Fuel System: 57 GH Fuel Pressure Question

[kirkdob]

My Golden has the Stromberg WW 2 barrel carb and runs a fixed pulley Paxton supercharger. I have completed my fuel system upgrade as follows:
Removed mechanical fuel pump, installed Holley Blue electric with adjustable Aeromotive return style pressure regulator. Plumbed 3/8" return line to tank. Regulator as near carb as possible to keep cool fuel circulating to help eliminate vapor lock. Regulator is boost sensitive and is regulated by hose nipple on blower outlet similar to stock mechanical pump.

My question: I have the regulator adjusted to about 3psi at idle. As RPM increases the boost coming out of the supercharger nozzle signals the regulator to increase the pressure. At freeway speeds it runs about 6psi, a little more if I'm going over 70-75 mph. I don't want excess pressure overpowering the float needle and cause fuel to overflow. I still have the brass float needle, thinking of switching to rubber (Viton) tipped needle.

Does anyone know what pressure the WW can safely handle? Supercharged motors need variable pressure. I just don't know what is acceptable.
I've had so many different answers and theories thrown at me I was hoping someone hear has the answer.

Thanks!

Kirk

[RadioRoy]

Won't the effective fuel pressure on the float needle be reduced by the amount of the atmospheric boost pressure?

Isn't the carb enclosed in the boost chamber on a 58?

[kirkdob]

Won't the effective fuel pressure on the float needle be reduced by the amount of the atmospheric boost pressure?

Isn't the carb enclosed in the boost chamber on a 58?

Yes, but with fixed pulley, there is boost signal at steady speeds. I don't need to floor it to increase pressure. Runs 6psi at freeway speed even at light cruise, say 10-15 hg manifold vacuum. I don't need manifold gauge going to boost to see increased fuel pressure.

[BobPalma]

Kirk, I don't know why you are posing the questions: It honestly sounds like everything you've done is just right if you ask me. If it's running good as you've set it up, it should be doing fine. BP

[kirkdob]

Bob
I am happy with results. Just don't want to overpower float needle and send gas on a hot motor at freeway speeds. So you think 6 psi is safe for freeway cruise pressure?

[BobPalma]

Bob
I am happy with results. Just don't want to overpower float needle and send gas on a hot motor at freeway speeds. So you think 6 psi is safe for freeway cruise pressure?

Yes; it should be fine. I wouldn't want any more pressure, so you could be prepared to lower it just a tad if you smell gas.

But I don't think I'd touch anything if it runs well. It sounds well sorted-out as is. BP

[Studebaker1962]

Since I saw BobPalma's Latin tag line I had to throw in this theory of problem solving. Turn one screw at a time, observe the outcome and go for simple first.

Jim



What is Occam's Razor?

Occam's (or Ockham's) razor is a principle attributed to the 14th century logician and Franciscan friar William of Ockham. Ockham was the village in the English county of Surrey where he was born.
The principle states that "Entities should not be multiplied unnecessarily." Sometimes it is quoted in one of its original Latin forms to give it an air of authenticity:
"Pluralitas non est ponenda sine neccesitate"
"Frustra fit per plura quod potest fieri per pauciora"
"Entia non sunt multiplicanda praeter necessitatem"
In fact, only the first two of these forms appear in his surviving works and the third was written by a later scholar. William used the principle to justify many conclusions, including the statement that "God's existence cannot be deduced by reason alone." That one didn't make him very popular with the Pope.
Many scientists have adopted or reinvented Occam's Razor, as in Leibniz's "identity of observables" and Isaac Newton stated the rule: "We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances."
The most useful statement of the principle for scientists is
"when you have two competing theories that make exactly the same predictions, the simpler one is the better."

