1050 ccs of fuel!

[BushWakr - RIP]

Guys, I'm a bit of a rookie (read rube) when it comes to this level of things, but, I wonder if Piers will have anything to add when he returns from this weekend.

He was going to take his truck 'pulling' this weekend to see how his newly reworked 160 P7100 performed.

Apparently he has given some thought to the fuel supply/duration/ and other sneaky things that have resulted in his latest brainstorm. I won't repeat what he told me but I notice some of the things mentioned in this thread that kinda jive.



Just a thought, cast no stones please.



Still learnin thanks to ya'll



Bob

 

[Don M]

You can read the post I put right below Power Wagons on the second page. The time in milliseconds to inject the fuel at 2000 rpm is 1. 25 in a 4 stroke diesel engine. After this the piston is already moving downward in the cylinder and you are too late to effectively burn the fuel after this. Raise the rpm even higher and watch the 1. 25 milliseconds you thought you had erode even further.

Big injectors help some, but as atomization decreases you can actualy loose power again. Fueling amounts do not run linear to HP amounts. Forget what you were learning as the cam plates and larger injectors were going in and you were seeing HP numbers come up. After so much you run out of time to inject any more fuel.



The pump stands use 3mm ID lines and a test nozzle sized to calibrate the fuel curves/amounts for a stock fueling level.

The data is extrapolated to figure the proper amounts for all rpm ranges. Once we change things... thats out the window. A pump that makes more fuel does not always mean more HP than one that makes less after we begin to get into the big HP numbers.

Extra fuel that cant be used is just extra fuel.



Don~

 

[KLockliear]

No explaining necessary; for the disbelievers, here's the printout from the test stand:



#ad




And Piers had NOTHING to do with that pump, or the others that we sell and run.

 

[Pthomas]

hey Joe tell us about those secret custom injectors! only kiddin

 

[Strick-9]

Well put Joe! LOL! Exactly what I've been wanting to say.



I started this thread because I feel that number (1050cc's) was a major accomplishment for myself. It took a lot of studying and learning about the P7100 to get there. I spent many hours in the shop tinkering and even had to hire out some of the custom machine work.



I'm excited to know that I approached Lawrence's fueling level all by myself. Granted I'm a few months behind him. It's still exciting.



This is just a tiny piece of a very large puzzle. And I'm missing the rest of the pieces. Not quite sure why everyone seemed so threatened and confused by a single number.





-Chris

 

[HoleshotHolset]

Nice work Chris!

This thread did confuse me at first... . but now I want all that fuel in my little `ole 160 pump.....

Time to go out and buy a spare P7100 and take it all apart and probably never be able to put it back together again... . haha

Matt

 

[Deezul1]

Hey Chris, I want to meet you on Valley Mills at a stop light. I will wave as you go by but you wont see me cause of all the smoke LOL. Then with you, Cord, Cody and me we can give the neighbors another smoke show, kinda get even for the boom box guy.

 

[BushWakr - RIP]

Don M, gimme a hand here will ya...

If the 'given' time for the injection process is as you mentioned in your example 1. 25 lets say, and you increase RPM thereby reducing your injection window, why can't pop-off pressure be increased to compensate?

Is it just too much of an increase to compensate for?

Is the limits of mechanical release reached?

Were am I off track here?



KLocklier,

Since I seem to be only one who mentioned Piers, I'm assuming that your comment was for me. I'm not quite sure were that came from to be honest.

It must be one of those 'lines' got crossed that people talk about.



geezus... . that'll teach me for asking/commenting I guess...



Don M, now that I think of it, if my question is outta wack, don't worry about it.

bob

 

[Don M]

Bob,

Increasing pop pressure will close the window even more.

Higher pop pressure will make the injector open later and close faster, if you are speaking of injector pop off pressure.

Maybe you mean injection pressure, like from the pump itself?



The window I gave in milliseconds is for roughly 30 degrees of crank rotation.



