Walbro and boost ref regulator

[oldestof11]

Seeing as its pulling through stock lines, I can only get 30psi according to the pressure gauge. I am sure if I upped the lines from the tank, it will have more.

Now, come spring, I will be mounting the pump under the truck near the tank and have 1/2" all the way through.

Also in spring, I hope the have the custom VE and my extra refreshed engine in.

Dar, another thing to remember, the VE has MAJOR inlet restrictions and flow will no help it, only pressure. So 30psi @ 70gph is better than 9psi @ 120gph. The VE unfortunately has little to help in flow fuel in and out. I hope to change that with the new pump. The new one will have increased inlet size (read: less restriction, more GPH) and increased return allowing for high RPM's and BIG H&R...

[ellis93]

How does this set up do for every day use. How long do they last is what I'm askin.

[unixcowboy]

Dar, another thing to remember, the VE has MAJOR inlet restrictions and flow will no help it, only pressure. So 30psi @ 70gph is better than 9psi @ 120gph. The VE unfortunately has little to help in flow fuel in and out. I hope to change that with the new pump. The new one will have increased inlet size (read: less restriction, more GPH) and increased return allowing for high RPM's and BIG H&R...

Correct me if I'm wrong but doesn't the VE DEPEND on return restriction to control internal timing ???

Seems to me that increasing the return size will throw off the timing in the VE.

[Ace]

Seems to me that increasing the return size will throw off the timing in the VE.

It's not the tubing in the return line, but a little restrictor with a coarse filter screen in the outlet that holds case pressure. Bigger return tubing is not needed. It's going to return fuel at a similar rate for any given fueling level, regardless. Actually more fuel would seem to imply less return, depending on the injector bypass rate. I see no reason to change the stock return lines and IIRC, KTA made a similar comment once awhile back.

[oldestof11]

Yes it will.

But with the KSB and a timing spacer, I believe it can be controlled. The big thing with the VE seizing is fuel gets hot really quick from what I read. So, more in and more out equals more cool fuel.

[IowaCummins]

well she holds 17psi all the way to 110mph and seemed like if it had my rpms she would go further! that was with the boost ref not hooked up. now its hooked up and pegs the needle of a 15psi mr gaskets gauge. so idk what she is really puttin out. but i need way more timing cause it runs like crap with out the ksb hotwire switch on. starts way easier and idles so mush better! i love this set up.
this upgrade added so much that the tranny will not hold the power. any thing over half throttle is just making heat and doing nothing. so tranny building begins sooner than i thought!

[Ace]

Yes it will.

But with the KSB and a timing spacer, I believe it can be controlled. The big thing with the VE seizing is fuel gets hot really quick from what I read. So, more in and more out equals more cool fuel.

Really? Please explain. You would have to know if and how the injector size affected their return flow rate to know how much if any additional fuel is being bypassed. The VE oulet orifice is a fixed restrictor, so the flow rate will not change much, regardless - slight increase or decrease tracking with case pressure, that's all.

The reason they may get hot is because there's not enough fuel coming in, not because of anything to with the return path (unless it is blocked). Input is directly proportional to output: Input minus amount burned = output. Never changes. Overall flow seen into the return line is based on the injector variable which I don't know, nothing to do with the VE. If the return line was too small they would overheat all the time. If it's too big it won't make any difference in the flow/cooling rate on a given system.

There is a simple test you could do to see if your return line is too small. Disconnect it at the tank, put it in a 5gal can and run it up to speed. If it appears to be flowing under high pressure, spraying violently, it may be too small. If you do decide to upgrade it, you should probably run the new line(s) all the way up to the injector return, because that is where the extra flow will be coming from.

[oldestof11]

Thanks Ace.

I am only going by what I read and what others tell me. So that does make me a keyboard racer. However, I was planning on doing something like you said with testing the return. I also plan on getting the case pressure readings before and after modifications. I currently have 2 6bt's and 3 VE pumps. So, I can do a lot of testing.

Another thought is completely doing away with the return orifice and putting an adjustable flow control of some sort on it to keep the pressure constant and adjustable for any application.

You really don't need high flow when you are driving around, occasional romp on the go pedal, towing. But drag racing, dyno's, sled pulls all require high RPM's and the 14mm H&R for whatever reason, seizes when meeting with high RPM's...

Just my thoughts on it...

[PRINCETON_JAKE]

I cant believe no one said anything about the pump location yet. You should have it mouned as close to the tank as possible, pumps are designed to push fuel not suck fuel.

[Ace]

...pumps are designed to push fuel not suck fuel.

Would that explain why every fuel pump ever installed by the factory on a Cummins-equipped Dodge up until about 2006 was mounted to the engine?

[JBradley500]

All electric pumps push fuel better than they pull fuel.

[Ace]

All electric pumps push fuel better than they pull fuel.

Yup, for the most part in the automotive world that is - and that's why it's only makin' 30psi.

Which in this case is a good thing.

But there are electrics designed to go either way like Walbro FRB's, Carters used in the 24v's and early commonrails, and alot of other marine variants made by many manufacurers. Regulations in most countries require them to be mounted a certain distance away from the tank. I'm sure Ritchie can chime in on that.

"All"(ways) and "never" are rarely gonna be entirely accurate terms.

[BC847]

I think one of the primary reasons for mounting the pump in the tank is to reduce the chances of vapor-lock . . . in a gasser application. Don't know for sure if diesel is as prone to such.

[Ace]

...reasons for mounting the pump in the tank is to reduce the chances of vapor-lock . . .

That's what they say, but I never understood why. I suppose the pump itself may add a tiny bit more heat to the fuel just by pumping it, but I cannot imagine how it would be enough to make much difference in any propensity towards vapor lock, regardless of where it's mounted. As far as an electric pump in the tank goes (gasser or diesel) the pump itself being cooled by the fuel should greatly improve reliability. Electric motors do tend to get hot.