Bushy

This is most likely one of those times when my mouth should be shut, but I've never shy'd away from proving my stupidity or sharing so..... Does high volume fuel flow create fuel line heat in high ranges......would larger lines be an answer to helping the VE attain higher HP #'s as much as bigger injectors for example...
The larger nozzles will release a higher volume of fuel, faster. The heat would be generated by the pump cycle and pressure.
It's not the actual movement of the fluid but the process of pumping it that generates heat.... Look at the charge air system, that is the process of pumping/compressing air... and the effect/necessity of the intercooler on that process.

There are some more answers here, it needs a tad more thinking and such.
Maybe duty cycle, pump stroke, supply pump pressures, high pressure side/delivery valve combinations, cam plate lift,overflow restriction alterations,...

For example, the low pressure(delivery) side... the pressure control valve is connected through a passage to the upper outlet recess. It is a spring loaded spool-type valve with which the pump's internal pressure can be varied as a function of the quantity of fuel being delivered.
If fuel pressure increases beyond a given value, the valve spool opens the return passage so that the fuel can flow back to the supply pump's suction side.(*Note* what other item shuts off the return fuel flow and effectively raises the internal pump pressure if only for a short time?)
If the pressure is too low, the return passage is closed by the spring. Lastly, one other item I mentioned is in play here...

The overflow restriction... It is screwed into the injection pump's governor cover and connected to the pumps interior.... now,
this thing permits a variable amount of fuel to return back to the fuel tank through a narrow passage. For the fuel, the restriction represents a 'flow restistance' that maintains the pressure inside the injection pump. Being as inside the pump a precisely defined pressure is required as a function of pump speed, the overflow restriction AND flow-control valve are PRECISELY matched to each other.
Now, after all that mouthful, I can see dzlpwr's point..... the effectiveness of this would HAVE to be determined on a pump stand.

See were I'm going with this.....

There are a number of other items that merit investigation if we want to hit high HP numbers and stay with the original 1st gen equipment like the VE.

edit: I should also mention that I've tossed out ideas or thoughts prematurely in the past and while some have been right (lucky?) some have been entirely off base, so I'm trying to atleast have some grounds for commenting, before doing so. It's hard to know whether you're helping or hindering sometimes guys. Recently I've decided to try and research a little more or think things thru a bit more than previously, but at the same time, if there's a bunch of us thinking, investigating, testing then more gets done, faster.... what to do, what to do.
Ok so that's why I tossed out this idea above. Basically from an interest of more heads are better than one...


bob.

Monty

[quote author=Bushy link=board=9;threadid=11000;start=0#104946 date=1045294499]
This is most likely one of those times when my mouth should be shut, but I've never shy'd away from proving my stupidity or sharing so..... Does high volume fuel flow create fuel line heat in high ranges......would larger lines be an answer to helping the VE attain higher HP #'s as much as bigger injectors for example...
The larger nozzles will release a higher volume of fuel, faster. The heat would be generated by the pump cycle and pressure.
It's not the actual movement of the fluid but the process of pumping it that generates heat.... Look at the charge air system, that is the process of pumping/compressing air... and the effect/necessity of the intercooler on that process.

There are some more answers here, it needs a tad more thinking and such.
Maybe duty cycle, pump stroke, supply pump pressures, high pressure side/delivery valve combinations, cam plate lift,overflow restriction alterations,...

For example, the low pressure(delivery) side... the pressure control valve is connected through a passage to the upper outlet recess. It is a spring loaded spool-type valve with which the pump's internal pressure can be varied as a function of the quantity of fuel being delivered.
If fuel pressure increases beyond a given value, the valve spool opens the return passage so that the fuel can flow back to the supply pump's suction side.(*Note* what other item shuts off the return fuel flow and effectively raises the internal pump pressure if only for a short time?)
If the pressure is too low, the return passage is closed by the spring. Lastly, one other item I mentioned is in play here...

The overflow restriction... It is screwed into the injection pump's governor cover and connected to the pumps interior.... now,
this thing permits a variable amount of fuel to return back to the fuel tank through a narrow passage. For the fuel, the restriction represents a 'flow restistance' that maintains the pressure inside the injection pump. Being as inside the pump a precisely defined pressure is required as a function of pump speed, the overflow restriction AND flow-control valve are PRECISELY matched to each other.
Now, after all that mouthful, I can see dzlpwr's point..... the effectiveness of this would HAVE to be determined on a pump stand.

See were I'm going with this.....

There are a number of other items that merit investigation if we want to hit high HP numbers and stay with the original 1st gen equipment like the VE.

edit: I should also mention that I've tossed out ideas or thoughts prematurely in the past and while some have been right (lucky?) some have been entirely off base, so I'm trying to atleast have some grounds for commenting, before doing so. It's hard to know whether you're helping or hindering sometimes guys. Recently I've decided to try and research a little more or think things thru a bit more than previously, but at the same time, if there's a bunch of us thinking, investigating, testing then more gets done, faster.... what to do, what to do.
Ok so that's why I tossed out this idea above. Basically from an interest of more heads are better than one...


bob.

