Question for dzlpwr

[cerberusiam]

I am going to throw one more thing into the fray about HP ratings. My physics knowledge is a bit hazy so if I missed something correct me. Bob, I know how you hate formulas so I condensed it something I hope is clear.



If HP is defined as the amount of energy expended to complete a unit of work, a unit of work being moving a mass a certain distance, and expending energy creates heat, would a logical conclusion be HP is a measurement of heat created?



If torque is defined as the amount of energy needed to move a mass thru a distance in a period of time, wouldn't this measurement be more meaningful in relationship to the usage of our trucks?



With the previous being true, It is easy to see how a 160 HP 400 ft/lb vehicle would walk away from a 300 HP 250 ft/lb vehicle in a practical application such as dragging around a 10,000 lb trailer. For practical purposes, wouldn't a torque rating be more useful than a HP rating?



A quick word on DC and HP ratings. Before DC was DC and mechanics were more than parts changers, I was told by the mechanics and engine builders that the HP ratings were at the rear wheels. If that was not true, if that has changed, if it doesn't apply I stand corrected.



Now that I am way out on a limb, somebody hack it off. I am a glutton for punishment and ridicule.

 

[JLEONARD]

Sorry guys, I don't think the other web site is even worth a comment from me. I guess if they are that amused then we have done well.



Personally I'd rather learn than ridicule!

Jay Leonard

 

[jbolt]

Group-



Sorry if dropping the other post on this board upset anyone but it was directed at this thread. Weather you agree or disagree with it and those who wrote it I felt that right or wrong it would further the discussion...



I can't say I care for or agree with the demeanor of the other thread but I do believe some productive discussion can be had from it.



Jay

 

[jbolt]

What about the delivery valve?

I'm wondering what effect changes to the injectors and fuel lines have on the relationship to the delivery valve.



Wouldn't it stand to reason if we install larger injectors and increased the line size to allow more fuel the delivery valve would need to be matched accordingly? Maybe this is another item that is CPL specific?





Jay

 

[Power Wagon]

Let me put some perspective on some issues that I have seen coming along in this thread.



1. Advance. The injection pump can advance A LOT. There's hydraulically and mechanically lots of room. However, in the pump in your truck, the total advance is limited by the length of the piston. It moves from being solid against the "power" side to solid against the "end" side before the pump reaches 2500 engine rpm.



In order to take advantage of the increased RPM's, you need to inject at the correct time. This means that you have to allow for "burn" time in the cylinder, and the mechanical "lag" which occurs as the pressure wave from the pump travels to the injector, and begins spraying.





The faster you go, the more the pump must start ahead of optimum to achieve actual burn at the best time. However, with emissions in mind, both the initial timing, and the amount of advance are less than optimum to keep combustion temperatures and NOx down. Increasing both travel and initial timing will improve economy and get more horsepower with no change in fuel.





2. Purpose of twin turbo and airflow mods.



It is entirely possible to squeeze enough air into the engine to burn all the fuel the VE can pump. However, the losses involved in generating the massive boost, AND the pressures involved would damage the engine (blow head gasket, etc), will subtract from the horsepower you can make.



Thus, the purpose of using parallel twins, for instance, is to have lots of airflow with as little back pressure as possible. This is the equivalent of "free" horsepower. Someone, not too long ago, did a dyno run with various turbo housings, they found that from a hx-35/12 to an HX-40/16 could easily make 30 to 40 horsepower difference. This is MOSTLY accounted by the reduction of pumping losses in the engine. All this extra air in the engine WILL result in higher cylinder pressures, so some reduction in compression ratio is in order.



3. RPM!!!



Rpm is a magical factor. If you do not change the amount of fuel flowing, but increase the RPM, you increase horsepower.



For instance, a 215 HP engine at 2500, assuming no other losses, and maintaining the same torque (not really feasible, but you have to use the theory to demonstrate), cranked up to 3400, will make 292 horsepower.



Thus, to break 325 HP, it's not necessary at all to have massively more fuel, but merely to have a small marginal increase, reduce your pumping losses in the engine (cam, porting, twin turbo, intercooler, exhaust, intake, etc), open the injectors enough to allow the fuel through, and speed up to 3400. If you can make 230 to 250 HP, just the reduction of losses and efficiency (efficiency is accomplished with injection timing fixes - mainly, increased mechanical advance in the pump), 325 is an easy goal.



And now, misc observations...





Piston scuffing is generally caused by either overheating the piston, or putting raw fuel on the walls.



Both of these suggest either a lack of airflow, or injector design not compatible with the combustion chamber OR the amount of fuel being shoved through them.



Too large of holes, too much fuel, and you'll impinge the cylinder wall with the injection stream. You need more holes, and small ones.



