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two stroke, spark ignition diesel?
by
Dr. Diesel
on 01 Jul, 2008 13:01
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I went to cut the lawn the other day, and much to my chagrin there was only about 1/5th of a tank of gas remaining in my early '80's lawnboy two stroke mower. Further irritating, was the fact that the jerry can was empty too. I didn't feel like going to get gas, and it was my last opportunity to cut the lawn for another 5 days. Laziness set in, and I mixed 32:1 two stoke oil to Jet A1. (kerosene, mostly!) This went in with the 1/5th tank of gas and it fired right up. With half a turn on the mixture screw, it settled into a nice, lightly smoking two stroke buzz. I did both the front and rear yards and was pleased to note that it actually seemed to use less fuel on this mix than straight gas/oil!
I wonder if the same thing could be done with biodiesel in other gas engine equipment, and to what ratio?
I suppose that there's just enough gas in the mix to light it all off. I'll try straight kerosene/oil mix when this tank runs out to verify that idea.
I picked this lawnmower up at a junkyard for $20 and it's run flawlessly for two years. Beautiful.
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#1
by
zukgod1
on 01 Jul, 2008 14:13
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This sounds cool..
I have an 18hp rider, I would love to play as well.
Let us know what you come up with and I'll give it a try also.
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#2
by
jimfoo
on 01 Jul, 2008 15:15
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Once when almost out of gas at home, maybe 1 gal gas in the tank at most, I put about a gallon of diesel in my car and it drove just fine to the gas station. I tried this another time, but with a much higher ratio, and it died about halfway there amid huge clouds of smoke. Kerosene is probably better, but there is a limit. Gas is cheaper anyway.
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#3
by
burn_your_money
on 01 Jul, 2008 16:44
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My brother mixed some biodiesel 40:1 (1 part bio) and ran it in his chevette. He said the car seemed to run smoother.
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#4
by
burnt_servo
on 01 Jul, 2008 18:58
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over the last 15 years since i bought my gas powered air compressor , i've run alot of diesel through it , mainly since if was free or really cheap ....
it's just a 5 hp briggs ,
what i would do is start it on gas till it got to working temp , then while it was running , fill it up with diesel , then every hour or so , refill it with diesel . ( it would be running all day non stop ) , then run it almost out of diesel and add a bit of gas , the run it out of fuel .
if i didn't run gas through it and run it for 1/2 an hour or so , deposites from the diesel would build up on the intake valve stem causing it to stick open .
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#5
by
Dr. Diesel
on 01 Jul, 2008 20:25
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Interesting! This being jet fuel, is quite a bit more refined than diesel. I wonder if a 4 stroke would have similar intake valve buildups on kerosene? I thought maybe one could preheat the inlet air with muffler heat (on a 4 stroke... not so easy on the lawnboy) to help vaporize the kerosene.
Andrew, forums are fueled by people irrisistably adding their grandiloquent 2¢ worth. Nitpicking is part of my job, I'm used to it.
I guess this is why people call it 'dieseling' when a spark ignited engine runs on after the key's shut off!
Come to think of it, my lawnboy did continue to run roughly after i'd switched it's ignition off, until the emergency brake killed it. Hey! It IS a diesel!
Maybe I should up the compression and toss the spark plug in favor of a compression counter piston like diesel model airplanes have. Make her a true diesel. Would probably need a heat gun or ether to get it up to self-sustainable running temps though.
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#6
by
rabbitman
on 02 Jul, 2008 12:10
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What is a compression counter piston?
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#7
by
DonGTI
on 02 Jul, 2008 12:54
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in model engines instead of a sparkplug you get a metal slug that can be screwed in to increase compression and out to lessen it...
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#8
by
rabbitman
on 02 Jul, 2008 18:46
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in model engines instead of a sparkplug you get a metal slug that can be screwed in to increase compression and out to lessen it...
Weird, on both of my RC plane engines there's a glowplug that you put 1.5volts to, start it and then take the power off the GP and your good to go. Ones a 4-stroke and ones a 2-stroke.
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#9
by
Dr. Diesel
on 03 Jul, 2008 04:05
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yeah, and they run on glow fuel. but if you had a diesel engine, you'd have a little (usually) allen key on the top where the glowplug sits on a glow engine. Screw it in to increase compression, out to lessen. You can actually convert some sizes of O.S. (and clones) engines to run on diesel. I picked up the kit, but couldn't find a good source of liquid ether. the kit manufacturer suggested freezing then puncturing a can of quickstart with a brass nail to acquire ether. Scary...
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#10
by
Slave2School
on 03 Jul, 2008 14:37
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During the last great depression people ran much equipment on kero because at that time it was more available and cheaper. Usually a bit of modding required and you could only do it after teh vehicle was warmed up. Read the grapes of Wrath, I think it is mentioned in there
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#11
by
Quantum TD
on 03 Jul, 2008 16:39
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Read the grapes of Wrath, I think it is mentioned in there
See, us dieselknerds are worldly and edgymacated and such.
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#12
by
smoken u
on 09 Jul, 2008 10:09
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briggs and stratton made a semi-diesel engine, it ran on gasoline until it warmed up then you switched it to diesel.
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#13
by
Dr. Diesel
on 02 Sep, 2008 05:45
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Well after finally using up my 50/50 kerosene gasoline mix, I switched to straight kerosene (with 32:1 oil mix) It was just as hard to start as normal, (tuning problem I think, because it was the same on gasoline) and took a little longer to run steadily (she's on old girl, bought for $20 from the junkyard) but ran perfectly happily once all settled down.
I wonder if i'd have similar results on veggie oil? For that matter, would the oil mix be neccessary on veggie?
One note, after shutting off the ignition, continued to run in a lopey sort of way. I'd already shut the fuel off a minute earlier to clear the lines. So next time, i'll leave the fuel on and shut the ignition off only to see if it'll run on compression ignition alone!
Cool stuff!
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#14
by
jtanguay
on 02 Sep, 2008 19:36
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theres some old russian trucks that could be started on gas, and then switched over to diesel. pretty cool!
its a testament to the fact that diesels dont really need high compression.. just for cold starting :wink: