Fuel System: R2 Carter "Super Pump" with Golden Hawk's WW-6-121A carb-- fuel pressure too high?

[bsrosell]

Hi,
1957 Golden Hawk w/ original supercharger and Stromberg WW 6-121A carb.

got my carb back from Daytona and mounted it yesterday to try it out, after MY rebuild seemed to be a failure over Christmas; it had finally started, but very rough, needed the choke butterfly held open just to run for 10-15 seconds, all the while it was flooding out and weeping at the gaskets.
Well, they did a beautiful job on the carb, but I have renewed confidence in my carb-rebuilding skills; it still runs almost the same. (OK, it runs a little better, they ARE the pros :-) )

NOW, it starts right up THE FIRST TIME then quickly dies unless I manually hold the butterfly open a bit. Let the choke close (maybe 1/8" gap? plus I have the Service Bulletins hole in butterfly), and it stumbles and dies. (This is in 30F Minnesota; that choke SHOULD be almost closed; I'm only running for 10 seconds or so, because no radiator, and not done the break-in run yet).
Lower gasket was saturated and weeping also (though not so much tonight, maybe swelled a bit overnight?).
I called Daytona and talked to the guy who rebuilt it. When I mentioned I had rebuilt a Carter Super pump for an R2, he guessed there might be too much fuel pressure.

But Shop Manual says 6-7psi fuel pressure for the Golden Hawk. I tried to measure my R2 pump tonight, connected after the sediment bulb, but a modern gauge is worthless at that low range.

1) update edit: a friend said R2 Carter super pump pressure is 5-7psi….. so SHOULD be a swap….

2) if the R2 pump pressure is comparable to the 57 pump, any ideas? Obviously Daytona ran it and was fine,

3), the Daytona guy's input was IF pressure too high "have to play with float height.." and lower until I compensate; BUT, how would I ever know when I got it right? :-(

Appreciate your support, as always.
Bar

[jts359]

Anything more than 5 lbs is too much for that carb , You can buy good gauges from many places but you would have too make a inline tubing to adapt it , Also maybe during shipping or installation a piece of crap is caught in your needle and seat , Ed

[bezhawk]

Daytona needles and seats are flat disc type, not a tapered needle and seat. They can be overcome by fuel pressure more easily because they are larger. What you might try doing, is make the return line orifice larger...say .050 and see if that reduces the fuel pressure some. I think stock restriction is .045. If that doesn't do it go to .060.

[E. Davis]

Why not put a fuel pump regulator in the line so you can adjust it to where it runs best.

[PackardV8]

Don't most supercharged Studes run a pressure reference line from the carb to the fuel pump to hold 5 PSI as the carb housing pressure increases with boost?

jack vines

[GTHawk]

Why not put a fuel pump regulator in the line so you can adjust it to where it runs best.

Great idea this will tell you if it is a pressure problem. install on the input line. good luck.

[StudeRich]

All this is good info, except: the "Float Level" is NOT going to help with over-pressure, so the other suggestions WILL work.

The R1 Carter "Super Pump" is much more about More Volume than pressure.

I see you already do HAVE a '63/4 GT Hawk/Lark Fuel pressure modifier/Filter/Return System.
Might as well go all the way and finish the job!

I only see ONE problem, you MAY need to smash the Corner of your Left Engine Mount Bracket to clear the Larger Diaphragm and Housing size of the Super Pump.

[bsrosell]

thanks.
JTS359: I'm confused with "5 psi is all this carb can handle" when factory specs for the Golden Hawk's fuel pump were deliberately increased to 6-7psi. Technically "identical" pressure to the R2 Carter Super Pump . And I may call Daytona back and ask about the needle/seat; if swapping just that back to a needle would help, should work as original (IS "all original" for carb, and input pressure?).

Jack, yes, there is a line from the S/C to the fuel pump. BUT I"M NOT RUNNING THE S/C YET! Could that correct the problem when I put the belt on S/C, put the air-box on, and that comes into play?
But if so, it seems any of you with supercharged Studes would have the same problem; running very rich until the box is on and S/C connected? I don't remember how that system is designed to work.....

re: Bez's input, if I open up that return orifice on top of the sediment bulb (yes, 0.45"), is that truly for pressure regulation, or simply to allow a return-flow to the tank? Anyone know? I'd be afraid of opening it up and reducing fuel-pressure too much, if it is designed to be a pressure-reducer?

Rich,
1) Indeed! I had to replace my original crossmember with a 61 or 62 Hawk's.. and got the original blueprint from Andy that showed where and how deep to pound that "dimple" for clearance for the ORIGINAL pump. And then mounting this one, found I had to heat and pound it another 1/4". The guy on assembly line who did that job had good muscles!

