Power and Smoke?

[Burner]

I can see that the #1 trucks in pulling and the track have TONs of smoke. I think most understand that Smoke = Incomplete burn. So, exactly what is going on here? Is only 1/2 the Diesel burning, is the cylinder flooded, how much Diesel is burning, is it running cooler or hotter, would not smoke be "unused" power?:bang

[Billysgoat]

The CR motors will start to eliminate that, with mechanical injection or cruder computer controls about all you can do is dump the fuel to it. Once you can control ALL the variables with the motor a whole lot of the smoke will be eliminated IMHO. A smoke show is fun to watch, but it does represent unburned fuel that could be producing power, to an extent it will help keep the cylinder temps down, but not that much.

[Burner]

So, with enough air, the fuel isn't atomized that well if you have a lot of smoke? I wonder how much fuel surface area is needed to make a "no smoke" Diesel?

I guess the pilot injection would be a good thing until the piston speed was too high?


.....going on that, what is the remedy for real power without smoke?:bang

[Burner]

........AND meeting emissions, keeping the exhaust temp down. Twins? :confused:

[COMP461]

air Flow


Cylinder Heads And Cams

[diesel_ram_man]

Alot of it has to be just for fun to see, because watching a truck pulling a sled with no smoke is just boring, to me at least.

[Noreaster]

The CR motors will start to eliminate that, with mechanical injection or cruder computer controls about all you can do is dump the fuel to it. Once you can control ALL the variables with the motor a whole lot of the smoke will be eliminated IMHO. A smoke show is fun to watch, but it does represent unburned fuel that could be producing power, to an extent it will help keep the cylinder temps down, but not that much.

Exactly, Cr motors with high pressure injection & complete engine control are the future. I think I seen somewhere that somebody put a P-pump on a newer Dodge, it kinda defeats the whole purpose of efficiency when using old technology. Probably use half the fuel on a CR motor as the P-pumped truck & make the same power.
Thing thats going to be needed is a revolution with the injectors to keep the stock style atomization & fuel pressure in the sweet spot. Enlarging the holes is not the answer.

[Burner]

So the bowl and Injector will need to be changed? I guess higher psi and small holes (more of them) will be the ticket? Gott'a break apart those bonds to get air all the way around each .......

[Billysgoat]

I look for a dual injector setup to become the ticket for the Pro-Mod drag racers who want to compete with the gassers. It's just about the only way I can forsee getting the amount of fuel in the combustion chamber you need to make the serious power, WITH proper atomization for the best burn.

Make no mistake fella's, the smoke shows will have to end at some point, really quick if they want to break into the national level NHRA type events.

[CookCR]

My CR's always gona smoke...how can i smoke out the yuppie bikers without it???

[Burner]

I guess that's what I'm getting at. With all that smoke, how much fuel is actually being used for power?

[hippie]

So the bowl and Injector will need to be changed? I guess higher psi and small holes (more of them) will be the ticket? Gott'a break apart those bonds to get air all the way around each .......

It isn't the molecular bonds you have to break. You have to interfere with the surface tension of the fuel droplets to get the fuel to evaporate quicker; the faster it evaporates, the faster it burns. 2 ounces of acetone per 10 gallons (1280 oz.) of fuel seems to do this quite nicely. 5,000 miles now and I'm still getting better and smoother power from my ancient injectors. I can only imagine what it'd be like with newl freshened injectors.

Of course, trying something so radical (even though it's only 0.15% concentration) isn't for the faint of heart. :D

[KTA-Cummins]

Of course PEAK power is made at stoichiometric ratios of air and fuel. In a diesel they are designed "old school" based on a smoke limit,(now days they are designed based off NOX limits mostly) which is actually usually 20%less than peak power conditions. What this means is that any diesel at peak power conditions will smoke, at least to some exten. Peak power in a diesel is usually had with a heavy haze of smoke

[COMP461]

Welcome Brian, you are trully one of the inovators in the diesel world, glade to see you back in the public forum, now if we can get John Russin to get out and add words of wisdom thanks for you and Johns help with my past projects , with out you it would have taken longer .

with that ,I disigree with you on smoke, the reasion that you have to have a haze is with low pressure injectors and less then opitimal bowl and tip design I watched Project X make some increadable power with no smoke, and there is more power where that came from , but I'm being consertive with a 217,000 motor. I also think that higher rail pressure is another answer, along with fuel additive I'll write more when I'm not doing it with out the aid of my word processor

[Burner]

So how much of this {C12 H26} is broken down? Should the fuel be heated before it hits the rails or is this occurring at the tip? ......stupid here, Ionic or covalent bond trying to be broken here?

