BertP
Edmonton, Alberta, Canada
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Joined: 11/07/2003
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Quote:Sure, it will burn more fuel, probably break more often, and not last as long..but hey a gas engine COULD be manufactured that would keep up with the diesel. Just kidding a bit Bert. Face it, if there was a realistic way that a gas engine could be developed that made some type of sense for heavy equipment or heavy hauling, we'd have it. Some heavy equipment/trucks costs hundreds of thousands or even millions of dollars, and they all have some form of diesel engine in them. Almost anything is possible, it just doesn't always make sense.
And that has been my point all along. Gas engines can do anything that diesels can. But, since they burn more fuel doing it, it generally does not make sense to do that. Also, since diesels burn less fuel and are, therefore, more economical to run, far more development work has gone into building medium and heavy duty diesels than gassers. After all, if they can both do the job, why use the one that burns more fuel and increases your operating costs? Economics.
Quote:I've owned quite a few aircraft, all powered by gas engines. Certainly for light weight in a piston powered aircraft it only makes the most sense. A six cylinder Cat in a two place aircraft makes as much sense as a 8.1 in a D8.
This is an interesting comparison. In the case of the diesel vs gasser, the economics play in favor of the diesel and that's the way that the industry has gone. However, in the case of aircraft engines, you will be had pressed to find a new piston engine developing more than around 500 HP. Why? Because the turbine has taken over in that market. Yet, contrary to the diesel vs gasser scenario, the turbine consumes more fuel than the gas equivalent. So, why has the turbine taken over? Simply priorities. As you pointed out, weight is an extremely important factor in aircraft engines. A turbine weighs a fraction of a similarly powered piston engine, so it has a major advantage. Also, the durability of the turbine far outstrip that of any piston engine. So, in spite of the fact that the turbine burns more fuel than a piston engine, the overall economics of the turbine win, just like the diesels do in trucks.
Quote:Our smallest piece of equipment is an ASV RC50, it has a 50hp Cat diesel in it. It is a wonderful piece of machinery for it's inteded purposes. The older, similarly sized pieces of equipment that were gas powered are considered antiques and are almost impossible to sell. Same with some types of boats, if they don't have a diesel or two they just aren't considered as desireable, largely due to safety considerations.
Diesels can be excellent engines and I have never knocked them. I was just trying to address the falicy that gassers are incapable of doing any heavy work. They have for years and, if technological developments decrease fuel consuption of them to the levels of diesels, we may see them again.
Quote:People that make a living with machinery demand the best tools for the job. For years now that has overwhelmingly been accomplished with diesel powerplants. It's not due to slick marketing or misinformed consumers. Why would someone want to burn more fuel and be less safe for goodness sake?
Absolutely not. Diesels burn less fuel than gassers for a given job, so they are more economical. And that is why diesels are so prevalent in the heavy equipment.
Bert
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59022
MT
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Joined: 08/04/2004
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Quote:Absolutely not. Diesels burn less fuel than gassers for a given job, so they are more economical. And that is why diesels are so prevalent in the heavy equipment.Bert
Diesel engines convert their power to run electric motors on heavy mining equipment, like the kind you find at strip coal mines, just as diesel/electric locomotives operate. I suppose you could use a V-16 gas engine, but you'll need an extra tank car for the fuel required.
With diesel topping $2/gal and $3.50/gal in Canada, the chances of gasoline following suit next Spring are pretty good. The current reasoning is because of the switchover to heating oil. If the NorthEastern USA has a mild winter, the terminals will be filled with excess diesel and the prices will drop. If, however, it's a nasty mix and with lots of cold weather, the prices will remain high.
Everytime a refinery is taken out of service for maintenance, you'll see a rise in prices the next day.
It's been diesels for us, practically forever. We farm and run a trucking operation simutaneously. We use 2000 gals of red every three months (farm diesel) and pay the same pump prices for the OTR's as you do. With engines lasting nearly forever these days, it's hard to go back to gassers. Nearly every truck engine has more than 550,000 miles on them. Of the four farm generators, only one has been rebuilt at 22,000 hrs. A gas engine wouldn't survive that long.
Slowing down this past Summer has helped increase mileage. We have a 75 mph limit/70 for trucks here and by slowing down to 65/60 has helped conserve = 8mpg.
George
Lifelong tipi, wall tenter/mule packer. 850-ac in Montana.