2) yes, that plumbing (enabling a return line, and original Stude fuel filter I can SEE) is primarily why I went with this fuel pump. My part supplier/friend also recommended the R2 pump because of the extra volume, and happened to have a good core for me to rebuild, along with the sediment bulb.

Can you please explain what you mean by "might as well go all the way......"? These comments reminded me of the interaction/design of the pressurized line from the S/C to the pump, AND that relief orifice in the sediment bulb/filter housing. It seems it should work "as is", and Stude already designed in "fuel pressure regulation" for super-charged engines...
So, I'm reluctant to add a regulator until I really know it needs that......
I know I'm missing something, appreciate all the input and suggestions!!!

[Mike]

When you rebuilt the "R" pump, what spring did you use on the diaphragm stem? That's what determines max pressure. Original "R" is pretty light. R1 & R2 internals are the same. It's reinforced by the pressure from the supercharger via the boost reference line, on an R2. The spring in the "Then & Now" kits is much lighter. A diaphragm assembly from a Ford "X" pump is heavier.
I see from your picture, the pump has an R1 style vent. I assume you plugged it internally when you drilled for the boost reference. It's easy to tap for a set screw inside. By the way, Golden Hawks had a 3/16" boost Reference line, R2's went to 1/4".
The size of the orifice in the carb inlet valve presents a dilemma. A larger orifice will flow more fuel, but, since more of the needle is exposed to pressure, it floods easier.
Although the engineers intended the return line to cool the fuel to the carb, I think the most useful thing it does is allow pressure to bleed off when the engine is shut down. Otherwise, as fuel evaporated, or even boiled off, in a hot carb, more would flood in from a pressurized fuel line, making hot restarts difficult.
A few years ago, I bought a very serviceable Vac/press gauge kit from Sears for less than $20. Later I found I could buy just the gauge as a repair part for even less. - All brass internals, made in China.
Mike

[StudeRich]

/Cut/Rich,
1) Indeed! I had to replace my original crossmember with a 61 or 62 Hawk's.. and got the original blueprint from Andy that showed where and how deep to pound that "dimple" for clearance for the ORIGINAL pump. And then mounting this one, found I had to heat and pound it another 1/4". The guy on assembly line who did that job had good muscles!

2) yes, that plumbing (enabling a return line, and original Stude fuel filter I can SEE) is primarily why I went with this fuel pump. My part supplier/friend also recommended the R1 pump because of the extra volume, and happened to have an NOS one for me to rebuild, along with the sediment bulb.

Can you please explain what you mean by "might as well go all the way......"? These comments reminded me of the interaction/design of the pressurized line from the S/C to the pump, AND that relief orifice in the sediment bulb/filter housing. It seems it should work "as is", and Stude already designed in "fuel pressure regulation" for super-charged engines...
So, I'm reluctant to add a regulator until I really know it needs that......
I know I'm missing something, appreciate all the input and suggestions!!!

I simply meant, if you have converted this GH from the Stock straight/standard Fuel Lines to the R1/R2 Setup, why not use a Real R2 Fuel Pump. No hidden or secret meanings there.

[bsrosell]

Mike, I've searched my records (and shop), and the mfg of the R2 pump rebuild I did not record. BUT, "Then&Now" sounds familiar, think it was from them. Have photo (attached) of kit but no name on the instructions. Doubt anyone recognizes from the kit? Seeing the (now-old) photo, I recall I did reuse the original mushrooms, instead of the brass rivets supplied (per a post here on rebuilding the R pumps)

Rich & Mike, re your comment about the R1 style inlet and being an R1 pump; I know Brent Hagan sold it to me as an R2 core. I did not drill anything, the port I've connected the boost reference line to is original and was threaded. I am pretty sure it also had the boss on the inside, so from photos elsewhere, I BELIEVE is an R2 and the port is intended for the boost ref line. Do you see something indicating otherwise?? (and since boost line connected and no "vent hole' elsewhere, would it matter?) I

I went out again tonight; Doofus recommended viewing the main jets at idle, and said there should be NO dripping there at idle. Well, there is, so appears I either have too much pressure (and likely due to something I messed up in rebuilding, since Then/Now spring would be less pressure if anything?), or that new Daytona float valve set up is overpowered and letting too much in. It DOES seem to run better each time I start it (only run it 15-20 sec, no radiator). Time for a new, lower range fuel pressure gauge so I know what I'm dealing with. When I do, will come back here and let you know.
THANKS everyone!
Barry

[Mike]