The intake system is abominable. My thoughts are to build a log-type intake manifold with individual drops to each cylinder, above and through the plate that now serves as the top of the intake manifold.



Just keep thinking

 

[cerberusiam]

The guy that built my pump said he needed the correct delivery valves for the pump model to calibrate the pump. I had two sets and originaly gave him the wrong ones. He said they would probably work but didn't want to warranty the work if he had to use them.



If I understand the descriptions correctly, the relationship is between delivery valve, line pressure, and injector pop-off pressures. All other things being equal and diesel a liquid that does not compress easily, line size should not affect fuel delivery. Nor should a larger injector change anything other than putting more fuel into the cylinder faster. The pressure generated with any size line before the needle lifts off the seat in injector would remain constant but then would drop quicker due to larger area to inject thru.



What would happen if the delivery valves were changed to increase fuel flow and\or the injector needle bore was sized larger... ... ... .

 

[jbolt]

What is a HY-9 turbo? Holset shows a HY-30W, 35W & 55W?



I haven't given it much thought but would parallel turbos fit? With the turbo in the center of the stock manifold there is barely enough room for the exhaust as is. Just trying to picture the setup.



I'm thinking on a parallel setup that two separate intercoolers would be ideal? At what point should the turbos air flow be reintroduced to each other?



Should each turbo have a separate exhaust system? Could they be collected together in a single pipe and work properly?



As far as intake manifold mods go the stock lines interfere with a large portion of the area directly above the intake. That does not leave much room to work with without changing the lines. I've wondered how some have adapted the Banks twin ram to the 1st Gen.

 

[BushWakr - RIP]

As PW mentioned early on, the parallel twins is something he has kicked around for a while...

I know there is one of our guys who has tried them and had difficulties.....

I believe that the primary problems to overcome with a small parallel twin setup is, of course custom exhaust manifold designed to feed 3 exhaust ports to one and 3 to feed the other (turbo I mean)

Now, even the small turbo's need a certain volume of exhaust gas, at an appropriate temperature, with sufficient pressure (read velocity maybe?).

I think you need all 3 of those factors in order to work effectively.

You can always go down in exhaust housing size to make up for some of that, but at some point you hit the top of the 'curve' in terms of losses due to drive pressures again, and you're back were you started from, only you have two turbo's running nasty drive pressure because you needed a 6cm housing (to illustrate point) to make it spool.

Remember, I have no personal hands on experience with this type of setup so I'm just thinking out loud here.

The fellow who is working on this will speak up if he wants too.



I am a bit confused about something you mentioned PW, and that is I was always under the impression (right or wrong) that fuel made RPM. More fuel, more RPM, hence the run-away condition that can happen... the opposite being defueling results in no more RPM being developed. Were am I going wrong here???



Maybe point me in the right direction here if you would... .



OH, BTW, formula... ... thanks bud... I really do suck with formula's

9000 strokes per min !!! :--)



Just as an FYI ... turbo's don't usually go from 100,000 RPM to

-50,000 RPM. It wouldn't be called barking, it would be called blowing up (in fun now, in fun. ) Otherwise it's compressor stall.



bob.

 

[roadhawg]

Hugh Mcginnis

How to design and build a turbocharger system. Excelent reading! He talks about the time between pulses of air on a diesel that is a low rpm engine anyway that they don't make turbine wheels strong enough to withstand the peaks and valleys witch get spread out even farther by cutting the rpm in half to each turbo. I mean each turbo would see half of the pulses one larger turbo sees with exaust pulses twice as close at a given rpm.



Now about the fuel pump. I have been running an electric fuel pump in series with our lift pump for some time. Its a holly and makes 15lbs. I believe this is a measure of preventitive maintenance because our pumps are lubed by fuel.



I also want to talk about some mods I did with a dremmel tool, I increased the high and low idle travel , I believe increasing the low rpm travel decreases the chances of runaway and allows more adjustment with the fuel screw.

Heres one for you guys the afc pin pushes on a plate witch pivots and restricts fuel. That plate has a foot on it witch is missing on mine

:{ this has a similar effect to shortening the afc pin but allowes more travel!

Happy bombing

Eric

 

[Power Wagon]

Originally posted by BushWakr



Now, even the small turbo's need a certain volume of exhaust gas, at an appropriate temperature, with sufficient pressure (read velocity maybe?).

I think you need all 3 of those factors in order to work effectively.

You can always go down in exhaust housing size to make up for some of that, but at some point you hit the top of the 'curve' in terms of losses due to drive pressures again, and you're back were you started from, only you have two turbo's running nasty drive pressure because you needed a 6cm housing (to illustrate point) to make it spool.

