Any news on gas engine CUTS?

[MHarryE]

I just replaced my 22HP John Deere rider 48" deck with a Kubota G2120 54" deck. I was a little concerned dropping power and adding the hydraulics (power steering) but the result in heavy grass is completing our 4 acre lawn in 1/3 the time plus doing a much better job. The Diesel, although lower power, will pull right through the tough spots where the gas engine just died. Back to sump ke physics, Diesel cycle vs Otto cycle. I list many of our tractors but don't list the gasolines - we have 4 Farmall A's, 2 M's and a Super C sitting around that get a little use running grain augers and the like. Our first diesel, a Case 400 Super Diesel in 1956, shut the door on ever having a gas tractor except for odd little things.

 

[GManBart]

So what your saying is that if I drive my wives car at a sustained speed of say 60 MPH with a trailer that is at the weight limit of its recommended pulling capacity right at its High torque output with the air conditioner running it wont last long? Basically then the gassers of old would not last long according to your theory, but in fact there are so many old gassers around here still running that I am simply confused by your statement.

No, that's not what I said, or was trying to say. First off, virtually nobody puts a trailer at max weight behind their car and then drives around for the next 10-20 years. They tow a little bit here and there, which is very different. Also, a car towing a trailer down the road, on level ground, at 60mph is turning the same rpm as it would be without the load....hills and transmission shifting will change that, of course. That rpm still won't be anywhere near the equivalent of what PTO speed is on a tractor. On level ground the load will change the manifold pressure the engine is producing, but that isn't a number we traditional use when talking about automobile engine.

If you took your wife's car on the highway and ran it at whatever speed equated to the engine producing something like 85% of it's available power, then you'd have a good comparison to a tractor at PTO speed. It wouldn't last long in that scenario, because cars and light trucks have light duty-cycle engines that aren't intended to put out rated power for extended periods of time.

You can argue about what "wouldn't last long" might be, but regardless, it won't last as long running at very high power settings as it will if it's operated the way cars are usually driven.

Please explain how a motor designed to run a flat torque curve between 2000 to 3000 RPM of any fuel with todays building methods wont last long when being used at their recommended PTO Speed. I would really like to know why I can switch so many different industrial engines built with actual car engines from the same manufacture when Propane powered industrial use is considered. Yes there are some differences but not near as many as one would think and these industrial use engines do not have short life spans and are not worked under their operating speed for very long. In fact they are used in many cases very hard and running 3 shifts around the clock for at least 7 days out of the week and do many more hours then most folks will accumulate on their scut or cut.

I never addressed this topic at all. If you can find an example of a gasoline engine fitting this description that would be suitable for use in a tractor, we'd all like to see it.

 

[aczlan]

If you took your wife's car on the highway and ran it at whatever speed equated to the engine producing something like 85% of it's available power, then you'd have a good comparison to a tractor at PTO speed. It wouldn't last long in that scenario, because cars and light trucks have light duty-cycle engines that aren't intended to put out rated power for extended periods of time.
You can argue about what "wouldn't last long" might be, but regardless, it won't last as long running at very high power settings as it will if it's operated the way cars are usually driven.

How about forklift engines? Forklifts are available in spark ignition (Gasoline or LPG) or Diesel models and they run 8-10k hours without needing any engine work if maintained.

Aaron Z

 

[paulfun9]

How about forklift engines? Forklifts are available in spark ignition (Gasoline or LPG) or Diesel models and they run 8-10k hours without needing any engine work if maintained.

Aaron Z

More than fork lift engines were made by Nissan, Toyota that fit this subject very well. This is exactly my point by the way. If industrial engines built for gas can be converted to propane for industrial use with nothing more than an intake and cam change and last for years under heavy use why does no one think a suitable gas engine could be designed to use in basic duty on a scut or a cut.

I wont argue which would be better but I do say that if one wanted to build a long stroke short duration engine with good cyl mean pressure at lower RPM it would not fail being used at what we consider to be PTO speed even while running the attachment for extended periods In fact, in a gear or shuttle application I can actually see a benefit due to the ability to use more RPM during transit which most diesel engines are not designed to give making for quicker travel time to a job or for more fuel. In actuality it could be more useful overall because even being built for a target PTO RPM it would still be able to rev higher and have useable power when doing so.