[/quote]

Good post Bob,

One thing to remember about fuel lines is that if you go to a bigger line, the pressure will be the same but the volume of fuel is different. This will make a change in timing because the fuel is now slower getting to the injector. Just like going to a smaller line with less volume, this puts the fuel sooner into the injection cycle. You will always have heat in a pressurized fluid moving system. Pressure is caused from some type of resistance in a component and whatever is moving the fluid through the system, the lines thereself, fittings etc. You cant have one and not the other. Along with resistance and pressure, you get heat when a fluid is moving accross some other component.

On most mechanically injected engines. Changing to a smaller return line will let you gain more HP. This is because the fuel stays longer in the injector and is pressurized at a higher rate and a longer time than the line that it was replaced with. But, you WILL see a big loss in mileage.

Jim Shulmister

I dont really understand the heated fluid thingy here. The charge air releases heat easy because the heat from a large area is concentrated into a smaller area. (ex- you have a smokey room. You can still see from one end to the other but the smoke is noticeable. If you pumped all of the air from that room into a small clear box, you could not see thru it because of the concentration of smoke.) Now instead of smoke think of heat. If you had all of the heat from that room pumped into the box you would see a giant increase in temperature.<br> The fluid,(fuel) which is not compressable could not react the same as the air.It would only have heat transferred to it, not multiplied within it.The excess fuel (injector spill) is mostly returned to the tank and cools the injectors. More fuel volume should result in more cooling.<br> -RATCHET-

Monty

Anytime fluid is moving accross a compenent and has pressure due to resistance. It will create heat. Have you ever noticed why hydraulic companies do not make many 90* bends in there systems? Heat goes up due to the added resistance in the system and the speed goes down.<br><br>Pneumatics and hydraulics are somewhat different. Air is heated when it is compressed. Fluid is heated when it is moved accross a component.

Jim Shulmister

Ok, got it. I have several forklifts and the hydro fluid does get quite hot from use now that you mention it.<br> -RATCHET-<br>

Bushy

I agree that the process of moving across/thru a surface causes heat, just like shoveling snow... that very process cause a slight increase in its temperature. I would think that the process of pressurizing the fuel in the line is the primary cause of heat generation, with flow resistance a smaller contributor to the overall fluid (in this case fuel) temps in the lines.<br>Now, with injector lines they must be extremely closely matched to what is called a 'rate-of-discharge' curve. They must have no sharp bends and should be secured at specific intervals. The precise placement of the securing points may well be due to the need to moderate the &quot;harmonics&quot; of the delivery pulse and the reverse pressure wave(s) caused by the closing of the return-flow restriction in the delivery valves.<br>All this is a co-dependent system. If one of the components are changed, then it may well be that under higher demand/extreme condtions they will cause progressive problems throughout that system.<br><br>So for example, what defines whether the rate-of-discharge curve has been altered??? Larger injectors?? Pump timing???<br>Fueling increases/decreases?? <br>Does this even come into the equation??? <br><br>Am I still on earth... ;D<br><br>bob.

1stGenBikeHauler

<br>I figured I'd jump in on this and see if I could help a bit.<br><br>The main source of heat in a system is not the pressurization of the fuel but the inefficiency of the pump. Piston pumps such as the VE are fairly good at turning input power in to pressure. <br><br>As far as restrictions go when there is a restriction in the system the available power is redecuced. That bit of power has to go some where. It is turned into heat at the restriction caused by the fluid releasing this available power.<br><br>If you had a 1hp motor turning a hydraulic pump that was 90% efficient you would loose .10 hp into heat at the pump.<br>.10hp (1HP=2524 BTU/HR) = 252.4 BTU/hr heat generation at the pump.<br><br><br>

1stGenBikeHauler

<br><br>I also have to disagree with the idea that when larger lines are installed it will require timing changes. The lines on our engines are nothing but columns of incompressible fluid. That is why CTD's will not run with air in the lines. Since the fluid in the line is not compressible its like pushing on a solid bar. If you push a small steel bar 1in the end will move 1in. If you were to push a huge steel bar on one end the other end would move 1in. The only time the line will affect timing is if it expands with pressure (effectivly simulating a compressible fluid), or if is small enough or bent in a way that will restrict fluid flow.<br><br>To add to what I was saying above about heating hydrauic fluid with pressure drop I found the equation for that .<br>HP=1.5*(PSI drop)*GPM and then convert HP to BTU/hr<br><br>The question then comes...why does air from a tire nozzle feel cold and not hot. Because it is a gas and has its own set of properties.<br><br>Hope I dont sound like a knowitall Jack@ss. I can back up what I am saying Im not making this stuff up.<br><br>MD<br><br><br><br><br><br><br><br>

