ok this is just a thought and theres probably a million reasons why i'm wrong but i want to know them....

on a gasser engine when the do NoS fogging.. extra gas is injected in the intake stream also.. because NoS is an oxidizer and its assumed when you get into the high levels that you'll need the extra fuel to even things out..

now we inject propane to helps us get fuller burns or Nos.. to each his own.. no why if you where raising boost or injecting propane/nos into the intake stream why couldn't you also inject diesel? it doesn't have to be at the extreme pressure required to get it into the engine. .and would from my point of view help to create more power..

now bring on the attack as to why i'm wrong.. it's actually what i'm looking for

thanks
Brian

I don't know if I fully understand what you are trying to do here. Are you saying inject diesel fuel into the intake air stream, along with NOS or Propane?

I'm not familiar with NOS or Propane, but injecting diesel in your intake air sounds like things would get real sloppy real fast. You engine would be basted like a turkey with liquid fuel. Gasous fuel you could shut off in a quick hurry, but once you've got liquid fuel everywhere, it sounds like a your just a phone call away. . . 911.

Injecting diesel into the intake path would cause super detonation. It would be like a TDC offset of like 40 degrees!!!

My guess anyhow!

Gas compresses - liquid does not.

Dry gas compresses easily - 'wet' gas requires more work.

Air compresses - Diesel-laden wet air combusts.

Diesel engine runs by controlling injection timing and quantity - Diesel-laden air will combust at some uncontrolled timing event.

Not good - not good, a'tall.

But, hey, to each his own - "knock" yerself out............;)
:cool:

Just one ol' Rural Volunteer Fire Chief talkin' here....Please don't!!;)

There goes another one down the drain! (idea that is)

There's a lot of reasons why you can't do this, but I'll just add my 2 cents to the pile.

Diesels don't have spark plugs to start combustion.
On the compression stroke in a diesel, only air is present in the chamber, fuel is introduced directly into the chamber and the heat that is already present ignites it.

When you have a fuel/air mix entering a diesel engine, you get uncontrolled combustion, the fuel burns as soon as it gets to combustion temp, so on a hot engine, you will get a severe pre-detonation knock.
Propane works OK because it has a high ignition temp and burns much slower than diesel fuel.

NO2 works on diesels, but for the reasons mentioned above not the same way it works on gassers. NO2 on diesels only works as a super intercooler on the intake air temp.

thank you all for your replies and explaning to me exactly why this won't work.. it was something i was pondering.. not something i was planning on doing.. and i knew no one did it and i needed to know why, now i do and it makes sence...

thanks again

Brian

NO2 works on diesels, but for the reasons mentioned above not the same way it works on gassers. NO2 on diesels only works as a super intercooler on the intake air temp. It adds combustable oxygen.

Bagalac,

Why not add water/methanol?

Your diesel would also "run away" on you.

Bagalac, not really a crazy question - I know someone that was working on a water/fuel misting system for a Duramax. I asked the same questions about the potential for predetonation problems but he seemed to think he had it covered. (would direct vs indirect injection matter?) When we talked he had figured out a nozzle and was working on a controller. Don't know if it ever got installed or what the result was, if I find out I'll let you know.

I'd plan on talking to him only on the phone, in the R&D stages, mini.............

You can pre load the air with fuel. The problems are atomizing it and keeping the F/A ratio low enough not to detonate.

The Dmaxes already pre-load the charge using the injectors on the intake stroke (pilot injection)

I've tested it, It works but controlling the flow while getting good atomization is a PITA. Probably 6 months out from getting the controller worked out. Water injection increases the allowable F/A ratio before detonation.

With "pre-loading" the engine seems to run smoother. Go figure.

You can play with it yourself if you want. I used an airbrush to atomize the fuel into the intake for my first tests. Crude, but proof of concept.

Hmmmmmmm.................. I thought plot injection involved injecting a small quantity of fuel early into the combustion cycle\event to get the burn started, whereupon the fuel required for power could then be injected into that burn, and even extended far into the power stroke for added torque.