Its actually silly to think that one could not be built that would fit our need and last when we look at all the 200 and 300 thousand engines that are prevalent in cars and trucks today even thou we are not running them regularly at full load many of those cars and trucks get driven much harder than our tractors we just don't see it as doing so. My wives car has towed that trailer across this country of ours and back now and its still running and not smoking or anything and the speedo is showing something in the 230,000 range right now with my abusive 10,000 mile oil change intervals on regular oil. Toady is the first time in months that it will be driven without the trailer hooked up and with me driving and my balls to the wall driving style even that cant be considered a break for it.

So again I ask why cant a gas engine be built that will work in a small tractor?

 

[GManBart]

How about forklift engines? Forklifts are available in spark ignition (Gasoline or LPG) or Diesel models and they run 8-10k hours without needing any engine work if maintained.

Aaron Z

Again, this is apples-to-oranges. Forklift engines run pretty much like car engines in that they're rarely at near maximum rated power for extended periods of time. They spend most of their life idling, or at low power settings, not droning away at full throttle for thousands of hours.

 

[MossRoad]

Forklifts don't do much "hard" work. They just go back and forth, more than half the time with no load, and they use a hydraulic pump to lift. They do run a very long time, but again, not much load on them.

As I've mentioned many times, my late 70s IH2500b was a 50PTO HP gas engined tractor loader. It was also HST. Full cab, loaded tires, etc... about 8000#. It was also available with a diesel engine. Here's the specs for both engines below. As you can see, the diesel is larger and it has a more HP. Really, if you build a large displacement gas engine designed to do the work intended, you'd have to build a larger diesel engine to do the same work. It will cost a lot more, too. However, the diesel will be able to hold in the the torque curve longer, last a lot longer and use considerably less fuel. In and HST application like mine, it was recommended to run the thing at PTO rpms constantly. The diesel was much more fuel efficient and from talking to the guys at the industrial repair place I used a few times, the diesel was allegedly going twice as many hours as the gas before rebuilds under normal use. This was a late 70's design.

With that said, I had no issues with power and the gas engine. In a modern HST CUT or SCUT designed for mostly non-earth engaging tasks ( dirt plowing fields and pulling stumps), I'd have no issues with a gas engine. Its just turning a pump. You have to wonder why they stopped putting gas engines in them, then. It's probably because the diesel works better, lasts longer, is easier to work on at the shop, less parts to stock, and the manufacturer can charge more and make more profit.

Engine Detail:
International Harvester D-239
diesel
4-cylinder
liquid-cooled
239 ci [3.9 L]
Power: 67 hp [50.0 kW] (gear)
80 hp [59.7 kW] (hydro)
Compression: 16:1
Rated RPM: 2200 (gear)
2400 (hydro)
Oil capacity: 10 qts [9.5 L]
Coolant capacity: 14 qts [13.2 L]

Engine Detail:
International Harvester C-200
gasoline
4-cylinder
liquid-cooled
200 ci [3.3 L]
Power: 66 hp [49.2 kW] (gear)
74 hp [55.2 kW] (hydro)
Compression: 7.3:1
Rated RPM: 2200 (gear)
2400 (hydro)
Oil capacity: 7 qts [6.6 L]
Coolant capacity: 12 qts [11.4 L]

 

[GManBart]

More than fork lift engines were made by Nissan, Toyota that fit this subject very well. This is exactly my point by the way. If industrial engines built for gas can be converted to propane for industrial use with nothing more than an intake and cam change and last for years under heavy use why does no one think a suitable gas engine could be designed to use in basic duty on a scut or a cut.

I wont argue which would be better but I do say that if one wanted to build a long stroke short duration engine with good cyl mean pressure at lower RPM it would not fail being used at what we consider to be PTO speed even while running the attachment for extended periods In fact, in a gear or shuttle application I can actually see a benefit due to the ability to use more RPM during transit which most diesel engines are not designed to give making for quicker travel time to a job or for more fuel. In actuality it could be more useful overall because even being built for a target PTO RPM it would still be able to rev higher and have useable power when doing so.

Its actually silly to think that one could not be built that would fit our need and last when we look at all the 200 and 300 thousand engines that are prevalent in cars and trucks today even thou we are not running them regularly at full load many of those cars and trucks get driven much harder than our tractors we just don't see it as doing so. My wives car has towed that trailer across this country of ours and back now and its still running and not smoking or anything and the speedo is showing something in the 230,000 range right now with my abusive 10,000 mile oil change intervals on regular oil. Toady is the first time in months that it will be driven without the trailer hooked up and with me driving and my balls to the wall driving style even that cant be considered a break for it.