61 U404, 99 Dodge V10, 79 Airstream www.nativeradio.com
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Ag Teacher
Oklahoma
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Joined: 04/30/2001
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Quote:Quote:As far as the Italian with no Face (must have lost it shaving), engine power is measured in a term called Horsepower. The 8.1 G.M. engine has more horsepower than any diesel engine offered in a pickup.
You are correct in saying that the vortec 8100 has more horsepower in stock form than any of the 3 diesels available in the US light duty truck market. Now, please explain why that engine is rated to tow less than the (by your standards of engine power) lower powered diesel engines? The reason, of course, is that horsepower is only one measurement of engine power. It is also a measurement that is derived from a formula applied to another form of engine power measurement called torque....AND....Regardless what you say, think, or feel about horsepower versus torque, the diesels have more available torque. It must be that the torque output of these engines has just a tiny bit to do with the irrefutable fact that they are rated to tow more, with all other things being equal.
Why do I have to explain tow rating and torque when my post was related to horsepower. The kid said the diesels have more power. If we measured power in lb/ft, the diesel would be superior. But we don't, me measure it in horsepower and regardless of the tow ratings, the 8.1 vortec has more horsepower than any diesel currently offered in a pickup.
2005 Explorer by Frontier RV T265
Yamaha EF3000iSEB Generator
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bluenote
Michigan
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Joined: 10/15/2001
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Quote:Why do I have to explain tow rating and torque when my post was related to horsepower. The kid said the diesels have more power. If we measured power in lb/ft, the diesel would be superior. But we don't, me measure it in horsepower and regardless of the tow ratings, the 8.1 vortec has more horsepower than any diesel currently offered in a pickup.
And...if you read the post accurately, you'd see I agreed with the statement that the big block has more horsepower. However, your statement seem to imply that the superior horsepower made the big block better somehow. You still have not answered the question. If the big block has more horsepower, why is it not rated to tow more than the diesel? Case in point...a Chevy 3500 dually with the LLY Duramax and Allison is rated for 1,500 more GCVWR than the equivalent truck with a vortec 8100 (actually, the big block has to have 4.10 rear gears to get even that close in ratings). Since you feel that horsepower is the "only" way to measure engine power, I find it interesting that you can't explain why the lower HP, yet higher torque diesel has the superior tow rating.
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willald
NC
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Joined: 07/15/2002
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Quote:You still have not answered the question. If the big block has more horsepower, why is it not rated to tow more than the diesel?....Since you feel that horsepower is the "only" way to measure engine power, I find it interesting that you can't explain why the lower HP, yet higher torque diesel has the superior tow rating.
I'll answer that, or at least try to.
As we all know, many, many, MANY factors go into tow ratings (I'm strictly talking about GCWR, not GVWR). GCWR rating is based mostly on how much weight the drivetrain can handle. How much weight a drivetrain can handle, is determined by several factors, not the least of which is - LONGEVITY OF SERVICE (how long can a drivetrain generate a given amount of power before wearing out).
It IS true (no matter what diesel disciples will try to say), that the more horsepower you can generate, the faster/better you can move a load. As has been said many times, you can generate horsepower two ways - high torque at low rpm, or low torque at high rpm. Both ways, generate the same horsepower. However, typically, the former of those (high torque at low rpm) is more efficient, and likely to last longer in reciprocating (piston) engines.
As I said, many factors about the drivetrain are considered, for GCWR rating. Longevity of service is one of those factors, and is why the diesel has the higher GCWR rating. It (diesel) can handle the higher load, without wearing out as fast. Yes, the gasser can generate more horepower, and could handle more GCWR load than the diesel, since it has more horsepower. But, the gasser would NOT LAST AS LONG as the diesel, since the gasser would have to turn 5,000 RPMs all day in order to do it.
Still, it is quite possible to build the gasser V8 so it COULD turn that fast all day, and still last as long as the diesel. Would use up obscene amounts of fuel, but it could be done. If it was built that way, the gasser WOULD indeed have a higher GCWR rating than the diesel, since it has more horsepower.
But, as many have said, it gets into economics - a big block V8 gasser that could turn 5,000 RPMs all day long and still last 200,000 miles, would be a VERY expensive engine to build, and would cost too much to put in regular production trucks. Much cheaper to just give the gasser a lower GCWR rating and gear it to not turn so many RPMs. Then, offer a diesel engine with a higher GCWR rating, since even though it has less maximum horsepower, it can still generate enough horsepower to move the bigger load, and do it without twisting as hard.
