use a sending unit and mount it in the car, and use a good quality auto meter or something similar.

[KS circutguy]

Their was a reason all AC equipped vehicles had a return line from the pump to the tank.
If not equipped install one.
That includes mechanical or electric conversions.

[KS circutguy]

Originally Posted by KS circutguy

There was a reason all AC equipped vehicles had a return line from the pump to the tank.
If not equipped install one.
That includes mechanical or electric conversions.

.....

[Goatracer1]

From the info Shiny supplied my needle and seat should be able to hold the pressure the pump is putting out. The N & S are from an Ames kit. Is there a better pair to use?

[Shiny]

Is it flooding?

If so, have you measured pressure at the carb inlet to know what your pump is delivering?

If I were looking for parts, I'd call Cliff.

[sdbob]

I have Cliffs accelerator pump in all my qjets for the fuel available. I ran a small electric pump in my SD for 30 yrs before it gave up. Now I a Robb Mc mechanical pump. Going to put it on,as soon as I get to figuring out what fittings I need to make it look stock. The pump is bigger.