Remember, I have no personal hands on experience with this type of setup so I'm just thinking out loud here.

The fellow who is working on this will speak up if he wants too.



I am a bit confused about something you mentioned PW, and that is I was always under the impression (right or wrong) that fuel made RPM. More fuel, more RPM, hence the run-away condition that can happen... the opposite being defueling results in no more RPM being developed. Were am I going wrong here???

Ok, Bob... here's my thoughts.



One: You are entirely correct that it takes gas through the turbo with velocity to spool it up.



There's more than one way to achieve velocity. If you have X amount of gas moving at X speed, then shoving it through a smaller hole makes higher velocity. OR, you can move MORE air through a LARGER hole to achieve the same velocity.



There are two things that inhibit turbo spooling...



1. Momentum... It takes energy to overcome the inertia and spin it up.



2. resistance to turning. There's friction (minimal) and there's BACK PRESSURE on the outlet side... That takes power to maintain that pressure. Reduce the resistance to air entering the engine, make the engine CONSUME more air per revolution, and you will move more air with less boost needed.



And, once you put more THROUGH the engine, there will be more to spool the turbo.



Since you put more AIR through, you can put more FUEL into the engine without boost. Fuel + AIR = heat and more exhaust.



Thus, it improves the engine's ability (heat the exhaust, it expands, creating higher velocity through the turbo... ) to spin the turbo quicker.





OK, a bout the fuel thing.



I'm not sure, I might not have been clear.



The VE pump works by injecting X amount of fuel per stroke.



That's X amount of fuel for each cylinder, for each combustion cycle.



If you get MORE of those fuel shots per minute, you get more horsepower. Raising the RPM makes more horsepower, without raising the amount of fuel for each injection.



In any case, the governor works by putting in all the fuel it can, until it reaches sufficient speed that the governor begins to cut the fuel down. As the speed builds, the governor cuts back the "per stroke" fuel until it reaches the point where there's only enough fuel to maintain the speed the governor wants.



Load the engine more, and the governor raises the "per stroke" fuel shot size.



"more fuel", as in a greater amount of fuel per stroke, makes more torque. If that torque is greater than needed to maintain speed, the engine goes faster. If it is less, then the engine slows down.



So, following this, fuel controls torque... Horsepower is just torque multiplied by RPM.

 

[Power Wagon]

Re: Hugh Mcginnis

Originally posted by roadhawg

Now about the fuel pump. I have been running an electric fuel pump in series with our lift pump for some time. Its a holly and makes 15lbs. I believe this is a measure of preventitive maintenance because our pumps are lubed by fuel.

Putting pressure on the supply side of the VE pump causes pressure in places in the pump that really should not have pressure.



The purpose of the supply pump on the trucks with the VE is to make sure that the supply does not see any strong suction.



The internal vane pump in the VE is entirely capable of pulling fuel from the tank to the pump. However, it tends to leak air into it when the system gets old. PUtting in a low pressure supply pump on the block makes your filter go slighly positive pressure, allowing you to do things like drain water, since there won't be a vacuum on the filter drain. It also makes it possible to prime the system should it leak down, you run out of fuel, or you change filters.



I would avoid running 15 PSI into the VE. You are inviting a leak past the drive shaft into the crankcase.

 

[Wayno]

Well I took the lift pump off my truck about two years ago and put a electric pump in the same place that the factory lift pump was at . I check to see what the psi ratings for the electric pump were but I cant remember but I think they were the same or a little bit more than the factory lift pump ( I will have to check again ) It hasn't given me any problems let . I did notice that it smoked more after I put the electric pump on it but then again I don't know how bad the factory lift pump was or how long it had been getting weak .

 

[Brandon]

It looks like you guys have a really good debate going on over here and I hope something good comes from all this discussion for you guys. There are some things I think I could help you with though.



Cerberusiam- Increasing the injector size increases flow because at engine speed you have a VERY limited time to inject fuel, if you had a long time then yes all the fuel that was put out by the pump would have time to inject before the next cycle, but this does not happen as the injector just can not flow that much fuel that fast so as the pressure in the line was back to minimum each cycle. This is why bigger injectors flow more fuel, it is not just a matter of timing.



PW- the VP44 can also draw fuel, just like the ve, but it is highly recomended not to do this and that the pump should have pressure going to it to prevent damage as found out by soo many other members here. Why would the VE be any diffrent, wouldn't it be better for it to keep fuel goin to it as well??

