Diesel chainsaw

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I want a chainsaw that sounds like my 7.3 Powerstroke and runs on veggie oil so my customers get hungry when the whole neighborhood smells like french fries. At about noon each day we can stick an extra sprocket on the saw to turn the rotisserie and hand out free hats with our logo to go along with sandwiches we sell the neighbors drawn in by the smell. It pure marketing genius I tell ya, and eco friendly. Course chances are I would get fatter :(
Dave
 
The main lubricant in Diesel fuel was sulfur. I say "was" because the EPA took almost all of it out a few years ago.
The newer engines are OK with it but older one is a question mark. I add one ounce of 2 cycle oil to a gallon to help lubricate my diesels.

I agree mostly, but I think the diesel in the US is to refined even for the newer engines. My wife has a VW TDI and the injection pumps have a much higher failure rate than in Europe - blamed on how dry out diesel is. I've run a lubricant/fuel improver since the first day to avoid that problem.

Some of the older engines actually fare quite well since many of their injection pumps are engine oil lubricated on one side, diesel fuel on the other (thinking the cummins P7100 here).

A chainsaw run on diesel might not need additional lubricant in the fuel, but I wouldn't be the bank on it.

Waylan
 
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new version

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Well, you don't have to worry about skeeters with that second one. :msp_scared:
 
As I recall, military saws ('both sides') in WWII were diesel (?), which makes sense, as they would run on the same fuel as their trucks

Well, now I can't find the reference which made me think of that.

The book "Chainsaws: A History" identifies the Comet as the first (production) diesel chainsaw, in 1949. They also refer to a Jonsereds model XA, which Acres site says ran on diesel, kerosene, or gasoline mixed with oil. Produced between 1954 and 1960.

Philbert
 
I agree mostly, but I think the diesel in the US is to refined even for the newer engines. My wife has a VW TDI and the injection pumps have a much higher failure rate than in Europe - blamed on how dry out diesel is. I've run a lubricant/fuel improver since the first day to avoid that problem.

Some of the older engines actually fare quite well since many of their injection pumps are engine oil lubricated on one side, diesel fuel on the other (thinking the cummins P7100 here).

A chainsaw run on diesel might not need additional lubricant in the fuel, but I wouldn't be the bank on it.

Waylan

Local truckstop here has biodiesel blend. I noticed a nice improvement in my truck running when I switched to it, as in, a whole gear I didn't have to downshift on some local hills. Pretty in your face improvement really. The biodiesel part is supposed to be pretty good lube at around 2% by volume, that is, not much is needed at all. It beat out a ton of aftermarket additives in some tests. Think this was at bobistheoilguy. Dumping in two stroke mix was good too, but just running a very small amount of the biodiesel was adequate to make up for lack of sulphur.

I don't like ethanol gas at all, but do like biodiesel blended diesel.
 
I ran a diesel Mercedes sedan for many years. It would go 0 to 60 in about 3 seconds if you pushed it out of a helicopter. Otherwise, the run took about 25-30 seconds with your foot flat on the board. Had a whopping 63hp at 3000rpm. Everything from the canister filter to changing the oil in the injector pump was a pain but it was a great car. Built like a tank.

Mitsubishi Fuso FG 4x4 is a great medium sized diesel truck. Been looking for one for a while but used they always want the moon and stars for them. A would also like a Unimog. Maybe if I win the powerball….

When I started driving my father had a 1961 Mercedes 190D, 4 speed on the column. I would do 0-60 in one mile or three days whichever came first. My jeep diesel is stronger then the 4 cly 2.5 but weaker then the 4.0 gas engines.

I have a 1986 Fuso but its not the 4x4. It does have the Chrysler 727 automatic in it. That would make a good swap in a dodge pickup.

