[Rugratman]

I have gone thru 3 replacement pumps. The latest one from carter is pushing 11 lbs. Ugh.
So I have installed a regulator. But it is ugly.
Any suggestions on hiding one.

I bought this replacement pump from Ames so I wouldn't need one.

[steve25]

And this is the pressure your reading on a mechanical gauge, or a electric?

[Rugratman]

3 different mechanical gauges.

[steve25]

And all 3 pumps are flooding out your carb at idle?

[Dick Boneske]

Ames has a pump rated for 6 psi, which would work. Talk to them.

[Rugratman]

I bought that pump.
It's pushing 11 lbs

I bought a edelbrock pump too, that is at 9 lbs.
I wanted to use a stock pump -no return- so I wouldn't need a regulator.

[78w72]

Originally Posted by Rugratman

I bought that pump.
It's pushing 11 lbs

I bought a edelbrock pump too, that is at 9 lbs.
I wanted to use a stock pump -no return- so I wouldn't need a regulator.

i ran the edelbrock pump with no regulator for a couple years on a 467 with a 1978 Qjet, never confirmed the psi but had no signs of any problems related to too much fuel psi. used it on the dyno too, supported about 520 hp. a friend had one for a few years as well, seemed to be a good pump.

Have you considered a robbmc 550 pump? supposed to be rated ~6psi and flows much better than any stock or edelbrock/carter pumps.

Are the gauges liquid filled? if so those are known to be inaccurate if heated up near the engine. what carb do you have?

[Formulajones]

The question would be, and Steve asked, are those pressures causing problems?

I have one here that shows 9 psi on an accurate autometer gauge and the car runs fine.

Typically most good needle and seats won't have an issue holding pressures like that. In fact I kind of prefer it because after you get some heat build up in the system pressure tends to come down anyway so you have some wiggle room without worry of starvation. The same car that has 9 psi now had a stock pump before that was pretty weak with cold psi at just 4 but after it warmed up it had ZERO.
My current summit high output pump does a better job, starting out at 9 psi and still maintains 7 1/2 when warm. Idles and runs down the road fine.

[Rugratman]

Ok, I will try it.
I was afraid it would be too much.
I will let everyone know what happens.

Thanks again

[Formulajones]

Another example of the quality of these pumps today.

As far as ethanol, I've never had an issue with it. My bird for example has a pump going on 25 years old now and still working. Daily driven and for the last 16 years it's had nothing but ethanol based fuels run through it.
As far as I'm concerned it's already run passed what I consider it's normal life span and I should be replacing it anyway as preventive maintenance. I tend to avoid these stock mechanical pumps nowadays so I'll be going to the Robbmc pump when I get around to it.
Better quality parts in my opinion. What these places make today for stock replacement pumps I can't even trust to make it around the block. I went through 3 of them in 2 days on my last go around with those things.

[Rugratman]

So I ordered the high flow more expensive edelbrock pump. It pushed nine pounds. So I then got a carter from Ames which was supposed to be factory correct at 6 pounds. But it's at 11 pounds. Checked with 3 different gauges.

It runs fine with the regulator at 5 pounds.
If I could hid this regulator, I would call it a day. Then I could run any pump, robbmc.

[Formulajones]

You can run the 550hp RobbMC pump without a regulator. It's his bigger pump that requires the regulator.

I wouldn't even worry about regulating pressure down from 9 psi if that's what you're seeing. Most carbs, if they have a decent needle/seat assembly in them, will hold those pressures without issues. If it's having running problems and you have to regulate it down to 5 psi to run right, I'd likely be changing the needle and seat and possibly the float setup for something a little better. If it's a Q-jet I'd contact Cliff for the parts.

[78w72]

Originally Posted by Formulajones

You can run the 550hp RobbMC pump without a regulator. It's his bigger pump that requires the regulator.

I wouldn't even worry about regulating pressure down from 9 psi if that's what you're seeing. Most carbs, if they have a decent needle/seat assembly in them, will hold those pressures without issues. If it's having running problems and you have to regulate it down to 5 psi to run right, I'd likely be changing the needle and seat and possibly the float setup for something a little better. If it's a Q-jet I'd contact Cliff for the parts.

Only recently in the last year or so the robbmc 1100 pump was changed to be non adjustable, all the ones before that were adjustable down to 7psi and didnt need a regulator on mid to late 70's Q-jets. I run one on my 467 and have turned it up to ~9-9.5 psi with no carb flooding issues, have since installed a regulator for when I want to turn it up to 10+ psi at the track for more flow, for street i turn it down to lower psi and run the reg at ~6.

The edelbrock pump ran deadheaded worked fine on this engine for street use, but had starvation issues at the track starting at low 12's.

[Shiny]

What about turning your regulator up and see if it makes a difference?

I posted before, but I measured my QJ and it held 12 psi (on the bench) before flooding. I did this by pressurizing the inlet and turning up a regulator until the N/S was "overpowered". After that, I wasn't worried about 8 or 9 psi.

BTW, Kenth warns higher pressure can change tuning, I assume by slightly raising the float level, but that's different than flooding.

[Formulajones]

Originally Posted by Rugratman

If I could hid this regulator, I would call it a day. .

With a mechanical pump in place, it becomes a challenge to hide a regulator. There just isn't much room between the pump and carb with a relatively short distance to cover..

Your only hope would be mounting it next to the pump down low and if you have power steering it would help to hide it a bit. It'll start getting tight with the fuel pump already there.

When I run a regulator and hide it, on Pontiacs specifically, it's because I'm running an in tank electric pump. That leaves the mechanical pump area open with more room, so I mount my regulators there where they can't be seen (power steering) and then run a bent and flared steel line from the regulator to the carb as it would have been with a mechanical pump so the fuel line doesn't give anything away either.

[Dick Boneske]

I know from experience that the maximum pressure a Tri-Power will tolerate is about 6 psi. This is true of all Rochester two barrel carbs model 2G or 2GC.

It’s becoming more of a problem as time goes on, since nearly all aftermarket pumps, including AC Delco, exceed 6 psi, resulting in flooding.

Perhaps someone can come up with a method to reduce the output psi without addin a regulator.

[Singleton]

If the vehicle has a return line, (like an A/C car), you can make your own "regulator" by teeing off the main fuel line between pump and carb and sending some fuel back to the tank thru an orifice. I did this successfully with a tri-power setup, using a carburetor jet as the orifice and a brass tee block. To adjust the pressure, drill out the jet to the needed size. I believe I ended up at around .080-.085" hole and dropped pressure about 2lbs.
Has the added benefit of keeping the fuel cooler flowing thru the pump and lines, and giving the hot expanding fuel somewhere to go when engine is shut off on hot days

[abefromen]

Originally Posted by Dick Boneske

Perhaps someone can come up with a method to reduce the output psi without addin a regulator.

I added a one way check valve between the pump and carb. Don't have the part number in front of me but it was a quality piece made by Dorman. It dropped the pressure by 1.5 psi from 9 without to 7.5 with.