[Burner]

Ttt

[Cummins Express]

nice to see you back Brian

[hippie]

So how much of this {C12 H26} is broken down? Should the fuel be heated before it hits the rails or is this occurring at the tip? ......stupid here, Ionic or covalent bond trying to be broken here?

I'll jump in. If I'm wrong, I'm sure someone will correct me.

Fuel temp around 75F and charge air temp around 120F yields the best power. Injection pressures above 25K PSI provide better atomization of fuel. Better atomization of fuel leads to quicker evaporation of the liquid fuel. The faster it evaporates, the sooner it burns. If it burns sooner, less injection timing is needed.

Now, once the cylinder gasses start to burn, pressure and temperature rise rapidly. This condition leads to molecular separation and recombination. (The Fischer-Tropf process used to synthesize fuel exploits this condition.) Some of the recombination results in NOx and CO when temperature/pressure conditions are just right. Much of the recombination results in the generation of H2O and CO2 and a lot of heat.

Now if you don't care about 'pollutant' emissions, then you would want to time fuel injection to relatively maximize cylinder pressure from just after TDC and keep it near that maximum until the crank is down to around 90 deg. after TDC. If you care about emissions, you'll want to control injection so that maximum cylinder pressure is less than that needed to produce NOx. Common rail technology will shine here, since fuel flow can be controlled electronically.

Since diesel fuel is injected for a period of time after TDC, you also need to ensure that injection pressure is high enough to achieve good atomization even when cylinder pressure is up around 8000-10,000 PSI. Again, common rail technology will shine here, since it can create much higher injection pressures than ordinary mechanical systems can produce.

Current injection technology uses one injector nozzle per cylinder. The spray pattern from the nozzle is a best compromise between spraying when the piston is at TDC, and when the piston is lower. Two nozzles per cylinder might be better. Use one when the piston is near TDC and the spray needs to be nearly horizontal, and the other when the piston is lower and the spray can be more vertical. Perhaps some clever engineer will design a coaxial injector, where the outer solenoid opens near TDC to spray horizontally, and the inner solenoid opens when the cylinder is lower to spray more vertically. Or perhaps design an injector such that when opened slightly, fuel is directed to the smaller, horizontal holes; when opened moderately, fuel is directed to both horizontal and vertical holes, and when fully open, fuel is directed to the larger, vertical holes.

Of course, alternate fuels won't hurt either. Use GTL fuel (synthesized from natural gas). It contains no sulphur. It has much greater molecular uniformity, excellent lubricity and cetane rating of 70 or better. It might even work better at high RPM (greater than 6000). And I don't see why 87 octane pump gasoline or ethanol or methanol couldn't be used in a common rail compression ignition engine (while using lubricity enhancers, of course); if the charge air is hot enough to ignite diesel fuel, it should be hot enough to ignite alcohol or gasoline.

In summary, heat the fuel to the optimal temperature. Cool the charge air to the optimal temperature. Precisely control fuel injection so as to achieve and maintain optimal (or maximal, as desired) cylinder pressure. Redesign electronic injectors to employ more than one spray pattern. Use alternate fuels that evaporate and burn better.

Once you have a fuel control system that will produce the best and cleanest power, then move on to optimizing the mechanical system to minimize charge air and exhaust flow inefficiencies.

Of course, none of this will happen until computer geeks turn into dieselheads. It is a rare gearhead indeed who can program a controller.

[joefarmer]

Of course, none of this will happen until computer geeks turn into dieselheads. It is a rare gearhead indeed who can program a controller.

