what would happen if you took the return out of the ve....

[Don Tanklage]

... . and removed the orfice (or drilled it out) and replaced it with a rising rate regulator?



would it blow the pump up or what?



lol



just curious



don

 

[JAyers]

As long as you run a regulator, it would be fine. Im planing a regulated fass fuel system and Im going to run two feed lines into the ve, one in the regular inlet and one in the return. Im going to take a compression fitting and put it on the injector return line and run it to the regulator return. I know one person who is doing this and hes laid down some serious numbers

 

[Don Tanklage]

huh?



sounds like everything is goin in and nothin is goin back to the tank...

 

[Greenleaf]

I may be wrong, however in MHO, you just wercked your pump.

 

[cerberusiam]

As long as you run a regulator, it would be fine. Im planing a regulated fass fuel system and Im going to run two feed lines into the ve, one in the regular inlet and one in the return. Im going to take a compression fitting and put it on the injector return line and run it to the regulator return. I know one person who is doing this and hes laid down some serious numbers

If I understand what your saying your using the return line as a feed exposed to the same pressure as the inlet???



If so, bad idea. It may make big numbers but not for very long. That will block the cooling and lube flow to the pump.

 

[Don Tanklage]

... return line as a feed exposed to the same pressure as the inlet???



That will block the cooling and lube flow to the pump.

i wouldnt worry about lube - that pump is gonna have more fuel than it knows what to do with! (and no where to go). dont you think that will blow the seals in the pump????

 

[dpuckett]

I had considered that, too, when looking for a return line. But, when you let more fuel come into the return side, you also heat up the fuel that is in the pump (because the return fuel is hotter than the in-tank fuel). So, it is my hypothesis that the majority of the fuel is returned to the tank to help cool it off. Otherwise, it wont matter how much lube you have, you will burn stuff up.



Daniel

 

[Don Tanklage]

i dont know...



the pumps are pretty warm. i took my temp gun to different parts of the pump with the water at 180. temps varied but that pump is very warm. and the stock system runs the fuel thru a heater and the filter is on the head so i dont know that fuel heat would be a problem as far as longivity? regardless, there would be no reason to run a inlet to the return side. if you wanted it to see inlet pressure you could just install a rising rate reg there, and still return the fuel to the tank



that is what i was wondering - what happens as you build pressure on the return side???

 

[NIsaacs]

Per my "91" Cummins repair/troubleshooting manual, fuel return line pressure should not exceed [in Hg], [20. 4]



It also says this is important when using the Lucas CAV fuel pumps, however on the Bosch VE, Bosch P7100 and Nippondenso EP-9 fuel pumps it doesn't really say how important.





"NICK"

 

[JAyers]

The truck in question has ran this way for almost 4years 40,000mi and no problems yet. The fuel is regulated to 15psi. The pump only uses what it needs and the rest is regulated back to the tank. At idle it stays at 15psi and the fuel pressure rises 1:1 with boost. He has it limited to 30psi right now but has seen upwards of 40-50psi at full tilt with the dual feed setup. The only thing you have to worry about is the front seal in the timing case but we are workin on a way to solve that. His has loctite holding it in right now. He also runs a fuel cooler on the return side. But like I said no problems yet, he pretty much beats the crap out of it also.

 

[dpuckett]

Don, the fuel heater, as I understand it, is only activated in cold weather, kind of like the KSB.



JAyers- so he took the return to the pump completely off? If so, that is different from what I was talking about with full flow of the return fuel to the pump. The banjo restricts the flow quite a bit, and thus routes the rest of the fuel to the tank. I dont really see how having ALL the fuel go to the tank would hurt anything. cerberusiam? Greenleaf?



DP

 

[JAyers]

Yes the return was removed and a second feed line was added in its place, the two feed lines are coming from a aeromotive regulator which is set at 15psi.

 

[Don Tanklage]

Don, the fuel heater, as I understand it, is only activated in cold weather, kind of like the KSB.





DP

i hope not...



that is where i get the power to run the fass pump on my truck!



lol



(it actually just closes the relay, but has to keep it closed (and does) or the fass would stop)



iow your heater is on all the time

 

[Don Tanklage]

Yes the return was removed and a second feed line was added in its place, the two feed lines are coming from a aeromotive regulator which is set at 15psi.

on my truck the return from the injectors ties in to the return from the ve and goes back to tank



i still dont see why he didnt just put a stand alone regulator on the ve return to build pressure in there?



cant you drill n tap a couple of holes next to the front seal and install a couple of small button head allens to hold the seal in? (is there room?)



don

 

[Don Tanklage]

ps - was this guys pump (stomp, i am thinkin... ) fully rebuilt before he put 30 psi to it and 40k miles on it?

 

[Greenleaf]

If this is the cutting edge of technology for increased VE pump HP, he may not have wanted you to release the info.



I don't believe I will attempt this.



However, there is a VE overflow valve,but I don't have the part number.



Scott

 

[Don Tanklage]

i dont think it is big deal gl



i took mine apart today



the orfice is like . 018 so if you think it is gonna flow enough to drop pump temps i believe you are mistaken



with the orfice that small do you think 30 psi at that port could be too much of an issue?



plumbed the way josh suggested fuel can still get out of the return side, it would just have to be at above 30 psi to do it



i thought he was crazy, until i saw how small the hole was



don



ps - my afc tube was broke, probably was when i got the truck



the fuel pin was stock



the fuel screw was all the way out



it runs a little different now... .

 

[cerberusiam]

i wouldnt worry about lube - that pump is gonna have more fuel than it knows what to do with! (and no where to go). dont you think that will blow the seals in the pump????

The "no where to go" is the problem. If you do not return fuel somehow you are holding hot fuel in the pump. As the fuel heats the lube also breaks down.



There has to be something here that is not being explained completely. The 4years and 40k means nothing if this pump is running at close to stock levels. Now, crank the pump 220-250 cc's so we can approach enough fuel for 500 HP and lets see how long it will hold together.



FYI, when you start pushing a lot of fuel for injection you have to up the return flow for cooling and lube also.

 

[Don Tanklage]

do you know how a multiple outlet regulator works?



the fuel can still get out



true, it goes back over towards the other inlet (or out the bypass?)



it would just have to be at a slightly higher pressure than what ever the regulator is seeing



how much do you open up the restriction (in thousandths of an inch please) for the return when you turn the pump up to 500 hp and install twins and all?



instead of opening up a 018 hole to a x hole what would be the problems of my original questioned method? (a stand alone regulator instead of a fixed orfice)

 

[Don Tanklage]

how much do you open up the restriction (in thousandths of an inch please) for the return when you turn the pump up to say 500 hp?

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