So again I ask why cant a gas engine be built that will work in a small tractor?

Nobody has said a gas engine couldn't be built to work in a tractor. The fact is, right now nobody is making an engine like that. If they did, and incorporated all of the modern stuff like direct injection, etc, much of the cost savings of gasoline engine construction versus diesel would be gone....narrowing the gap in purchase cost.

The other thing is that it's highly unlikely that a tractor manufacturer would sell any additional machines if they suddenly started offering a gasoline alternative, so they would be wasting a lot of money developing a new engine for zero sales increase.

The point remains that your wife's car towing a trailer is very different from a tractor operating at PTO speed for thousands of hours. It's still only a partial load, with few peak power loads that aren't sustained for very long. Put it this way....put the trailer behind her car, head onto the highway, put the car in first gear, and run the engine up to 85% of max....let it sit there for maybe 8 hours a day. How long will it last? Not very long at all. Do the same thing with a tractor and it's going to last years, or decades.

I actually know a guy who got into a huge conflict with Chevrolet about a newly purchased Corvette. The details don't really matter (and I'm not endorsing his behavior), but he took it out on the highway, put it in first gear and ran it near redline until it blew up....he didn't get very far. If you did that with anything that has a heavy duty diesel engine and you'd just drive pretty slowly until you got tired of it, but it's not going to hurt the engine.

 

[crazyal]

One thing about forklifts is they often get used indoors. the exhaust from a diesel would make it a poor choice to run indoors. That's why you almost always see electric or propane. But that's really what all of this comes down to. You pick the best fuel type for the job. For long hours with heavy loads a diesel is great choice.

 

[paulfun9]

Nobody has said a gas engine couldn't be built to work in a tractor. The fact is, right now nobody is making an engine like that. If they did, and incorporated all of the modern stuff like direct injection, etc, much of the cost savings of gasoline engine construction versus diesel would be gone....narrowing the gap in purchase cost.

The other thing is that it's highly unlikely that a tractor manufacturer would sell any additional machines if they suddenly started offering a gasoline alternative, so they would be wasting a lot of money developing a new engine for zero sales increase.

The point remains that your wife's car towing a trailer is very different from a tractor operating at PTO speed for thousands of hours. It's still only a partial load, with few peak power loads that aren't sustained for very long. Put it this way....put the trailer behind her car, head onto the highway, put the car in first gear, and run the engine up to 85% of max....let it sit there for maybe 8 hours a day. How long will it last? Not very long at all. Do the same thing with a tractor and it's going to last years, or decades.

I actually know a guy who got into a huge conflict with Chevrolet about a newly purchased Corvette. The details don't really matter (and I'm not endorsing his behavior), but he took it out on the highway, put it in first gear and ran it near redline until it blew up....he didn't get very far. If you did that with anything that has a heavy duty diesel engine and you'd just drive pretty slowly until you got tired of it, but it's not going to hurt the engine.

No one is arguing the difference in what we consider normal loads on the engine but I will also say that if your friends car had been a jeep pulling a load that was enough to keep him from attaining max RPM while dragging it in first gear he would not have been able to blow the engine. Now we can talk about the other variables all you want like the overheat that would transpire because the cooling system would not handle the heat but if the engine was built for the use it would not blow nor overheat. Now for the blowing up due to over revving for a long period of time what would happen if we set up a diesel to be able to attain the same rpm that the gas engine in your friends car can and did the same thing even with it being built to make max power well below max RPM? Ever see what happens when a diesel has pump failure and keeps on going up in RMP till it blows?

 

[buickanddeere]

I have enough problems with gas in my small engines ... I sure don't want my tractor I'm wanting to last for a LONG time to suffer the same fate ... don't have to look too far to see its a headache not worth having if you can help it:

http://www.tractorbynet.com/forums/...-damage-caused-ethanol-gasoline-new-post.html

Maintenance costs? Yea, I get that comment a lot with my car. Factory oil change interval for that is 10K miles on the oil. Do you do that in your gasser? And before the gubment changed the API spec to CJ4, it was REAL easy to use oil analysis to do extended intervals safely to 20K miles.

... and I don't have to buy any spark plugs (or plug wires etc.)

Please tell us with 2015 vehicles how often plugs, wires, caps, rotors and points need to be changed. Don't forget the automatic choke and the heat riser valve too. How much does one Duramax injector cost ?