The HP limits are not reached yet. There is still more power on the table, I still have yet to find it though



Don~

 

[BushWakr - RIP]

Yep, thats what I was trying to say Don, thanks.

In my first post, which seems to have gone wrong somewere, I was referring to a couple remarks made by Pthomas when he mentioned things like. . "WHEN factor. . timing, governor operation etc" and Joe D's post... . "AVAILABLE to the injector for a period of time... "

That put me in mind of another conversation I had about getting enough fuel to the injectors/engine and having time to do that.

Then you mentioned what I called injection 'window'.

So, if you can supply the fuel (volume) to the injector, won't raising the supply pressure improve your atomization, and speed of injection into the cylinder?

Second, would raising the supply pressure enable you to increase your injector 'pop' pressure without too much loss of 'window' opportunity?



I'm honestly trying to learn here...

Thanks again, bob

 

[KLockliear]

Originally posted by BushWakr

KLocklier,

Since I seem to be only one who mentioned Piers, I'm assuming that your comment was for me.

Nope, it wasn't... it was for Gene (Sled Puller).

 

[Power Wagon]

Originally posted by Don M

Bob,

Increasing pop pressure will close the window even more.

Higher pop pressure will make the injector open later and close faster, if you are speaking of injector pop off pressure.

Maybe you mean injection pressure, like from the pump itself?



The window I gave in milliseconds is for roughly 30 degrees of crank rotation.



The HP limits are not reached yet. There is still more power on the table, I still have yet to find it though



Don~

What you run into is that the pump cannot make infinite pressure. Diesel is compressible, and the pump is only good for just so much, and after you reach a given point, the pump just tends to leak more and the pressures don't really climb much.



If memory serves, the P7100 is good for some 20,000 psi or at least in that neighborhood. If that's all you can generate, then 20K PSI will flow ONLY so much fuel through a given injector. As you speed up, the time the pump is pumping gets less and less, and so too, the amount of fuel you can flow through the injector at the maximum pressure you can generate will fall.



More holes, bigger holes (only works to a point, then the fuel just dumps out the tailpipe), will get you more fuel flow.



The VE pump on the 1st gen trucks has a larger plunger than the P7100 does. Theoretically, it can pump more fuel than the P7100 can... But it lacks the ability to generate the pressures needed to flow big amounts of fuel, which is why you see relatively low horsepower limits on VE equipped engines. Those who crank the VE way up with the fuel screw just inject fuel for longer and longer durations, which means a lot of fuel at the end of the injection is too late to make power... and just smokes. This is what's happening again, just at a higher power level, with the P7100.



If you're REALLY determined, custom build a cylinder head and pistons with 2 injectors, 2 injection pumps, and c ustom built injectors. You could make more horsepower without smoke (in theory) than you can can now doing that, but the engineering involved would be a daunting task... something that would strain the abilities of Bosch, Cummins, and MIT all put together.



The VP44 is supposed to be able to make more injection pressure than the P7100, I believe, so theoretically, one would be better off starting with IT not converting... . So how's that for a connundrum?

 

[Sled Puller]

Originally posted by Power Wagon





If you're REALLY determined, custom build a cylinder head and pistons with 2 injectors, 2 injection pumps, and c ustom built injectors. than you can can now doing that, but the engineering involved would be a daunting task... something that would strain the abilities of Bosch, Cummins, and MIT all put together.

Been done,except with one big pump, 12 cyl on a 6.

 

[Power Wagon]

Originally posted by Sled Puller







Been done,except with one big pump, 12 cyl on a 6.

Really. A custom built pump camshaft?



One needs to have the injectors flow timed together to get the fuel in during the effective injection window...

 

[Cummins Corvette]

I'd throw in an 8. 3 long before I went to the trouble of 2 injectors/cylinder. Man, you can't get THAT much air in there, geeze, can you say 200 pounds of boost? How about three intercoolers? Where you gonna sit?