EFILive?

http://www.photopia.tyo.ca/photos/sacha-chua-the-geek-shall-inherit-the-earth.jpg

[Burner]

yeah, that's a start.......... but does EFI make anything for a Dodge/Cummins?


Also: Do you think it's possible that ONE injector can be split two-ways?

[Burner]

[quote=hippie]
Of course, alternate fuels won't hurt either. Use GTL fuel (synthesized from natural gas). It contains no sulphur. It has much greater molecular uniformity, excellent lubricity and cetane rating of 70 or better. It might even work better at high RPM (greater than 6000). And I don't see why 87 octane pump gasoline or ethanol or methanol couldn't be used in a common rail compression ignition engine (while using lubricity enhancers, of course); if the charge air is hot enough to ignite diesel fuel, it should be hot enough to ignite alcohol or gasoline.

In summary, heat the fuel to the optimal temperature. Cool the charge air to the optimal temperature. Precisely control fuel injection so as to achieve and maintain optimal (or maximal, as desired) cylinder pressure. Redesign electronic injectors to employ more than one spray pattern. Use alternate fuels that evaporate and burn better.

quote]


So, you're saying we need to crack the fuel? Or, the numbers need to be moved around a bit like C10, H18 or something even lower?


......I still don't understand why we here in the US don't just cut Diesel and have 20% Bio. 144,000 BTU's Vs~ 135,000 BTU's? Just guessing here.


Without beaking out the S&P orbital chart, what electron are we trying to capture? It would be far more easy and better for everyone if the fuel were changed for the better. Heck, if they could just find a better way to remove the sulfur without removing the lubricity.:doh:

[Noreaster]

I believe that the Common Rail injection will be a strong contender in the future if the control systems can be manipulated directly. P-pumps make big hp because of the massive quantity of fuel they can supply, but in most high hp applications there is a decrease in pressure with larger lines to increase volume at high RPM levels. I believe that a single modified CP3 with increased gear speed will dominate in the near future, this coupled with complete engine control and larger rails would allow for large volume of fuel delivered without losing pressure. I am unsure if it will be possible to build a completely "clean" high hp diesel motor, but the new injection systems will help dramatically. It will take more research into a better fuel to get the motors at this level to burn more efficiently. Maybe adding an agent equivalent to acetone such as stated earlier, coupled with a lubricity agent and cetane booster would would lighten the molecular bond of the fuel to allow for quicker more complete atomization of the fuel.

Wrong, increased gear speed is the easy way to get more fuel flowing but the pump will not last long. It is not designed for that, its a disaster waiting to happen.

[Burner]

.....So, can you run a compounded fuel system, like a triplex pump?

[Timbeaux]

The 2001 truck I am experimenting with is seeing a solid 2mpg increase, and it seems to run smoother and idle quieter than before. Also it is 22*'s here in Iowa this morning, and with the truck idling I noticed it smelled a lot like a 12v with about 17-19*'s of timing advance.

Do tell...... I'd like to gain 2 MPG :woohoo:

[jponder]

Do tell...... I'd like to gain 2 MPG :woohoo:

I can get you 2 etra MPG Tim.... Heck I can get you 6 if you want

[Burner]

I can get you 2 etra MPG Tim.... Heck I can get you 6 if you want


..........that "etra" just an't possible Ponder, not possible.

[jponder]

Branching effects the fuel also

Octane and 1,3,5 trimethyl pentane are both C8H18 but look very differently and I think the higher branched alkane burns better.

[Burner]

Great, now we REALLY need fps burn and btu's. :doh:

I had to look this up...... Diesel fuel ranges --->C10H22 to C15H32

[jponder]

Great, now we REALLY need fps burn and btu's. :doh:

I had to look this up...... Diesel fuel ranges --->C10H22 to C15H32

Makes sense as your alkane chain grows longer you start getting into waxes and diesel has a temp point where it starts to solidify into wax/parrafin.

For that matter why not use gas in a diesel as long as you put lubricant in it? Would gas with 2 stroke oil in it work?

[hippie]

EFILive? ...

Nope. I think tweaking EFI Live is done mostly by altering parameters. That is very different from writing the real-time software that makes the controller work in the first place.