Pilot injection is modern tehnology applied to Diesel function, but not on the intake stroke, eh?

Why would a PCM need a full revolution of the crankshaft to get a small quantity of fuel into the combustion event?

My bad. Not "pilot", "pre" injection.

Can you post injection timing figures for 'pre'?

Can you post injection timing figures for 'pre'?

No, I'm only going by what I have read. I will look for the reference again.

I did my early intake air loading work on the engine in my Case skid loader (4cyl cummins). The intake is very short and no turbo. I was prepared to plug the intake if it went into run-away from fuel collecting somehow in the intake. Never happened. I never did get detonation on that engine, But I was conservative. I've thought about going back and using a regular spray gun to load the charges.

Spraying into the intake on the Dmax pre-turbo has me concerned about fuel collecting in the CAC and then setting the engine into run away if the collected fuel would ever migrate up the intake to the engine. I read here on the Forum about a mechanic that had one do that when a customer tried to get Dmax to start by pouring fuel into the intake.

I've been working on injecting fuel on my LLY just after the EGR valve. The old air brush trick doesn't work here when the boost comes on. At idle, I have been able to watch the balance rates go down with the Predator though while I preload.

I know at some point detonation will be an issue. I just haven't loaded enough yet to find the line.

FWIW, I think the 6.5 with it higher compression ration will be less tolerant of pre-loading. Maybe MiniSub will let my borrow the Blazer for a night. ):h

All of this is still a work in progress and based on my own (possibly flawed) thoughts. I wouldn't have mentioned it if MiniSub hadn't said something. There is a good chance it will not lead to anything useful. Early results are interesting.

NOS is adding oxygen to the engine, gas or diesel - to help burn the fuel. The A/F ratio must be kept in balance as well, or meltdown will occur. Adding more fuel in a mist does not help the combustion, but adding oxygen does. Water mist is also supplying oxygen to some degree, but not like NOS will. Propane also works, but again you must be careful.

I know of a trucker who mixed diesel fuel with the oil in his oil bath air cleaner one winter. He never got it shut down in time, plenty of engine parts were on the ground.

So adding Meth/water or propane (fuel) should have no net effect if what you are saying is true.

FWIW, I think the 6.5 with it higher compression ration will be less tolerant of pre-loading. Maybe MiniSub will let my borrow the Blazer for a night. ):h

Uhm, I was planning on keeping it in one piece for another 18 months to see what the new FJ cruiser looks like, or perhaps get into a Dmax myself. Since I just saw someone list my identical truck in the classifieds and realized how little its worth ($3,500!!?!!?) perhaps I will need to change my timeline.....(this would be a good place for a boom or poof emoticon...)


All of this is still a work in progress and based on my own (possibly flawed) thoughts. I wouldn't have mentioned it if MiniSub hadn't said something.
Oh boy, didn't mean to :stirthepo

Guess the point was that Bagalac's original question wasn't totally out of left field - there are people thinking and playing around with this concept. Whether or not it is a practical idea for either the 6.5 or Dmax remains to be seen (and will probably cost me an engine to see to it the way things are heading!)

Adding Meth/water or propane will give you more power. I've had diesel farm tractors on dynos while adding propane, acetylene, and pure oxygen. I would be real careful if trying NOS on an already turbocharged engine, I'd be worried about meltdown as I am already packing a lot of oxygen into the engine with the turbo. All contributed to increased power, but with all, you have to watch out how much you add. Simply adding a turbo to a non-turbo engine requires an increase in fuel to avoid meltdown just to keep the ratio correct (and exhaust temp reasonable). Adding the correct water mist to the intake will help boost power and bring down exhaust temps, but everything has it's limits. I believe Heath diesel was getting 300 hp from 6.5 electronic diesels using his water mist system, and doing that by other means is difficult or more expensive.