Later
Dan
 
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It would be very interesting to see something like that. I'm a diesel mechanic and I would think it would have to be a whole different concept than what I'm used to. Without a computer controlled fuel system, turbo charging and aftercooling, I couldn't imagine it being any different than the saws in the videos. I also don't understand how the lubrication would work. The diesel fuel would burn as it is being injected. It ain't gonna hang around and lube stuff. It would need a crankcase, or oil reservoir with a pump. How's that gonna work with all position use. Starting it could be another issue. I know some old Cummins had a compression release back in the 60's or so, but that's even weird with a compression combustion engine. What about the Jake Brake?
 
I know this wont happen in the states again but I would love to have a modern diesel compact pickup truck. Oddly, I strongly prefer gas engines in tractors and machinery.
 
And all the saw manufacturers (that I am aware of) recommend 89 *or higher* octane to run their saws on. Not 87. So if you run premium, it is almost a wash at cost per gallon (I run premium no ethanol, 93 octane, yes, it cost a lot more than the cheapest E10 you can find around here...I don't care either). And some guys run avgas, at lots more per gallon.

Plus diesel would not need mix oil added to the cost.

right now, I get diesel at around 3.75 (that is road diesel, farm diesel would be cheaper), versus gallon of premium gasoline (again, no ethanol, they charge higher but I can get it locally so I use it) at 4 bucks and mix oil, call it around 75 cent a gallon, so $3.75 versus $4.75 cost per gallon to run in this theoretical new diesel saw. Diesel would win on cost per tank in other words.

Just sayin'.....

Dunno where you're getting that octane info. ALL the saws I've seen octane requirements for, including all but one of mine, specify 87. RedMax calls for 89, but GZ4000 was very happy with 87 as a test. 93 is plain silly.

If you're expecting diesel fuel to provide/include the lube properties you'd get from mix oil or injection oil for an air-cooled 2-stroke, lots of luck with that. Expect some funny noises, over the diesel-din. Funny how over-the-road diesels rely on crankcase filled with lube, and pressure-spray it from below on piston & bore. Rings on a diesel are VERY demanding on lube. Your "spreadsheet" better include obit info.
 
As neat as it would be, diesel prices are high. Performance would need to be spectacular for me to purchase one.

Yeah but I think you are over looking the fact that you would be able to run dyed off road diesel in a saw which is a good bit cheaper than on road diesel. Plus you could have a jake brake instead of a chain brake! :hmm3grin2orange:
 
Dunno where you're getting that octane info. ALL the saws I've seen octane requirements for, including all but one of mine, specify 87. RedMax calls for 89, but GZ4000 was very happy with 87 as a test. 93 is plain silly.

If you're expecting diesel fuel to provide/include the lube properties you'd get from mix oil or injection oil for an air-cooled 2-stroke, lots of luck with that. Expect some funny noises, over the diesel-din. Funny how over-the-road diesels rely on crankcase filled with lube, and pressure-spray it from below on piston & bore. Rings on a diesel are VERY demanding on lube. Your "spreadsheet" better include obit info.

Well, we will see how that prototype saw runs, if it needs additional mix oil or not.
 
Dunno where you're getting that octane info. ALL the saws I've seen octane requirements for, including all but one of mine, specify 87. RedMax calls for 89, but GZ4000 was very happy with 87 as a test. 93 is plain silly.
There is one factor that may have a bearing on that, particularly for the users of this forum in particular. The moment anyone modifies their saw and increases compression, the octane required also increases, so for a high compression saw, perhaps 93 is not as far out as it initially appears. Anyway too much octane is not as harmful as too little.