If people like McRat are actually writing software, compiling it, linking it, and flashing the new binary onto the controller, I will stand corrected.

[hippie]

... Do you think it's possible that ONE injector can be split two-ways?

Certainly. It's only a mechanical device. Can it be made to operate reliably in the long term? There-in lies the rub, the long hours of hard work, and the hefty price for low-quantity manufacturing runs. :) It would probably be easier to produce a hybrid 24V head for the Cummins that has both internal and external injectors.

[Burner]

I wonder if Marine Diesel is thicker than #2? Ponder, ya got a chain on that?

[jponder]

Dont they have all kinds of heavy oils for marine like Bunker C

I say take Ethane C2H6 knock of 4 Hydrogens and make C2H2 IUPAC name Ethyne, common name Acetelyne. Screw that sissy butane injection run some acetylene in with maybe 40% oxygen. i bet you could hit 40 mpg at 50 mph

[Burner]

Oh my...... you want to melt the engine? And your emmssions, a little out of kilter. LOL

[jponder]

Oh my...... you want to melt the engine? And your emmssions, a little out of kilter. LOL

Heat is the thing right? Whole reason that piston is forced down is heat expanding the gas. You can make more pressure in the combustion chamber by more heat or you can ram more air in by making it colder, ie Nitrous. You have limits in that there is only so much pressure you can make and so much heat before stuff starts melting

[Burner]

So, if we look at something closer to Kerosene we could chop more of the smoke and have a slightly faster burn rate. (The fuel BTU would drop but I do not think it would matter because most all of the fuel would be surrounded with Oxygen and ignite.) Kerosene has a lower vapor point/flash point, ect.

The pressure should be a little better thoughout the combustion process, right? :confused:




Then again, might just want to raise the injection pressure to 40+ psi and MAKE the Diesel fuel shatter on the event.

[Billysgoat]

Certainly. It's only a mechanical device. Can it be made to operate reliably in the long term? There-in lies the rub, the long hours of hard work, and the hefty price for low-quantity manufacturing runs. :) It would probably be easier to produce a hybrid 24V head for the Cummins that has both internal and external injectors.

It's along those lines that I am thinking, maybe a "hemi" styled head with the injectors coming in at angles with specifically cut tips to make the spray pattern go where you want it?

[Burner]

or make it kind'a like an old 2-Stroke with an injector waayyy down low. Dang, that sure would make for some funky pistons.




I wonder if the Wankel motor would work with this fuel?

[Noreaster]

I wonder if Marine Diesel is thicker than #2? Ponder, ya got a chain on that?

Here marine diesel is offroad/home heating oil, comes from the same place & gets deliver by the same truck.

[Burner]

:eek: Holly snaps that's thick! C20 H42.......dang. I wonder if they do that for fire protection or because the motors are just that huge?

[turbothom]

You folks have gotten so technical, I ain't got a clue what the hell you saying.

[Burner]

Does anyone know the expected cetane rating of the new 15PPM Ultra Low Sulfur Diesel Fuel? Still testing, but I need to go one step farther with this.


I think it's 40..... but don't hold me to it. A little lower than what we "were" running. :(

[Burner]

Heat is the thing right? Whole reason that piston is forced down is heat expanding the gas. You can make more pressure in the combustion chamber by more heat or you can ram more air in by making it colder, ie Nitrous. You have limits in that there is only so much pressure you can make and so much heat before stuff starts melting

Hey, you know I'm pull'n you're legg Mr. Painthours. LOL

[Burner]

So you would need to raise the cetane rating by 10 points to reach it's peak atomization level.


