Hi fellas, impressed with your knowledge. This question has stumped near all `experts` on this side of the pond. I run a pushrod single supercharged on methanol. Nitrous injection is used, currently with petrol as supplementary fuel. I think diesel would be a much better choice for the supplement; higher calorific value, no detonation, gradual burn, and easily adjustable. People over here say it will detonate, or you can`t ignite with spark etc, the`ve already forgotten petrol/parafin tractors. Any advice as to why I shouldn`t try?

I'm going to arm chair this one. From the tractor pullers I know, they take a diesel engine and replace the head to run alcohol. Spark ginition....ect.

To use diesel you need to inject and compress....no spark. Most of the racing engines used in cars on alcohol have an 18:1 compression. The start point for alcohol is a compression of 13.5:1

Diesel compression rates start at 16:1 up to 25:1

So to add diesel your lowest compression would be 16:1 on a start point the meth will burn faster than diesel so you would have to time the fuel to inject with your meth.

Not sure if anything I said helps...........If your wanting to switch to diesel you would have to replace the head

Thanks Max, the motor is supercharged on methanol, the idea is to gear her tall and inject nitrous to pull her up through the revs, thus accelerating the back wheel, this after the launch so the wheel is turning and the hard work done. It is the fuel to inject with the nitrous, petrol leads to high temperatures and detonation risk, I would like to try diesel with the nitrous, into the spark ignited methanol. Revs for power from 5-7000 so not too fast. The nitrous and diesel would spray into the port so the ignition would be by spark, not compression, the diesel can be spark ignited `cos my workshop heater is, in fact the Royal Navys` gas turbines are diesel spark ignited. The question appears to be juggling the various flame rates: compressed methanol is slow, nitrous speeds things up, diesel would slow it. I`m aiming for a longer push on the piston rather than the hammer blow of say sparked gas, without detonation or too much heat. A fella from Oz said don`t do it as it would savagely detonate but I don`t think this is so, as I said so-called experts over here are not even sure how diesel ignites, some say mild explosion, some say by flame front. Nearly all have been less than helpful so I`m asking over the pond!

I have always been under the impression that you couldnt increase your octane by just bumping up the octane of your enrichment side of your N2O, the main fuel coming from the carb or injtors would still let go when ever it normaly would. Why arnt you injecting meth with your enrichment side of your n2o? I would guess that the diesel wouldnt start to ignight till the meth lit it off and then depending on piston speed it may be burning latter than you want??? Maybe it would go off with the ign? Better have one bad assed ign box though. One way to find out I suppose since I have no idea and am just pulling stuff out my rear

Thanks Ratlover, the anti detonant value from methanol is very high, unless it gets hot. The nitrous cools the charge so detonation isn`t a problem. Some folks say that a methanol motor with nitrous and methanol injection actually cools too much and the predicted increase in power is not seen, but nitrous and gas brings the temp up and very good increase can be seen. But you walk back to running a detonation problem, which is where I thought try diesel. Your point of the slow combustion of diesel may be the telling one as to it working, at the moment I need reassurance that it won`t blow up first time, as the Aussie warned.

Sounds like you need to meet an aquaintence of mine named Lab RAT http://www.dieselplace.com/forum/search.php?searchid=241571 j/k

Well I know numerous guys running just alky and **** tons of spray and an air squasher that run pretty hard at the track.

From what I've been told you can mix fuels in a tank and it will take on properties of both but when you inject em seperate you are basicly dealing with 2 clouds of fuel doing thier own thing.

I know propane is used in some applications to enrich the n2o.

Seems there`s an understandable reluctance to wet the toes on this one so I`ll ask if nitrous injection on your trucks shortens flame travel, notably increases revs, or just gives more power without revving up. And in what way does it all go wrong? Is there a detonation destruction? I don`t mean blow-ups when the revs are too low.

In gass, diesel, what ever......With n2o you will pick up power so it will pull harder and rev quicker. It shouldnt rev higher. That is if the rest of the drive train is up to it. With a converter it will flash higher on you, just blow through it possibly, ect.

ok, crash corse time. Diesel is vastly different from an ign motor in that a diesel cant go to lean.....well you can but not like a gasser. A diesel acts completly different from a gasser in how it operates. In a diesel its fual air ratio is CONSTANTLY changing and varys, a gasser you want it pretty constant. A diesel runs with no throttle blades like a carbs butterflies on a gasser. If you want to increase the revs of a diesel instead of opening the blades a bit more so air can be sucked in and you try to mix the proper amont of fuel with it for the bang on a diesel you just add more fuel and the air gets drawn in with it. Diesels use a dry shot with NO extra enrichment like on a gasser. What we do is just spray a bunch of N2O into our motor. If we spray too much we can put out the flame so to speak in an extreme case or in a non extreme case it just stops making power. Make sense? Detonation is just combustion when you dont want it. Adding more air dosnt really change when the bang happens in a diesel becasue if you add too much it cools down on you. Also fuel and air arnt being drawn into the cylinder in a diesel, the fuel is injected in there at a high pressure(I know there are some grey areas but for simplicity).

On a gasser when you go lean you start creating heat, heat casues the bang to happen before it should, bang happening before it should is what blows things the heck up. On a gasser you adjust your timing by altering when the spark goes off, in a diesel you alter the timing by when the fuel is injected.

See the basic differences?

People make plenty of power with just meth and N2O.

Attaboy, why can`t they explain like that over here? Like the definition of det! You can indeed make plenty of power with nos and dope, I do, Iwant to make more. Supercharging singles well is not an easy art, nitro is uncontrollable in as much as you have to have it on the line and treat it with respect, nos has theoretical safe power increases that people are not yet finding, but if you don`t push the envelope you`re largely wasting your time on this planet. Thanks, I`ll try with diesel enrichment, and if that don`t work I`ll try parafin which shoiuld have a faster burn.

Please report back! This is some interesting stuff. Good luck in pushing the envelope!:)

If I were you, I'd experiment with propane as a supplement for nitrous. It is getting more and more common with the gasoline crowd as it is more detonation resistant and easier to configure than gasoline. It does not puddle in the intake tract and is far safer on both the engine and the fire crew.

Diesel? Takes big pressure/temp to vaporize/atomize diesel.

Lookie there, someone chiming in that isnt cluless like me):h

I'm telling ya, do some looking into our buddy lab rat;) ):h

Hey Ratlover , no joy with your ref, any other route to LabRat?

Sorry McRat, didn`t see we are on page 2 now so just seen your post. Have read the sites` other propane stuff but didn`t know the gassers were using it as a suoolement. You don`t have a lead I can chase?

Attaboy, why can`t they explain like that over here? Like the definition of det! You can indeed make plenty of power with nos and dope, I do, Iwant to make more. Supercharging singles well is not an easy art, nitro is uncontrollable in as much as you have to have it on the line and treat it with respect, nos has theoretical safe power increases that people are not yet finding, but if you don`t push the envelope you`re largely wasting your time on this planet. Thanks, I`ll try with diesel enrichment, and if that don`t work I`ll try parafin which shoiuld have a faster burn.

Why can't you start off by mixing some diesel in w/ gas and as things go bump up the %.

Sorry, the Lab RAT is kinda a joke http://www.dieselplace.com/forum/showthread.php?t=14582