As above.

When I bought my '64 Dart 225 one year ago, the previous owner, who had had it less than a year, had only replaced two parts:
The coil, and the fuel pump.
He installed a brand-new super-hot-rod Edelbrock coil, which failed within weeks of my buying the car.
He installed a brand-new Delphi fuel pump, which failed a couple of days ago (usual failure mode: "angina carburetoris" – car runs fine up to a certain amount of fuel demand, then runs out of gas).

I bought a new NAPA B0275P pump today, spent the usual amount of time installing it (way too much), turned on the car, fuel all over the place, took apart the carb, all looked fine, hooked up a pressure gauge – 8psi, cranking, with spark plugs installed.

As we all know, the pressure of pretty much every carburetor fuel pump in history is about 4psi (spec. for this one is 3.5-5psi).

That's two brand-new fuel pumps, from two sellers, that are no good.

So, can anyone recommend a brand of fuel pump that is statistically likely to actually function? I do not find removal and installation of fuel pumps amusing.

I'm a bit annoyed right now.

Thanks,

– Eric

Are you installing a mechanical pump or an electric pump? If electric, why?

Donno where you picked up this factoid; it's plain ol' wrong. It's also not relevant to a question of what fuel pump you should buy.
That's two of the same Chinese-dreck fuel pumps in two boxes with different names on them.

"New" is a problem in this case. New \6 fuel pumps tend to be much poorer quality than we used to be able to get. If you go too far the other direction, old fuel pumps pose risks as well—rubber doesn't react well to age, and some of it doesn't react well to alcohol in the fuel. There is no guarantee, but you could scarcely do worse than you already have, and I had consistently fine results buying and using NOS AC № 6972 fuel pumps. Cheap and easy on eBay, such as this.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

I did say "factory-type."

– Eric

Every factory carburetor fuel pump that I can recall seeing is spec'ed at about 4psi.
Early cars (Model T, Model A) had gravity-feed fuel supplies. When they went to newfangled fuel pumps, it was simplest to keep a gravity-like fuel pressure so as to be able to continue to use the same carburetors, rather than redesigning them.
If you can tell me any salient outliers off the top of your head, I'd be grateful, and would retract my boneheaded statement.
If not, my boneheaded statement stands.

And that's my point exactly.

And this is my quandary.

Clearly.

And that is the answer I was looking for.

Thank you, Dan!

[By the way, I see some NOS fuel pumps with the "screw-tops," which would likely be rebuildable – Have you had any experiences with those?
As much as I trust your initial recommendation, something I can take apart and fix makes me happier than something I can't.]

– Eric

When I needed a pump for mine I found a couple of NOS Carter ones on eBay and they worked fine. Not bad price either.one went on my /6, the other on my son's. And they both said "made in USA on them.

Yeah, I already bought an NORS AC pump this morning - $17 including tax and shipping ($10 less than the ChiCom crap I bought yesterday).

I may also buy a rebuildable Carter or AirTex, just to have, if I hear anything positive about them here.

My concern, of course, other than that the pump, you know, actually functions, is that the rubber can withstand modern fuel additives. I always use ethanol-free gas, but that's not to say that I might not find myself somewhere it's not available, or they may stop selling it near me.
The AC sounds good in this regard, and I saw one at a good price, so I didn't delay.

It's just annoying, because something that could have been fixed with a quick trip to any auto parts store and an hour of leaning over the fender cursing (in a parking lot, if necessary), is now a big complicated deal.

- Eric

I wish I could FIND ethanol free fuel. No such thing around here.
Oh yeah there is... The Tru-fuel all the box stores sell for my chain saw and weed eater at $7/quart ... And I ain't doing that.

Yeah, it's funny how spotty EtOH-free gas is.

Around here we've got a "regional" gas station chain that always has it, at 91 octane, as their top-grade fuel.
It's about a buck a gallon more than regular 87, but every one of their several hundred stations has it at every pump.

Yet, go into NJ, and you're SOL.

- Eric

You also said:
This is what led me to believe you were installing something other than a mechanical stock fuel pump I am not aware of the stock mechanical pumps ever have a pressure specification. My understanding is also that slant six carburetors function best with 7-7.5 pounds of fuel pressure.

With you having clarified that you are installing mechanical pumps, I agree completely agree with Dan. New parts are largely junk. Find a junkyard part or a NOS part. If you get lucky you can find one of the rebuildable pumps that were available in the 1960s.

Careful, Doc. "I've only seen X, so therefore there's nothing else" is a close relative of "I've never seen it, therefore it doesn't exist". Both are faulty.
Fun story, but no.
The OE '60-'63 fuel pump was a Carter M2996s bolt-together type which, yes, can be rebuilt. It's easy and they work well and last a long time. Kits can be bought without difficulty from one particular source, though you have to insist on a diaphragm spring of the correct strength, and double-check—the kits have been known to arrive with an 8-pound spring, which makes problems for engine operation (and for your universality-of-four-pounds idea).