If you're expecting diesel fuel to provide/include the lube properties you'd get from mix oil or injection oil for an air-cooled 2-stroke, lots of luck with that. Expect some funny noises, over the diesel-din. Funny how over-the-road diesels rely on crankcase filled with lube, and pressure-spray it from below on piston & bore. Rings on a diesel are VERY demanding on lube. Your "spreadsheet" better include obit info.
Totally agree with that one.
It seems that many have overlooked the intrinsic differences between a diesel compression ignition engine, (even 2 stroke blower scavenged Detroit) and a petrol spark ignition engine. A petrol 2 stroke inducts the charge via the crankcase where it is then ignited by a high voltage spark at the correct timing. A diesel on the other hand inducts only air, which is then compressed, causing a rise in temperature of the charge. Diesel is then injected at the correct time, which combusts in contact with the hot air. Thus, no matter how well diesel lubricates, it never goes near the parts that need lubricating. Now if we use the example of a semi diesel such as the early "diesel" saws, we could induce the charge via the crankcase in traditional 2 stroke style. The downside is the fact that semi diesels are typically large displacement for their power and are not the most convenient to start.
We are now left with the prospect of a dry sump lubricated chainsaw with a mechanical injector pump and injector, (possibly a mechanical unit injector) which by necessity will have to be either 4 stroke or we could add a blower to scavenge the combustion gasses and run the 2 stroke cycle ala Detroit Diesel - still need camshaft and timing gears etc. Turbo charging optional. Conversely we could run an electronic injection system, (with a battery included) which all adds weight.
I love the diesel process, but I can't really see its application in small power equipment.
I am not convinced that the modern "diesel chainsaw" in the youtube clip was actually a diesel anyway, didn't sound right.
 
I started adding Marvel Mystery Oil or 2-stroke oil to my fuel for my 7.3 powerstroke. It didn't make a noticable difference to me, but it runs so darn good anyway so I can't complain.

A 2-stroke diesel depends on positive intake manifold pressure, the truck engines use a supercharger to force the air into the combustion chamber so they run.

Since diesel's rely on compression and injection of fuel at the right time for ignition a compression release won't work.

If you want a low-compression engine that runs multiple fuels including diesel you really are talking a "hot bulb" which was popular in the 19th century and is even more non-suited to chainsaw action.

I love diesel's but don't see the application for a saw outside of doing something cool for fun, they just don't have the horsepower/weight ratio or the RPM. You would need to run something like a 10 tooth rear sprocket to get reasonable chain speed as the general slow speed of diesels would probably limit the saw to less than 6000 rpm (total guess).
 
Totally agree with that one.
It seems that many have overlooked the intrinsic differences between a diesel compression ignition engine, (even 2 stroke blower scavenged Detroit) and a petrol spark ignition engine. A petrol 2 stroke inducts the charge via the crankcase where it is then ignited by a high voltage spark at the correct timing. A diesel on the other hand inducts only air, which is then compressed, causing a rise in temperature of the charge. Diesel is then injected at the correct time, which combusts in contact with the hot air. Thus, no matter how well diesel lubricates, it never goes near the parts that need lubricating. Now if we use the example of a semi diesel such as the early "diesel" saws, we could induce the charge via the crankcase in traditional 2 stroke style. The downside is the fact that semi diesels are typically large displacement for their power and are not the most convenient to start.
We are now left with the prospect of a dry sump lubricated chainsaw with a mechanical injector pump and injector, (possibly a mechanical unit injector) which by necessity will have to be either 4 stroke or we could add a blower to scavenge the combustion gasses and run the 2 stroke cycle ala Detroit Diesel - still need camshaft and timing gears etc. Turbo charging optional. Conversely we could run an electronic injection system, (with a battery included) which all adds weight.
I love the diesel process, but I can't really see its application in small power equipment.
I am not convinced that the modern "diesel chainsaw" in the youtube clip was actually a diesel anyway, didn't sound right.


I think that the saw in the video just had a bad case gasket and sucking bar lube into the crankcase and burning it. If not he just pored more oil into the fuel tank. I am sure its a gasoline two stroke.
Back to the diesel saw.
Could they run some fuel into the crankcase for lube and still use a mechanical injector in the cylinder. They could pressurize the crankcase with another piston like the old Mac BP1 did and force the air, fuel mix to the combustion chamber via transfer ports.

Later
Dan
 

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