No, don't think so. Then again, you may be right? We need some REAL pencil pusher here to help us. :doh:

[super diesel]

The closer to crud oil you get, the higher the BTUs go. The BTUs make the power thus less fuel used to make a specific hp and you get better fuel milage too. Make it flow easier though (big problem with out cutting it serverly). Thiner is better in this case (a lower specific gravity). Injects for the high pressure CR systems need more flow with out compromising the atomization. There is a way to increase the flow with out decreasing the atomization from opening the holes to a larger dia or increasing the amount of holes (hole sizes get closer inside and from the inferno of cumbustion as well as the pressure from the fuel and the needle slaming down the tips can start cracking inside and break off). There is a solution though which is being worked on. As far as speeding up the CP3, you will wear it out much faster, plus you can also float the piston cups inside from to much speed in which get tiddly winked out of it. Been there done that. There is no replacement for the shear volume the twin pumps can put out compared to a single. 1 moded one will never keep up to 2 moded ones and they (2 moded ones) will never keep up to 3 moded ones when the time comes. The injects can be made to flow enough with the proper atomization. I'm all over that right now.

[Burner]

:lolly: Go Man ...........GO!

don't forget your eraser. ;)


The new fuel may crack a little better than what we have now and that could make a world of difference.

[Rods]

What about usen a little bit of Nitro fuel from the R/C world , say like 10% nitro mixed , i dont know all the additives in it but its pretty oily , the engine works like a diesel usen the old glow plug to fire then combustion to keep it running , i was wondering if the nitro would blend with the diesel , i know some R/C cars have run on BIO

[Burner]

Good point........ how about cost?

[joefarmer]

RC fuel is only 45 or so a gallon. That's not too bad... LOL

brandon.

[Rods]

10% is about 20+ around here a gallon but if a few ounces help then on the track it might not b too bad , shoot i might try a little to c

[RacinDuallie]

Would it counter act with the already in place lubricants in the ULSD?

[Burner]

........as for the track (yes, flame suit on) I think that the "racing fuel" should come out of ONE tank and not BYOD.:stab:

[hippie]

It isn't the molecular bonds you have to break. You have to interfere with the surface tension of the fuel droplets to get the fuel to evaporate quicker; the faster it evaporates, the faster it burns. 2 ounces of acetone per 10 gallons (1280 oz.) of fuel seems to do this quite nicely. 5,000 miles now and I'm still getting better and smoother power from my ancient injectors. I can only imagine what it'd be like with newl freshened injectors.

Of course, trying something so radical (even though it's only 0.15% concentration) isn't for the faint of heart. :D

Another 1,000 miles and no fuel system failures as yet. I've gone through at least 3 quarts of acetone.

One thing I've noticed is that the 'smoothness' of the engine isn't consistent. I don't know if this is from the injectors falling further out of spec, or if acetone interacts with ULSD differently. Hauling the DHRA trailer from IN to TX, to MN and back to IN, the engine would sometimes purr real smooth, and sometime it would be its ratty-sounding old self. And this week hauling a UHaul from VA to South Bend and back, it kind-of did the same thing.

Unloaded, I'll typically run 300 miles to 1/2 on the fuel gauge, which is around 18.5 MPG. With acetone, I can get an extra 30 miles or so. Laden, I get 260-300 miles with acetone. But with ULSD and laden, I'm lucky to reach 250 miles to 1/2 tank. And it seems to smoke more.

Methinks I need to freshen the injectors before continuing my acetone research.

N

[Burner]

run some bio and clean out the system.......high %

[hippie]

The ideal cetane rating for diesel fuel is 50, anything higher does not add to the BTU content or have any real beneficial characteristics. So if the new fuel has a cetane rating of 40, then you would need to increase the rating by 10 points to make it most beneficial. So using Alkyl Nitrates and Di-tert-butyl Peroxides in the correct percentages will raise the cetane rating to the desired level. This coupled with fuel conditioners and small percentages of Propanone will allow the fuel to have a lighter density, lower flash point, and still retain the characteristics of high quality diesel fuel ie: lubricity and cetane rating. I am striving to become a novice pencil pusher as we speak.

So, ideal cetane is 50. What are the operating characteristics of the diesel engine for that cetane (RPM, injection timing, et al)? I thought cetane was a measure of the ignitability of the fuel. For most 'ordinary' diesel engines, I would expect 50 cetane would work real well. But what about a diesel engine running 6000-8000 RPM (or more)? Wouldn't the fuel need to be much more ignitable to get decent power at those speeds without needing 90 degree injection timing?