justinp20012500

Quoted from TDR...

http://turbodieselregistry.com/forum...27#post1222527

Has something changed since then?

The only reason I would do a cam is to get the lobe...


Justin

Scotty

I know what you mean. The first time I was concerned was when I was under the truck and put my hand on the tank while moving around under there...Quick reflex off the tank and I was thinking...DANG was that hot!
I had just a bit over 1/2 tank and had just gone from Saskatoon to Regina...mostly flat land and at about 70 mph...empty 150 miles roughly. The next time I did a run with less then 1/2 tank I stopped at my friends and did the infra red reading.

Next time I became concerned was when I opened the fuel cap and steam rolled out.

I had 1/4 tank and was going to top up the tank...towing heavy...was on the freeway in the USA about 300 miles worth.

I think the VP and the CP3 have their own regulator so to speak so no matter how much fuel you try and pressure into them, a good part of it is going back to the tank. I am not sure why it is so super heated in the CP3 as I always thought the big pressure [which can equal heat] was when it went to the common rail. More to learn.

Scotty

crobtex

Has anyone seen a VP44 failure shortly after installing a pusher pump, such as my FASS II?

greenworks

Granted I am no expert in the Vp, the way I see this delema is that the vp uses fuel to cool the internals and any heat in the case the fuel, it uses what it needs at that time sends the rest back to the tank. I have been talking of a inline fuel cooler for a while and probably before next summer hits will be runnning one. I have also talked to several vp knowledgable people to which I take all there info with a grain of salt, which is very simialr to some of the info I get from here. From what I have read and researched 30 psi won't hurt anything and combined with a fuel cooler to me seems to be a good setup, I also am convinced that the heat and cool cycles on the electronics will happen regardless unless the upgraded blue chip is installed. I take the 30 psi in stride... my thinking is I have 2 carter 4601 pumps inline with a oil pressure switch on one to prevent hard starts, the beauty I see is that if on a long trip one goes down I still keep truck being it will drop from 30 psi to about 15 psi at idle still within the safe boundary, rather than being stuck or forced to drive with no lift pump help.The other thing is with what I run at wot i can see a drop of sometimes 10 psi with two pumps and scottys maxflow so one pump could not handle the flow and I have never been one to stick all my eggs in one basket ie FASS. One thing I should mention is that I wouldn't run 30 psi without a low restriction line and no banjo's.... friction equals heat and forcing 30 psi through banjos to me means heat build up. But as with most of this thread no actual facts just what makes me feel like I am protecting my investment

HOHN

Well, then, I would be just happen to be completely WRONG in how I remembered that!

Diesel-Dan

Fuel Pressure is important for the VP44. You dont want too much when tring to start due to the pump likes low pressure to start with. If you have a big pusher pump...and you have high pressure before the engine catches....it might take a bit to pop off.....if it even pops! I have heard that anything over 25 PSI is not good on the VP44....it may work...but for how long?

The bigger lines and bigger pumps increase fuel volume and pressure. If you have more volume of fuel, you have more fuel to use to disapate heat...even if its in the line still. Also it gives you a reserve for any spikes that might be seen in the fuel system.

IMHO, I feel that if you can keep your pressure above 10 PSI @ WOT....you are FINE. No matter what you use for lines, pumps, whatever. Just be able to monitor your pressure to make sure what ever you are using is working 100% of the time.

greenworks

[QUOTE=Mudinford]I have heard that anything over 25 PSI is not good on the VP44....it may work...but for how long?

QUOTE]

Here is that number again but where did you here this? As stated before in this therad we all can agree with the minimum pressure but where is the limit for high pressure. I have talked to BD fuel department and they have never had a vp blow seals and they have guys running near 50 psi for some reason, but again no solid evidence just them talking, I do know that in their fuel upgrade kits they state that fuel pressure can be between 25-32 at idle psi with the two pump setup.I would think that if that was too high and it would blow seals they would get alot of warranty issues and possible law suits due to the problem.

RowJ

FWIW...Thought I would try this...as a test.

Just got back from a 4 day trip up to Grand Jct, Colo., and borrowed a heat gun from work.

With my tank full...went 400 miles..non stop, at gross wt, 75 mph, 85 * OAT. Pulled over and immediately checked tank temp with an Infrared Heat Gun.

Readings on the bottom of the tank ranged from 97* to 102*....1/3 tank left.

I know Scotty had other problems. Just thought this would be good data to list...and I was curious.
My fuel pressure reads 14.5 psi at idle.

JDGnut

As anyone with a good scanner looked at the fuel temp??? There is a fuel temp sensor inside the VP.. I have watched it on tractors using the VP.. but the scanners I have played with have not shown the fuel temp...
Anyone looked????
Bryan

HOHN

Bump..

I spoke with a "significant" person in the diesel game and gleaned some interesting info:

Guys sustaining over 30psi are seeing premature pump failures.
Guys running 30psi are seeing 10hp more on the dyno.


Interesting for sure. I've been reading a lot lately on FP and the RASP system. The RASP is setup to run any fuel pressure from 10-50+.


The more I read about the RASP, the more I like it. I saw it firsthand at LaserBob's and the quality is like nothing you could imagine. Top-notch is an understatement. More like work of art in CNC glory! I like the fact that it's mechanical and has proven to be quite reliable.

There's one thing that's even more significant: it varies fuel delivery with RPM. Your electric pump can't do that. The electric pump is off or on (unless you have a high-end digital PWM pump controller, which most do not), and this is not optimal.

At low engine speeds, you want low fuel flow. Pumping more fuel than necessary is a sure way to have hotter fuel and less effective VP cooling. Your engine is telling you something when it's hard to start at 25psi.

As load and RPM increase, you want more fuel delivered. The RASP can do this. It can be setup to idle at 10psi, and then up to 16psi at peak load-- perfect, imo. YOu can set it up to go up to 45psi, but I think 15-16 is perfect at WOT.

It's expensive, yes. But at least you get what you pay for . I'd sooner pay $600 for a RASP than a FASS or AirDog.

jmo, not trying to argue.

RowJ

10 hp more compared to what? Stock system pulling down to 5 psi at WOT? OK.

10 hp more than my FASS...maintaining 14 psi from idle to WOT?

Would question that....unless all the data on by-passed fuel at 14 psi is mistaken.

Not trying to argue either....just looking for more details.

RJ

HOHN

That's what I took it to mean. I can't see how a RASP at 14psi could make even 1hp more than a FASS at 14psi..

greenworks

Are we afraid to point out a our sources now, I think we should include where the sources are coming from to get a experince asset with the comment

newriverSpecon

Should make less. It is going to take some decent power to turn the RASP.

Randy

HOHN

Source: Stephan Kondolay. I'm hesitant to say sources because 1) he didn't ask to be quoted, and 2) if someone doesn't believe me, they don't believe me. Anyone think the Kondolays know a little about diesel performance? I respect them for their honesty and willingness to shoot straight. so....

Anyway-- YES, the RASP does take some engine power to drive. But is it any less than the increased alternator drag required to power an electric pump??

The I think the electric vs mechanical is a non-issue with parasitic loss, as they're about the same and relatively insignificant, imo.

Your thoughts?