Anyway, hope that answers the question, bluenote.
Will
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bluenote
Michigan
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Quote:Anyway, hope that answers the question, bluenote.
Have you ever heard of sarcasm?
I'm fully aware of the reasons why diesels can be rated to handle greater towing weights. I was just interested in seeing if Ag Teacher could explain it.
Sorry about the misunderstanding.
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wkdelsol
sun city,ca. usa
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Joined: 06/29/2004
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Quote:Quote:My German friend tells me no one drives a diesel car on the Autobon freeway,the can't keep up.
(Just my two cents)
That's very interesting. We hosted a foreign exhange student from Germany 3 years ago. His father owned a taxi firm, and most of their taxi's were diesel powered Mercedes Benz. He never mentioned any problem with driving them on the autobahn and I know for a fact that they used them out there regularly. In fact, he said that they can move right along with the fast traffic, pulling over only for the sports cars that are really hauling. Maybe a little VW diesel would run into problems, but there's no reason that any engine, regardless of engine type, couldn't maintain autobahn-type speeds when equipped with the proper gearing.
Looks like our german friends need to get together and compare stories
my friend says don't drive your diesel on the autobaun unless you want head lights blinking in your mirror.
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BertP
Edmonton, Alberta, Canada
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Joined: 11/07/2003
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Quote:Quote:Absolutely not. Diesels burn less fuel than gassers for a given job, so they are more economical. And that is why diesels are so prevalent in the heavy equipment.
Bert
It's been diesels for us, practically forever. We farm and run a trucking operation simutaneously. We use 2000 gals of red every three months (farm diesel) and pay the same pump prices for the OTR's as you do. With engines lasting nearly forever these days, it's hard to go back to gassers. Nearly every truck engine has more than 550,000 miles on them. Of the four farm generators, only one has been rebuilt at 22,000 hrs. A gas engine wouldn't survive that long.
The problem here, though, is that you are comparing medium and/or heavy duty engines to light duty ones. Will a medium or heavy duty diesel last longer than a light duty gasser? You bet! Will a medium or heavy duty gasser last longer than a light duty diesel? Absolutely! I know that medium or heavy duty gassers will be very difficult to find, but I just wanted to be sure that we are comparing apples with apples. The fact that your engines last as long as they do is primarily because of the fact that they are medium or heavy duty engines, not because they are diesels. A meticulously maintained gasser will last longer than a poorly maintained diesel and vice versa.
Quote:Slowing down this past Summer has helped increase mileage. We have a 75 mph limit/70 for trucks here and by slowing down to 65/60 has helped conserve = 8mpg.
Very true. I tended to drive faster than I normally do while on vacation this summer and my fuel bills proved it ![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
Bert
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59022
MT
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Joined: 08/04/2004
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Quote:
The problem here, though, is that you are comparing medium and/or heavy duty engines to light duty ones. Will a medium or heavy duty diesel last longer than a light duty gasser? You bet! Will a medium or heavy duty gasser last longer than a light duty diesel? Absolutely! I know that medium or heavy duty gassers will be very difficult to find, but I just wanted to be sure that we are comparing apples with apples. The fact that your engines last as long as they do is primarily because of the fact that they are medium or heavy duty engines, not because they are diesels. A meticulously maintained gasser will last longer than a poorly maintained diesel and vice versa.
Those farm generators are from old Dodge trucks that we scrapped. B Series 12 valves. Light duty engines.
Never seen a gasser last 22000 hrs in a boat or a truck, EVER!
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BertP
Edmonton, Alberta, Canada
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Joined: 11/07/2003
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Quote:Those farm generators are from old Dodge trucks that we scrapped. B Series 12 valves. Light duty engines.
I'm sure that Dodge fans will correct me if I'm wrong, but those B series engines are medium duty as far as I know.
Quote:Never seen a gasser last 22000 hrs in a boat or a truck, EVER!
22,000 hours running works out to around a million miles. There was a thread started about that a while ago and I found a Volvo that went almost 2 million miles. There were also a few trucks that went around a million miles as well, so it can and does happen. Also, if that is constant or near constant running, an engine will last longer in those conditions than when it is started and shut off frequently. I remember seeing gassers removed from cars and trucks and set up to run irrigation pumps. Those engines would run from around May till September before being shut off and would last for years.
Bert
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