The kit doesn't look like the Then & Now kits I bought in the past. They didn't secure the spring in place and used a different upper seal. I like your style better, but you can't easily change the spring. You may very well have a heavier than stock spring, and higher pressure.
I have both R1 & R2 original pumps right here. R1 is stamped 3509S, R2 is 3508S. The only difference is which passages, that vent the back side of the diaphragm, are drilled. I see your pump has the R1 vent drilled through on top. I conclude it's an R1 pump modified for use with a supercharger. Both R pumps have the boss. R1's aren't drilled. Hopefully, who ever drilled the boss for the boost reference, also plugged the R1 vent.
Fuel pressure needs to be a few pounds more than supercharger pressure. The boost reference reenforces the spring on the stem so fuel pressure increases with supercharger pressure. If the R1 vent isn't plugged, fuel pressure won't track with supercharger pressure, and you'll starve for fuel under boost.
I think your flooding problem is probably a bit of dirt in the carb inlet valve. That inlet valve may not handle high fuel pump pressure well, since more surface area is exposed to pressure, and you may have a heavier than stock spring. I'd expect that to manifest itself as just a rough idle since the carb is flooding a little, but you are describing a gusher!
Did you run a 1/4" return line all the way to the tank? If it's restricted, other than the .04 orifice in the fuel filter, pressure will be high. Also, the fuel line from the tank to the pump should be 3/8".
Mike

[jpepper]

I have had a few R1 and R2 pumps that produced almost 10 PSI. Check your pump. You may need a regulator.

[bsrosell]

UPDATE: have waited to reply until I could get GOOD information.
1) Mike & Rich, I did confirm (finally found the casting number with mirror on BACKSIDE of pump) it is an R2 pump, 3508S. and no vent-hole. (stamping appears backwards of course because of the mirror)

2) re: Pressure: I bought a 0-10psi gauge and plumbed up in parallel with a "T" fitting so I could run more than a few seconds. Got just under 6psi BEFORE the fuel-filter/relief/return-line, and about 4.8psi AFTER the fuel-filter (what the carb sees). (hard to know for sure, with my finger in the choke to keep idling somewhat smooth and high enough to steady out needle)
(note for future readers: I first bought a 0-15psi gauge, and was not accurate that low, got only about 3psi...)

4) Mike, see photo; yes, have the 1/4" return line from (later) Stude fuel-filter w/ the 0.040"(?) bypass orifice, and have the correct 3/8" supply line all the way up to the fuel-pump. (the 1/4" line is connected to a step-up 5/16" fitting on a 56J sending unit, so no restriction there).

So, it appears I have proper operation/pressure of my R2 "super-pump"? And the reduction to ~5psi or less due to the fuel-filter pressure-relief orifice, is ok per other comments above?
(if 5psi is sufficient, why was the original Golden Hawk pump increased to "6-7psi" per the '57 Supplement? That seems curious to me if the WW-6-121 carbs shouldn't have more than 5psi...??).

regardless, doesn't seem my problem is high fuel pump pressure after all.

I wish I could attach video, then you can really see the gas dribbling out of the main jets at idle (photo here shows where I'm looking at least). and can see the gas sitting on top of the throttle butterflies. (and gasket starting to soak up with gas).
As refresher, engine does NOT start unless I open the butterfly about 1/4", and have to keep it there to prevent it dying off from flooding. (runs pretty smooth WHILE I do this).
Besides "running rich", gasket between throttle-body and carb saturates while running, apparently due to all that gas spattering out and around from the main jets and pooling on top of the nearly-closed throttle....?

Again, trouble-shooting with no radiator yet, only run for 20-30 sec at a time, so no time to play. Now that I know the fuel-pump is ok, I'll get that radiator on. Makes me nervous everytime I start it up without it.

So with correct fuel pressure, a "brand new" Daytona-rebuilt carb, just run and adjusted there obviously, and highly unlikely any crap could have gotten in the carb in simply re-connecting the few inches of tubing between fuel-filter and carb..... any ideas now?
(would I have the dribbling from main jets at idle, if the float-needle IS leaking? Dufus mentioned that in regards to a symptom of high fuel-pressure., which I don't have....)

Thanks!
(will start a new post referencing carb issues after responses to this thread, but wanted to finish this one off for anyone in the future looking at fuel-pump pressure problems).
Barry

[StudeRich]

OK, here is something you should know. The WW 2 Barrels have a Early '53-55 or '56 Base Gasket that has 2 Holes for the Throttles.

Non Studebaker people like "Daytona Carb. Experts" would not know the difference, since it goes on the appropriate CAR not Carb.
However your '57 should have the '57-'64 Kidney shaped ports Base Gasket; Part Number 1540006.

That might be a long shot, but COULD make a difference, I would check it.