 

[therabbittree]

mummn the vw ve pumps do not have feed pump. they just use the internal ve pump to suck fuel all the way from the tank... mummn i wonder if my turbo diesel ve vw should get a feed pump hummn. ??? hehe whay max psi for the feed? also for you guys info. . my custom 12mm plunger ve vw pump puts out 212cc per 1000 strokes. . piers's pump guy built it for me 3200 max pump rpm = 6400 engine rpm they suggested timing it at 1. 94 at tdc... ...

so 12mm is the largest stock ve plunger available in any application huh?. . good to know for me. .

and finally i'm doing a p7100 pump conversion on my 89 cummins dodge and now am i hearing right ?. . that my cylinder head might have to be changed, as it isn't nothed for a p pump?. . never heard that before. . is that true?...

thanks

Deo

\x/ hillfolk!

 

[BushWakr - RIP]

Not to worry, if the head casting is in the way for the p-pump, a good die grinder will cure that problem ...



The head could use some porting then, since you're going to the p-pump, you're obviously gonna run a bit 'O fuel thru it...

Touch base with PDR and see what they suggest for that...



Bob.

 

[roadhawg]

More pump mods

Ok here is another one for those interested in more fuel at maximum throttle. the fuel shut of lever on the side of the pump is spring loaded and when it returns to its normal position the tab inside the pump prevents full forward movement of the fueling assembly,removing about 1/10th of an inch really adds fuel at full throttle but you then need to adjust the lever stop with the allen head and jam nut.

I have experienced runaway before from adjusting fuel screw to far but I had a choke cable attached to the fuel shutoff lever and could shut of engine with that from the cab, I still have the cable attached for testing.



I have never dinoed this truck but it pulls harder than my buddies 95 with 4000rpm gsk, 370s, 191dvs, 4" exaust, timing at 16, k&n, and 1000ftlb clutch, afc medium spring, ground fuel plate, and pdr hx35turbo.

I think that these first gens have allot more potential than some people would have you believe!



I am not trying to be confrontational with anyone but I disagree with some of the limits that people have posted about the VE engine because I like to tinker with things and have found many improvements in power that to me have proven that it can make alot more power than what has been posted here!



Some of the group of guys going to school here at osu rode or have driven this truck and we have compared notes, two of that group are tdr members with 2nd and 3rd gen trucks and one drives a ford they will all tell you that they are surprised at how much power can be found in these first gens.

I hope we keep having positive exchanges of information so more people can benefit from having increased mileage and power.



Oo.

Happy bombing!

Eric

 

[roadhawg]

Ford intercooler

Heres one way to get those nasty egts to managible levels but it doesn't fit.

I had to set the end tanks right next to the frame to clear the hood latch on top.

Went to a local exaust shop and had some 2 1/2" to 3" addapters made for the hot and cold pipes so I could use the ford intercooler boots, they are 3" on one end and 3 1/4" were they slip on the intercooler. ford has really nice spring loaded hose clamps!



Next is a 4" exaust, mine changes to 5" after the transfercase and exits in front of the rear tire.

I can still peg my 1500 degree piro in about 3 seconds

 

[BushWakr - RIP]

roadhawg,



You posted "... ... position the tab inside the pump prevents full forward movement of the fueling assembly,removing about 1/10th of an inch really adds fuel at full throttle ... . "



Exactly what "fueling assembly" are you referring to??

Are removing 1/10th" from an internal part?

I've looked at the schematic and nothing jumps out at me that resembles the components you describe, or were those components migh be altered.



I realize you haven't dynoed but have a rough estimation of the current RWHP you think you're currently getting??



Bob.

 

[roadhawg]

Bushy

Somebody posted a color picture of the top of the pump removed to show where to hook one end of the govener spring.

The part i am talking about is the black stop that is horizontal to the levers that the other end of the govener spring hooks to.

Looking from the outside of the pump the spring loaded assembly on the drivers side is the fuel shut-off lever, the shaft that rotates if you manually move this lever is hooked to the stop that I ground about 1/10" of an inch off of to allow the govener spring to pull the assembly farther forward.

I am sorry if the name I used for the parts are wrong, and I hope this description makes sense.

When I said fueling assembly I was trying to describe the levers that are pulled forward to overcome the force from the govener weights pushing back because of centrifugal force.

I don't know the names of the parts and I should do some reading so we can all benefit.



As far as estimating horsepower the truck I mentioned wieghs about 7500 lbs, and my truck is 6300

I think his is less than 400 and so is mine

Maybe I can make it to A dino-day so it can be compared with other trucks on the same dino.



I"m sorry Bob if I can"t make the parts jump out at you by typing them,but I hope this helps.

Eric

 

[BushWakr - RIP]

Hey Eric,



No harm no foul... . I just wanted to make sure I wasn't overlooking something due to definitions... . your description is good and I'll dig into my manual for a look see.



Possibly this is another source of "extra" fuel for some of us who want to put down some good dyno numbers this spring... .



Thanks for filling in the blanks...



Bob.