RE: Fluctuating fuel pressure

[Rich Kinsley <rlkinsley@xxxxxxxxx>]

Currently I am in the mode of try and see how it works. It hasn't 
faltered or quit even when the pressure gauge said 2.5psi. It is not 
engine rpm actuated so I can't imagine it would go up because the engine 
was running faster. I would like to have an interior gauge to monitor it 
and a second gauge before the regulator.

Damn the torpedoes! Full speed ahead :-)

Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies
=====================================================================
sky62 wrote:
> 
> hey Rich, here is something from my Don D. folder-
> 
> Pascals law fo Fluid Dynamics states that pressure is distributed  
> with equal force in all directions.( We teach this when teaching  
> brake systems )As long as the supply of fuel to the pump is  
> sufficient (more than can be used ). As fluid or fuel is used pessure  
> will fall (at high RPM) It should not fall be low 5 ideally.
> I would go ahead and run it. If it is not enough you will know the  
> first time you wack the throttle
> Don
> Author of
> Return to Deutschland (True Adventure)
> Old Reliable (Mopar)
> 
> One of the big problems facing us to say when using mach fuel pumps  
> is that we are pulling fuel from the tank.
> When we reduce the presure in a liquid we also reduce its boiling  
> point or point when it convetrs from a liquid state to a gas state.
> It used to be  fuel manufacturers added  chemicals to reduce the  
> tendancy of fuel to boil and cause what we commonly called vapour  
> lock.  Now because all cars currnetly in production have fuel  
> injection with a line running full pressure from the tank to the  
> injectors there is no longer any reason to worry about vapour lock  
> conditions. However for us  with older cars with conventional fuel  
> pumps which pull fuel at low pressure from the tank to the pump and  
> are engine mounted (so they absorb heat from the engine,) it can be a  
> real problem. Enough of a problem in some cases the engine will  
> mysteriously quite after several successive stop lights in hot  
> traffic or suspicious no start conditions after a hot soak (sitting  
> hot shut off while you go inot a store for a loaf of bread for  
> instance. When you go to restat it doesnt want to start. Because it  
> is mysterious often the ignition gets the blame . In fact it is the  
> fuel pump absorbing heat. Gasolines with ethonal are even worse for  
> this condition. One cure that works well on BB mopars is to build a  
> very thin shiiled of aluminum and mount it on the fuel pump attaching  
> bolts so it shields the fuel pump from the front of the engine block  
> which it almost touches at the side or business end of the pump. This  
> will usually cure the problem on most cars and on some that are real  
> severe at least bring it to almost never status.
> The other solution that Bob aluded to is to install an electric pump.  
> The only problem is if you install a garden variety pump it may not  
> be able to keep up and if shut off just makes the regular pump work  
> harder severly limiting it violume. A good electric pump that will  
> handle everything by itself is often very noisy  which is something  
> that is not a lot of fun in a street car.  I think there are some new  
> brands of pumps that are not so noisy out there now but I havent  
> tried them. I did find a mech pump recently that has its business  
> ends lower and farther away from the block. I am getting ready to try  
> it out to see if it is a reasonable solution.
> Don
> Author of
> Return to Deutschland (True Adventure)
> Old Reliable (Mopar)
> 
> maybe some of this will help?
> 
> Schuyler 62 Dodge Dart 440 wagon w/ Poly 318
>   <http://www.1962to1965mopar.ornocar.org/ml-wrobel62.html>
> FYI - I Do the Decal designs for the Poly head 318 and more! email me  
> with your needs -
>   <sky62@xxxxxxxxxxxxx>
> 
> 
> 
> On Aug 3, 2009, at 11:58 AM, Rich Kinsley wrote:
> 
> >
> >
> >
> > Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies
> >
> > Things seem to be getting worked out nicely but I do see a puzzling
> > phenomenun. I set the pressure regulator to 6psi, let it run till it
> > warms up and it drops maybe down to 4psi. I swapped the press  
> > regulator
> > and it did the same thing. I guess I should get another fuel pressure
> > gauge and install it before the regulator to see if the pump output is
> > consistent.
> >
> > Anybody see a similar thing happen? It actually dropped to 2.5psi once
> > when it got real warmed up. It hasn't affected the performance though.
> >
> >
> > ----
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> >
> > '62 to '65 Mopar Clubhouse Discussion Guidelines:
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> >
> 



Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies


----
Please address private mail -- mail of interest to only one person -- directly to that person.  I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic.  Thanks!

'62 to '65 Mopar Clubhouse Discussion Guidelines:
http://www.1962to1965mopar.ornocar.org/mletiq.html.