But that specific pump is difficult to find any more. Not impossible, but you have to pay money and/or watch and wait.

Most of the bolt-together pumps that go across eBay are aftermarket items for which kits are a maybe-or-not deal. I avoid them. The giveaway is in the construction details. On the Carter pump there are no externally-visible screws holding the air dome (uppermost casting) to the valve body; often there is one or more such screws on the aftermarket pumps. And the Carters have a stamped steel arm, while the aftermarkets usually have an arm made of laminated steel plates, sometimes with a small stamping over the surface that rides on the camshaft.
Yup, it is annoying. It is the reality of having a 60-year-old car.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

[sigh.]

Okay. After a very cursory review of contemporary fuel pump pressure specs, it looks as though the fours and sixes (Jeep, Rambler, Dart) were spec'd at around 4psi, while the eights (Ford, Chevy, Olds) were spec'd at around 5-6psi.

So, you are correct, and I am wrong, by the letter (or number), but my general point, that 8psi is, as Brother Maynard would say, "right out," remains valid.

I shall revise my recollection of normal fuel pump pressures accordingly, and retroactively.

I'm sorry. I'll push back on this one. The same carburetors are used on many older cars with gravity-feed fuel, and later vehicles with fuel pumps (for instance, my 1959 Case bulldozer uses the same carburetor as a Model A Ford).
The low pressures of most fuel pumps on carbureted engines are not dissimilar to the pressures encountered in gravity-fed systems, and carburetors were not necessarily changed when the switch was made to fuel pumps in the 1930s (considering that V8s often required carburetors on top, usually downdraft, instead of updraft carburetors that could be placed on the sides of inline engines).

Do you know of other specific reasons why these pressures were chosen that would exclude gravity / pump interoperability as an explanation?

Excellent. I see exactly what you mean.

I will not go out of my way to buy one of those, but I will keep my eyes open and will pick one up should I encounter one.
Those are just what I would be looking for in an ideal world (but not at my ideal price).
For now, I await my NORS AC pump, for $16 shipped.

Sadly, the PO who installed the Chinese pump that failed threw out the original Carter pump (as far as I know... maybe I should e-mail him).

Thank you for all that information. With any luck, I may be able to get the car running, and take it out once more before the salt is on the roads, with its new door weatherstripping, which just arrived today.
I'm curious how it sounds at 70mph without the Devil himself blowing into my left ear.

- Eric

Take another look at the second pic I posted.
Go ahead—when you have examples relevant to the Slant-6 or its contemporaries.
Wouldn't do you any good; your car is a '64, so it was built with a crimped-together, non-rebuildable pump.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

'68 426 Hemi 8.5psi and HiPo 440 7.5psi. Outliers.

Slow evolution from a clear common origin. Pressures creep up from the initial ~3psi over several decades.
Ford Flathead V8 from the early thirties through the early fifties: 3.5 - 4.5psi.
Packard Straight-8 1950: 3.5 - 5.5psi.
You get pressures coming up another psi or two with "new technology" 1960s engines, as deigns diverge from their origins.

Ah. Thank you. That explains the "1960 - '63" application on all of them.

I'll sleep better now... If I can sleep at all tonight, of all nights.

– Eric

So. Dan.

Are there some fuel pumps that have a 1/2-20 thread for 5/16" tubing, and others that have a 3/8-24 thread?

Because the eBay "New" (with glued-on gasket and almost-imperceptible lever wear) AC 6972 pump in a 1970-marked box, with an included receipt from 1975 and a base stamping of 270K6972 has a 5/16" hose barb inlet and a 3/8-24 outlet.

Made it hard to screw in the 1/2-20 flare nut on my original steel fuel line.

Auto parts stores these days are next to useless. I had to buy a 3/8-24 to 7/16-24 adapter and a 7/16-24 to 1/2-20 adapter, because they don't apparently stock 3/8-24 to 1/2-20 (3/8 to 9/16, sure, no problem).
And yes, I did try the 7/16" in the pump, and it would not thread in, no matter what.

BUT pressure was 5psi, as it's supposed to be, fuel didn't pour out of the carburetor, none of the adapters leaked, and the car runs fine, including full throttle at 60mph.

That being said, I'm slightly concerned because the actual passage in the 3/8" adapter looks to be less than 1/8".
Is that okay?
Why would this pump, which is clearly the correct number, have the "wrong" outlet thread?

Any ideas?

Thanks,

– Eric

ps [edit]: Looks like I got a deal, too! The receipt from 12/8/1975, from Emmaus Auto Parts, to Ken's Arco in Allentown, shows a (presumably wholesale) price of $12.45, which would be $71.74 in today's dollars, and I paid $10, plus $6 shipping.
Woo Hoo!