Engine/Transmission (1998.5 - 2002) Holly Blue not the Answer: For Me(VERY LONG)

[Gary - K7GLD]

I think the way to help prevent cavitation is to setup a fuel bypass back to the tank so fuel is flowing all the time.



I think the vane type pumps are not particularly well suited for the kind of application we have that pump against a set pressure. That is why the gearator or the parallel gear pumps work so well. Those pumps work well against a restriction that develops the pressure for the VP44.



Anyone know what the real in place Walbro 392 does in gph when working against a VP set pressure of about 14 psi? Not the theoretical graph lines, the actual in place install.



Bob Weis

HMMMmmm - my spare/backup Walbro is still in the box out in my garage - if I get time and decent weather, I'll hook up a test bench and run a few flow tests at varying PSI... Probably also check amperage draw at the same time...

 

[Gary - K7GLD]

As a followup to Bob's earlier question, here's what I dd - this is also in another separate thread:



Bob Weis is considering use of a Walbro GSL-392 fuel pump, and asked as to "real world" flow rate at a nominal 14 PSI, as some use as a target PSI with the required bypass regulator.



Since I have a spare 392 waiting installation, I decided to fabricate another working complete system, including the automatic flow bypass I use on all my own installations, and a regulator/bypass that returns unused, excess fuel PSI back to the fuel tank. I got all that assembled, then set it up on a test bench for a "live" test:



#ad




The operating PSI looked like this:



#ad




Right on target!



Set up as above, the fuel flow worked out to 1 gallon in exactly 45 seconds - 80 GPH, and the amp draw was measured at slightly over 6 amps. Here's the Walbro flow/PSI/amp chart for the 392:



#ad




All the above was interesting to me - I had assumed current draw was in the 5-7 amp range, which is well within the 20 amp contact rating of the control relay I use in my setup - glad to see my assumption was right!