The principle has also been used to justify uncertainty in quantum mechanics. Heisenberg deduced his uncertainty principle from the quantum nature of light and the effect of measurement.
Stephen Hawking writes in A Brief History of Time:
"We could still imagine that there is a set of laws that determines events completely for some supernatural being, who could observe the present state of the universe without disturbing it. However, such models of the universe are not of much interest to us mortals. It seems better to employ the principle known as Occam's razor and cut out all the features of the theory that cannot be observed."
But uncertainty and the non-existence of the ether cannot be deduced from Occam's Razor alone. It can separate two theories that make the same predictions, but does not rule out other theories that might make a different prediction. Empirical evidence is also required, and Occam himself argued for empiricism, not against it.
Ernst Mach advocated a version of Occam's razor which he called the Principle of Economy, stating that "Scientists must use the simplest means of arriving at their results and exclude everything not perceived by the senses." Taken to its logical conclusion, this philosophy becomes positivism; the belief that there is no difference between something that exists but is not observable and something that doesn't exist at all. Mach influenced Einstein when he argued that space and time are not absolute but he also applied positivism to molecules. Mach and his followers claimed that molecules were metaphysical because they were too small to detect directly. This was despite the success the molecular theory had in explaining chemical reactions and thermodynamics. It is ironic that while applying the principle of economy to throw out the concept of the ether and an absolute rest frame, Einstein published almost simultaneously a paper on brownian motion which confirmed the reality of molecules and thus dealt a blow against the use of positivism. The moral of this story is that Occam's razor should not be wielded blindly. As Einstein put it in his Autobiographical notes:

"This is an interesting example of the fact that even scholars of audacious spirit and fine instinct can be obstructed in the interpretation of facts by philosophical prejudices."
Occam's razor is often cited in stronger forms than Occam intended, as in the following statements. . .
"If you have two theories that both explain the observed facts, then you should use the simplest until more evidence comes along"
"The simplest explanation for some phenomenon is more likely to be accurate than more complicated explanations."
"If you have two equally likely solutions to a problem, choose the simplest."
"The explanation requiring the fewest assumptions is most likely to be correct."
. . .or in the only form that takes its own advice. . .
"Keep things simple!"
Notice how the principle has strengthened in these forms which should be more correctly called the law of parsimony, or the rule of simplicity. To begin with, we used Occam's razor to separate theories that would predict the same result for all experiments. Now we are trying to choose between theories that make different predictions. This is not what Occam intended. Should we not test those predictions instead? Obviously we should eventually, but suppose we are at an early stage and are not yet ready to do the experiments. We are just looking for guidance in developing a theory.
This principle goes back at least as far as Aristotle, who wrote "Nature operates in the shortest way possible." Aristotle went too far in believing that experiment and observation were unnecessary. The principle of simplicity works as a heuristic rule of thumb, but some people quote it as if it were an axiom of physics, which it is not. It can work well in philosophy or particle physics, but less often so in cosmology or psychology, where things usually turn out to be more complicated than you ever expected. Perhaps a quote from Shakespeare would be more appropriate than Occam's razor: "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.".
Simplicity is subjective and the universe does not always have the same ideas about simplicity as we do. Successful theorists often speak of symmetry and beauty as well as simplicity. In 1939 Paul Dirac wrote "The research worker, in his effort to express the fundamental laws of Nature in mathematical form, should strive mainly for mathematical beauty. It often happens that the requirements of simplicity and beauty are the same, but where they clash the latter must take precedence."
The law of parsimony is no substitute for insight, logic and the scientific method. It should never be relied upon to make or defend a conclusion. As arbiters of correctness, only logical consistency and empirical evidence are absolute. Dirac was very successful with his method. He constructed the relativistic field equation for the electron and used it to predict the positron. But he was not suggesting that physics should be based on mathematical beauty alone. He fully appreciated the need for experimental verification.
The final word is of unknown origin, although it's often attributed to Einstein, himself a master of the quotable one liner:
"Everything should be made as simple as possible, but not simpler."
The pithiness of this quote disguises the fact that no one knows whether Einstein actually said it (this version comes from the Reader's Digest, 1977 [US: July, UK: October?). It may well be a precis of the last few pages of his "The Meaning of Relativity" (5th edition), in which he writes of his unified field theory: "In my opinion the theory here is the logically simplest relativistic field theory that is at all possible. But this does not mean that Nature might not obey a more complex theory. More complex theories have frequently been proposed. . . In my view, such more complicated systems and their combinations should be considered only if there exist physical-empirical reasons to do so."
References:

• W. M. Thorburn, "Occam's razor", MindMindA Brief History of Time.
  Albert Einstein, Autobiographical notes
  Isaac Newton, Principia: The System of the World

[BobPalma]

Goodness, Jim; that's some heavy thinking, there!