Bushy

Hmmmm...<br>Ok, based on your comment that the piston style pump like the VE being fairly good at &quot;efficiency&quot; then were would we look and, at what stages of the pump/supply phase will we find room to improve on the overall ability of the pump to deliver fuel. Especially if we are trying to have a pump that is rated for say, 230, 260, or even 300 HP???<br>It's been commented by another CTD'r that a pump was built to a rated HP of approx. 300HP. That pump, during usage, (and under some load) blew the lines on the truck. Also the fuel lines and the fuel in them was so hot that they were barely touchable, and the fuel was so hot that detonation was a real potential problem.<br>If we assume that there is 'good efficiency' in the VE, then are we now looking at DV's, inner fuel line diameter, internal nozzle restrictions, pop-off pressures, or what?? All of the above???<br><br>OR did I take an unmarked exit off the highway...<br>Geeezzz, I need to get my water wings, this pool is too deep...<br><br>Bob.

Jbolt001

Just some thoughts/ questions........<br><br>A given amount of HP requires &quot;X&quot; amount of fuel<br><br>The VE pump is a mechanical pump timed to the engine. The rotary piston has a fixed amount of fuel it can push each cycle. This is set by the physical volume of the fill port, fuel groves and piston stroke. The rotary piston pushes the same amount of fuel each cycle regardless of RPM and the fuel delivery is regulated by the throttle/governors position of the control sleeve. <br><br>Excess fuel is bleed off through the return on the pump and the injectors. I understand there are a number of other things going on related to internal pump pressure etc. but as I see it with a fixed amount of potential fuel what we are trying to do is maximize the available fuel. A certain amount of excess fuel is needed to maintain proper internal pump pressures and coolant for the pump. It seems to me the closer one comes to maximizing the available fuel the less fuel there is to provide proper cooling and probably a number of other factors.<br><br>I wonder if there are different rotary pistons for different applications? Bigger fuel grooves, different cam lift etc.?<br><br>Jay

Bushy

There we go........Jay, exactly what I was wondering...<br>Is the redirection/reduction of return fuel, so it can be used as supply volume, causing extreme temps in the system...<br>I firmly believe that we do not need to go any &quot;alternate&quot; VE pumps to achieve significantly better HP numbers. We DO need to look at the entire cycle from low pressure (supply side) right thru to injectors as the end of the &quot;system&quot;.<br>Now, nascar made some pretty darn good numbers with his pump, which was pretty much all &quot;self done mods&quot;.<br>However, I think even mark will tell you that it was really pushing the pump to it's extreme limits, and lifespan would likely be seriously be comprimised.<br>So, were else can the system be tweaked to achieve the same or better results, and alternately slow the accelerated 'genade time' on the pump..???<br>Mixing components from other pumps? Modifying existing components? Ideas here guys....<br><br>Bob.<br>

Redleg

Some sort of inline fuel cooler prior to returning to the pump?<br>Far Fetched?

1stGenBikeHauler

<br>I am no VE pump expert by any means but I would it be possible to create a high flow cooling loop for the pump itself?<br><br>What if you added fittings to the VE case and ran a seperate high capacity in/out loop. Ahh but you have a high case pressure you have to mantain...ok use a regulator setup to keep up the correct pressure. <br><br>Go huge... pump tons of diesel though the case of the VE pump. Dont rely on the dinky little lines to carry all that heat away. Use a 1/2&quot; line....3/4&quot;...what ever it takes to get rid of the heat. That way you use the 30 gallon reservior under the bed as a liquid to liquid heat exchanger.<br><br>This would make the pump live longer. The heat is coming from there...get rid of it there.<br><br>I would suspect that the P pump is helped by having the relatively cool engine oil plumbed through its case.<br><br>Thoughts???<br><br><br>

hdm48

I believe the answer to all these questions will be found under the name 'Ideal gas law&quot;. Some basic rules listed in the laws of thermal dynamics will help too. Fluid dynamics fall in here too.<br> Plus, I believe the inner diamiter of the tubeing is not the issue. I would think the wall thickness of the tube is in question or, the material it is made of.<br> If you guys ever have the chance, try doing an infrared scan while the engine is running and watch as the pressure pulse travels the length of the tube.<br> I have not done a flex test of a tube yet. That should be interesting.<br> Interesting subject though. keep it up. Good reading.<br><br> dave

hdm48

Oh, I forgot. Just for you Bob.<br> Ideal gas law--PV=nRT=NkT<br>it's real simple when you think about it.<br> P=pressure<br> V=volume<br> T=temperature<br> R=universal gas constant =8.3145 jules<br> n=number of moles<br> N=number of molecules<br> k=boltzmann constant=1.38066x10 to the minus 23rd<br> NkT is not as important as nRT, so you need to know the molecular make-up of the fuel and how much H2O is pressent in the fuel. <br>next class, we will discuss the basic laws of thermal dynamics.<br>take notes, there WILL be a test