diesel race saw

[husky hustler]

a gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 all the way up to 25:1. The compression might be a problem, however ratio should be close enough that a simple adjustment could overcome it. Below are the explosive ranges in which these fuels have to be in to make combustion possible.

Diesel
Lower Exp Limit: 1.3% (NTP, 1992)
Upper Exp Limit: 6.0% (NTP, 1992)

Gasoline
Lower Exp Limit: 1.4% (USCG, 1999)
Upper Exp Limit: 7.4% (USCG, 1999)

As you can see, there isn't a great difference in the explosive range. Injection, and compression are going to be our problem. opcorn: opcorn: opcorn:

 

[Crofter]

Husky Hustler; are the explosive limits relative to ambient pressure and temperature?
I think that some of the occasions of hearing about gasoline engines starting and running even half athed well were actually burning only a diluted gas and diesel mixture. The old universal fueled engines did it well but they had special provisions.

 

[Al Smith]

If I'm not mistaken diesel fuel uses a cetane rating rather than octane.

The old D model John Deeres only had about 41/2 to 1 comp ratio.They were however over 500 cubic inch,two cylinders.The very early ones were equipted with water injection as the kerosine was not the best in the twentys as is later became.You open the water valve just enough to stop the engine from pinging under load,while in operation.The orginal HP rating was 15 drawbar,27 belt at about 800 rpm.Start on gas,ran on distallate[kerosine] Extremely fast road speed,about 4 miles per hour ,they were made to replace a team of horses,ya know.

That was spark ingition.True diesel needs a much higher comp ratio to operate.

 

[husky hustler]

The explosive limits should be true despite compression. If there is not enough fuel it won't ignite. If there is too much fuel, it won't ignite. Compression should only make the ignition more violent greenchainsaw: ) That is why when a saw looses compression you might see smoke when you try to start it, but there isn't any bang.

 

[husky hustler]

The explosive limits should be true despite compression. If there is not enough fuel it won't ignite. If there is too much fuel, it won't ignite. Compression should only make the ignition more violent greenchainsaw: ) That is why when a saw looses compression you might see smoke when you try to start it, but there isn't any bang.

 

[drmiller100]

again,

so how are you going to get the diesel to evaporate or atomize through a carburetor???

 

[joesawer]

again,

so how are you going to get the diesel to evaporate or atomize through a carburetor???

The fuel does not evaporate or atomize or do any other mystical thing in the carb of a multi fuel engine. All it has to do is be in small enough droplets to stay suspended in a high velocity air stream to make it to the combustion chamber (that was pre heated with gas). The heat in the combustion chamber evaporates it enough to burn.

 

[Al Smith]

again,

so how are you going to get the diesel to evaporate or atomize through a carburetor???

Are you talking about the fuel or the engine design?

Don't get a glow engine and diesel confused.They are not one in the same.

Now then,on the old multi fuel tractors the manifold was specially built to capture heat which vaporized the kerosine.I don't know if you could get #2 diesel fuel to run in those things or not,never tried it.To run right ,you needed to keep the water temp at about 190 degrees .Below about 170 they started to hiccup .The radiators had shutters you could open or close to regulate the temp.

On the huge marine diesels they heat the fuel before it ever gets injected into the engine.Those humongus things burn bunker c oil.Which is black gooey stuff that contains a huge amount of btu's but extreme measures must be used to extract all that latent power.By the same token ships that use a conventional high pressure boiler start them on number 2 oil then switch to bunker c after every thing has warmed up.

 

[husky hustler]

The fuel does not evaporate or atomize or do any other mystical thing in the carb of a multi fuel engine. All it has to do is be in small enough droplets to stay suspended in a high velocity air stream to make it to the combustion chamber (that was pre heated with gas). The heat in the combustion chamber evaporates it enough to burn.

Correct! Surface area is all that is required of the fuel, just on a much more molecular level. as long as the fuel is "sprayed" in a mist with the correct ratio of air, you will have ignition.

 

[(WLL)]

diesel saws

how good would a diesel powered chainsaw mill work? better or worse? with a hand held saw i like lite, and i never herd of a lite diesel. there is small single cylinder diesel engines used in atv's and small equipment like a bomag roller. what about a full nitro-methane race saw? fast, lite,and expensive. i herd long ago gas was used in diesel's in cold temps for anti-jel additive.i was also told diesel's work very similar to to strokes. true or not? I'm still waiting for a fuel injected stihl.

 

[husky hustler]

The intelicarb and 4mix technology are paving the way for fuel injection. I give it 10 years max.

 

[berryman70]

I've found this to be an interesting thread. My cousin Just moved back here (NY) from California, after not seeing him for over 30 years, He's a motorhead from way back, He's 60 years old now. In his younger days & I was just a little kid he had some radical go carts, twin macs & they would fly. We got to talking two stokes & he said he used to mix white gas (colman lantern fuel) & either in his pre-mix bean oil- castrol at 16:1 he couldn't remember the exact ratio of white gas & either he used. If I'm not mistaken white gas is a more refined Kerosine, probably the either was used to increase the flash point. Anybody ever heard of this? I think it's just another myth, BUT I know he had some very fast carts.

 

[husky394]

White gas is just un-leaded gasoline. Before catalytic converters, it was the only un-leaded commonly available besides Aamco It came in 55 gallon drums. My uncles inisited on using it in thier lawnmowers, fearing lead deposits on the valves.