It reminds me of one exercise / experiment done long ago by our legendary Studebaker Drag Racer, Ted Harbit.



Obviously, when Ted was campaigning The Chicken Hawk as a stocker back in the 1960s, he was pretty much on his own as to experimenting to see what would work, and what wouldn't, to make it go faster.

As a stocker, he could run headers and open exhaust, per the rules. Any length exhaust pipes, or none at all, aft of the collector pipes, was permissable.

Ted told me that he once ran long pipes under the car from the header collectors, almost to in front of the rear axle. Then he ran the car on his personal "drag strip" he had marked off on the county road near his Dad's farm in NE central Indiana, where he worked on it.

He recorded the car's ET with the exhaust pipes at a certain length.

Then, he went home and cut off the exhaust pipes in increments, again running the car and noting the ETs, until he was satisfied that he had reached the optimal exhaust pipe length for proper scavenging that produced the best ET.

Pretty cool, I thought, and part of the determined methodology with which he was able to score EIGHT National Drags Class wins in ELEVEN years from 1962 through 1972, and runner-up in two of the three yerars he was not National Champion.

('Hope you don't mind this diversion in your thread, Kirk...you know there's always something around here...) BP

[Studebaker1962]

Yes, It's my fault to hijack the thread. Point being, as an Engineer, I tend to over complicate the solution. Thought I would share this theory. It is very good for us over thinkers. I am fighting a stalling problem on my 62 GT Hawk, it might just be the choke isn't opening fully. KISS: Keep It Simple Stupid

Back to You Kirk

Sorry,
Jim

[kirkdob]

No worries. To own a Studebaker requires intellectual superiority, a quick wit and duct tape. Since I am in possession of only the 3rd item I welcome all exposures to brilliance.

[kirkdob]

No worries. To own a Studebaker requires intellectual superiority, a quick wit and duct tape. Since I am in possession of only the 3rd item I welcome all exposures to brilliance.

Correction, wife "borrowed" duct tape. Comment on having 3rd item now rescinded.

[kirkdob]

I found this online today http://vs57.y-block.info/fuelpump.htm

Very good details, options and charts of how to arrive at the proper fuel pressure under boost. Anyone running supercharger should print a copy. Boost pressure/fuel pressure correlation charts are near the end of the document.

[StudeRich]

That IS a good read but there certainly is a whole lot of Ford applicable data, instructions, and procedures that cannot be crossed over to Studebaker.

Since Studebaker never used a Intake Manifold or Carb. Vacuum equalizer system like that Ford setup, many of those specs in the chart may not be correct? Maybe someone who actually understands it, can explain.

[kirkdob]

Hi rich,

The Ford idea was quite elaborate. While we would not try to duplicate that system it shows we aren't the only ones with issues regarding fuel pressure on supercharged cars. It was interesting to see fuel pressure control attempts and stats both successful and unsuccessful in trying to deal with the problems.

I found the write up on electric pump only and return style regulator to be exactly what I did on mine except for parts brands. I also added a 3/8" return line to the tank.
Seeing that system in print along with the boost pressure/fuel pressure chart led me to order one more gauge for under dash. Right now I have a fuel pressure gauge mounted inside so I can monitor pressure under varying driving conditions. Now I will add a boost pressure gauge next to it so I can adjust my fuel pressure to run about 2 psi higher than boost pressure. With the return style regulator I also expect vapor lock to be gone forever with cool fuel in constant circulation.

[kirkdob]

Final chapter. I installed one more gauge just to be sure everything is as it should be. I mounted a boost pressure gauge under the dash. It attached a T to the boost line from the supercharger to the fuel pressure regulator. It sits next to the fuel pressure gauge. Now, while driving as rpm increases I can see boost pressure rise and the corresponding increase in fuel pressure. I have fuel pressure set to run about 2-3 lbs above boost pressure. Only thing I might change in the fuel pump. Holley blue works well, but is noisy as hell. I understand Edelbrock has a similar pump that is much quieter.