LT_HOGWEED

would a nitro engine run on diesel has any one tryed this

blw

My Feedback: (3)

Here is the diesel forum:

http://www.rcuniverse.com/forum/forumid_87/tt.htm

Motorboy

Or go to the web site and there are the cylinder head adapted for your engine if you want to convert the engine to a diesel engine: http://www.davisdieseldevelopment.com/ [sm=thumbs_up.gif][sm=shades_smile.gif]

Lnewqban

Only by removing the glow plug and installing a variable volume combustion chamber.
.........and using different fuel, of course.

Yes, many people has tried it before,..........and have suceeded.
Follow the above links.

Sport_Pilot

If it did it wouldn't be a nitro engine. Not that it was to begin with.

MJD

My Feedback: (1)

The simple answer is yes, a glow engine can be run on diesel with a conversion head, and conversions have been popular for a few decades. Some handle the increased load on the mechanicals better than others (higher cylinder pressure, increased abuse on connecting rod, crankpin, crank, etc.).

Jim Thomerson

You can also run a glow engine on model diesel fuel as is, but a lot of folks will explain why you can't.

Scar

My Feedback: (3)

I didn't see anyone who responded in the affirmative mention the actual fuel used. (Forgive me if I missed one.)

Diesel conversions don't use diesel fuel alone. Model diesel fuel is a mixture of diesel fuel and ether.

Good luck,
Dave Olson

NM2K

My Feedback: (14)

Model Diesel fuel, which is the only fuel that will work in a model Diesel engine, is not the Diesel fuel that 18 wheelers burn. It is completely different. Model Diesel fuel costs roughly twice as much as model glow fuel, but you only burn half as much. So there really isn't any savings to be realized by switching fuel types.


Ed Cregger

earlwb

Actually as Jim Tomerson mentioned, if you use model diesel fuel, many glow engines will actually run off of it. The trick is whether the fixed compression ratio will work Ok for your application or not. The variable compression diesel heads had the advantage of letting you change the compression ratio which had the effect of advancing or retarding the ignition timing, so you could run different propellers. With a fixed compression ratio you are limited as to what props you can run.

LT_HOGWEED

wow lots of good info .i have been looking around the web does not seem to hard to do with some help of course may be easer go get a bigger engine

NM2K

My Feedback: (14)

Yes, earlwb, I own an old fixed compression ratio Deezil and I have ran a few Enya four-strokes on model Diesel fuel before. I am familiar with changing the prop load on the engine to match the compression/etc.


Ed Cregger

DarZeelon

Quote:

ORIGINAL: LT_HOGWEED

Would a nitro engine run on Diesel? Has any one tried this?

HogWeed,


Not 'nitro engine' - It's a glow engine and I don't care how many mistakenly call it that, because they just don't know better...

And no, it will not. Diesel (automotive type) is just not volatile enough.
It would not sustain the plug's glow either, because unlike methanol, its vapors cannot catalise on the platinum and would not make it glow.

In two words - 'Forget it!'

Hobbsy

My Feedback: (102)

increased abuse on connecting rod, crankpin, crank, etc.). (partial quote)



I must disagree with this part of your post. Abuse only occurs when the operator sets the compression too high. Compression must be reduced as you increase the load. Diesel conversions and purpose built Diesel use about 50% less fuel than their glow counterparts. Mr. Davis recommends a 50% prop load increase. I do it many times by simply using a three blade prop of the same size.

earlwb

One other thought, is a diesel engine that runs on regular diesel fuel that the trucks and cars use, has a finite limit on how small of a displacement engine you can go.  I do not remember anyone building a diesel engine of less than 50cc displacement to run on regular diesel fuel. They have manfuactured some scooters and motorcycles for Asian area consumption with 50cc diesel engines. But a major problem is the engines themselves are quite robust and very heavy.

The problem you have is as the engine gets smaller and smaller it gets to where it cannot compress the diesel fuel enough to get it hot enough to ignite. As well as being able to maintain engine heat without cooling off too much. The second problem is using fuel injection with fuel injectors, you have a minimum limit on how small you can make an injector and still have high fuel pressure to get it to work Ok. Air molecules and atoms stay the same size as the engine gets smaller, same with diesel fuel, the atoms and molecules don't shrink as the engine gets smaller.

Which is why they came with with ether, kerosene and castor oil as the classic model diesel engine fuel.

Motorboy

For home brewer of dieselfuel, the kerosene can be replaced with lamp oil, auto diesel from pump at gas station, white spirit (paintbrush cleaner), the castor oil can be replaced with 10w-40 or 15W-50 motoroil. It is depending on where you live which of these are availabe to mix own diesel fuel.

The diesel engine can run without ether if compression are good enough to ignite the etherless fuel, see the movie of my engine are running without ether :

[youtube]http://www.youtube.com/watch?v=wmH6WUMUEJg[/youtube]

earlwb

I know of guys doing this before, but they had used ether in the fuel to get the engine started and then after the engine had heated up good, they switched over to their etherless blend.

downunder

A true diesel works by always compressing the maximum possible amount of air at all times which means there's no throttle in the inlet manifold. This is done so the temperature of the compressed air can be as high as possible. The power is then regulated by injecting a measured volume of fuel into the hot gas which is above the ignition point of the fuel mist. I remember when this subject came up once before, someone mentioned the possibility of using ink jet printer nozzles for a fuel injection system. That could just possibly work .

Motorboy

Some engine are started up with ether and some without ether.. My engine in movie was started up without ether.

earlwb

How well did your engine run?  some others that ran straight diesel or kerosene had problems where the engine wasn't burning all the fuel and there was a large power loss too.

Motorboy

My engine ran at 66% kerosene, really no difference between model diesel engine fuel (with ether) and pure kerosene when i ran the engine. My engine are a long stroke engine and are not a fast running engine as a modern diesel engine. The engine are 3.05 ccm volume, stroke 3/4", bore 9/16" long stroke engine with 12.5x6 propeller, 4600 rpm.

To run the engine, it must be less leakage between cylinder/piston to make air hot enough to ignite the kerosene and the fuel must be well atomized to be easy to ignite to example smaller carburator or well designed transfer canal to make gas velocity high enoug to make fuel atomized. In the smaller engine are more difficult to start the engine without ether. I tried with a 0.8 cc PAW engine, never got ignited a drop of kerosene cause too small heat of compression.

DarZeelon

Jens,


While you are a master of designing and building engines, this Diesel is not what I would call a paragon of power.

4,600 RPM with a 12.5x6 prop (I used APC's constant of 1.23) calculates to only 0.095 HP.
A muffler-equipped glow engine of such displacement, makes about 0.47 HP (real; not manufacturer's rated) - roughly 5 times more power.

NM2K

My Feedback: (14)

I hope not to offend anyone, but any model powering engine that won't throttle is totally useless to me. Lots of things can be made to happen when an engine is only going to be expected to run at one speed. Not so when variable throttling is tossed into the equation.


Ed Cregger

Motorboy

The engine was builded after the plan from 1947 hence the engine in this period was not hi reving engine, the solvent are bigger propeller and low pitch to make better thrust in low rpm when the engines had long stroke and small carburator and the timing are difference from modern engines with better timing, shorter stroke and bigger carburator.

NM2K

My Feedback: (14)

You do beautiful work, Jens.


Ed Cregger