12V mechanical FP

duke1n

duke1n

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Apr 24, 2006
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Getting ready to install 12v mech pump and notice the fittings are definitely smaller than 3/8" pipe. Intake looks smaller than 1/4" pipe. With fittings that small it seems like it would make for a significant restriction in the system?
 
I take issue with this. I gave you my opinion already LOL
 
You're a VP guy Timmy, what would you know about 12V FP lol

I figured with all the very knowledgeable 12v guys that one of them would have come on here and said you've got the wrong pump SpongeBob or those 12V pumps flow a buttload of fuel through brake line sized fittings so don't worry about it.

There will be no grammatical analysis for anyone answering this thread so no worries...
 
i rigged up a dual feed to my p pump. i have the stock line to the stock location. then i have another pump that kicks in at 20 lbs of boost and feeds the front gally of the pump.
 
This is for use on a VP truck so I'm not sure if it's a "heavily" fueled app. Just makes me pause for thought when I scrapped the crappy electric LPs that were all 3/8" and -8an fittings and now am going to have a 1/4" restriction at the pump intake. Guess I'll hook it up and see what happens...
 
No regulator here just hope it can keep up with the volume needed through that tiny little inlet.
 
Bad idea Dukey, get a RASP if you really want a mechanical pump or an aeromotive with bypass/return regulator for the electrical route.
 
THe VP44 won't like the pressures generated by the mechanical LP.

Have to go another route.

~Wes~
 
I appreciate the input guys... I'm being serious. That said, I know of a couple guys that have been running unregulated for thousands of miles. I know this goes against what some have said but what can ya say... I suppose you could run a bypass so you didn't build heat but then again the VP already has a bypass. My concern was the tiny 1/4" input, if the pump I had bought had was the right one since the old part# had been superceded, and if with that it would keep up with 600hp VP motor. Let me find those old threads from Don...

"The pump numbers that RUSS posted are the same pump we have used/supplied. It is a smaller version of the pump used on the 12 Valve Cummins, but it supplies more than enough fuel for the VP44. The difference is in the cam lobe that drives the pump. It is milder than a standard 12 V lobe to help control very high pressures that can be experienced with the mech pumps.

This was on purpose to help anyone that wanted to get the pump from Cummins could in an emergency or as a new install with the cam.

There has been some paranoia over the higher pressures still experienced with this system, but it is misplaced. You will never need to even think about the fuel pressure or volume again. You dont even need to run a gauge. It is that reliable."

""This is for a 24 V with the VP-44. 30 PSI is perfect for performance. We have another system as well, but the pressure is typically only 22 PSI at WOT and around 6 at idle. Most guys opt for the 30 PSI system. The only difference is the supply pump we supply.

The 30 PSI system is the best route, IMO. Back when the 12 V mechanical pump started being installed in the 24 V with the VP-44 pumps, people were seeing around 55 PSI on average. Even at idle it could be as high as 50. That was years ago and no reports of failures were reported from this pressure. Remember the internal feed/suction vane pump inside the VP44 is raising the pressure over this value to the plungers. Anything you can do to increase pressure to vane pump is a good thing. To a point of course.

Back when things were getting going hard we tested, on the dyno, many pressures that made the best HP for the 24 VP44 engines. 22 PSI and up was the best, with no more or less power made at 50 up to 72 PSI. At 72 and up we lost a few. Probably from cavitational losses."
 
i just checked my fuel pressure this morning and i had right at 40psi at idle and i WOT going down the road it would drop to about 15-20.

Does this sound correct??

Lance
 
Different animal than what I'm doing. Maybe one of the 12v guys can tell you...
 
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