 

[drmiller100]

very low octane unleaded.

from memory, 80????

 

[Crofter]

If you search it out, there was a thread on here 3 or 4 years ago about so called white gas. Not all the same thing. I believe there was a "marine white" that was not the same at all as the Coleman fuel. The coleman appliances would clog right up with leaded fuel whether it was dyed coloured or not. I remember mother useing a Coleman clothes iron!

 

[olyman]

thers a whole lot of misinformed--and smart mouth --people on this thread--and theres others--that have been there--done that--for those that dont know---go talk to a real old person about "distlliate" in old tractors---any make--they all had them--not just deere--and "distillate" was the reason for water injection--and if it was hot enough--i imagine #2 diesel would work also---dont care who dont like it---

 

[weimedog]

A gasoline engine will run trouble free on diesel if they are fully warmed and the compression is 5 1/2 to 1

Grampa

A few personal diesel/gas experiences..

1) I had an old Austin Westrn Road Grader with an International UD-14 Diesel 4 cylinder motor in the thing. You would start it on a gas system. had an ignition system , carburator, and a set of valves for the gas intake to work with..then when it was warm..you pull a lever to close the gasoline intake side and shut off the ignition..and allow the fuel injection pump for the DIESEL system to work. This was a OLD design and it worked REALLY well in very cold situations. I eventually replaced it with Detriot power..another story.

2) My internation W-4 has the Kerosine fuel option. It works. Start with gasoline and them open the valve from the Keroses tank and begine to bleed kero into the carb. It runs..not as much power and lots of blue smoke.

3) I was on a business trip for a few weeks. My nightly call to home was met with the problems of the day..my kids motorcycle mysteriously started running badly..as well as the lawn mower...mystery wasn't solved yet when I got home. AND I was able to get it started...and it would run but not really well. I noticed it just would not warm up! to the touch either. AND the plugs were wet..and then it dawned on me the smell was off. Could NOT kick startit but COULD BUMP start it!!.Sounded like the timing was off and wouldn't build RPM's..but IT RAN well enough to drag that kid around the yard! It was a Honda CR125 and it was running on Diesel/Gas (what ever was left in the tank) because they had run out of gas and it was in a FUEL can.....in the lawn mower and motorcycle. (Actually pre-mixed with BelRay 2-Stroke oil!)

4) A racing buddy of mine was in a real hurry to beat me home..we got to a gas station and I got to the "prefered" pump first ..he went to the only thing left...filled..realized it was Diesel and then the yelling started! SO we just fired up that truck and down the road he went..and it started smoking more an more but continued to run all the way home. (1980 something Chevy 350 with the higher performance options).

SO a hot gasolene engine might run with Diesel...just not well and probably a B**ch to start.

 

[user 19670]

Might be true

When I was a kid at the glencoe fair, i talked to a guy there racing, and he told me that his saw would run on diesel. He said that he would get it hot on gas and then could ????ch it over to diesel. Is there any truth to this ?

At our rural Fall Fairs around here there is a display by the "Tired Iron Club" of Kakabeka Falls Ontario, Canada. They specialize in antique stationary engines, generators, gas washing machines, etc. etc. One item I saw last fall was a dual fuel antique chainsaw that runs on gasoline and can be switched over to kerosene or diesel. Never saw it running though some of the other engines are running when the owner is present.
Engines from those days were slow running, long stroke torque monsters (unlike these days).

 

[timberwolf]

I'm sure it could be done, but does it make much sense?

1 weight is a big factor in a chainsaw.

2 diesels produce there power at lower RPM and higher torque.

3 For an engine to produce the same HP at Lower RPM it must produce higher torque numbers.

4 To produce higher torque numbers higher cylinder pressures or large engine dimentions are required.

5 Higher cylinder pressures produce more load on bearings, crank, rod, piston crown, and the components need to be built heavier to stand up to the extra load.

6 Diesel engines in general cc to cc produce lower hp numbers than gas.

7 Very fast saws not used for cutting fire wood need chainspeed to cut fast and work in the upper end of the powerband, diesels rev slow and produce peak power down lower in the powerband.

 

[1953greg]

When I was a kid at the glencoe fair, i talked to a guy there racing, and he told me that his saw would run on diesel. He said that he would get it hot on gas and then could ????ch it over to diesel. Is there any truth to this ?

i surely doubt it. but there is a lot i dont know

i think it was rubedog that told me a story bout someone that destroyed the lower end on 3 or 4 large stihl saws before it was discovered that the mix can had maybe a quart or so of leftover diesel where someone had used the mix can for fuel can.
maybe that as saws run on the edge anyhow and the added energy from the diesel is too much or some preignition going on.

only experience i have is my friend borrowed my f250 5.4l injected gas burner and was nice enough to fill it up with diesel before returning (he really is a great guy). 2/3 fuel 1/3 gas. siphoned the tank empty and refilled. no problem. but now what to do w/ 26gal of gas/fuel mix. talked to mechanic and he said just put couple gallons of the mix into each vechicle until used up (5-10% total diesel). no problem what so ever up to 10% diesel. so i experimented and started putting more n more in til problems occoured. @~15% hard starting when cold. ok hot. @~20% nearly impossible to start when cold. difficult when hot and smokes and pings a bunch.