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The longer this thread goes on the more variables. So, I guess one can't simply say, "Onan's have more torque". Threads like this one are fun to read.
I still say the diesel Yanmar rules! I don't care how many numbers you put up there. Oh and it will still be running when the Onan has thrown a rod. LOL........... :ROFLMAO:
I guess we all got a physics lesson from Knock Knock.......... ;)
 

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That’s why also I love the yanmar. I know it will go the distance. When I hear story’s like a member plowing 6 acres repeatedly and racking up 4500 hrs and still going strong I feel warm and fuzzy. I hope mine last me a lifetime! That said I still have mad respect for my onans. I can hook up to a tractor down back with four flat tires and drag it up to the garage at half throttle and they love it👍🏻 A friend asked me which one I’d would use for what and I replied whatever ones closet to the door goes out first! 😂👍🏻
 

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No argument from me about diesel's. I've had a few of my own in my lifetime and a lot of them in my working career. Other than they are too expensive, stink the place up, and don't fare well in cold weather. (Best keep em warm) Just don't break it. In the case of JD's, (Yanmar's) you are likely to see a lot of "NLA's" when looking for parts. And if the worst happens, you're not likely to find any sort of appropriate replacement engine.

When it comes to diesel fuel, I am totally anal about getting that crap on my shoes. I walk around fuel pumps like I'm walking on eggs. There is nothing that will spoil a trip faster than tracking diesel fuel into your car.

Other than that? There great!
 

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well, without getting into a physics lesson, its more about how the engines deliver their power than what their peak numbers are.

To borrow a pic from earlier in the thread:



if you zoom in you can see the torque "curve". A gas engine has a fairly narrow torque "band". in the pic, you can see it peaks in the 3400-3600 range and starts dropping off rather sharply below 3400. It looses approx 4 lbft between 3600 and 3000 rpm. That's roughly a loss of 25% from the peak numbers in only 600 rpm. Note they don't give you anything on the chart below 3000 rpm. That's the nature of gas engines, you generally need rpm to make power. A lot of it has to do with compression ratios, cam lift and timing, etc.

Now here's a 3 cyl Yanmar:

torque -

Horsepower-


source: https://yanmarengines.com/wp-content/uploads/2020/02/3TNV74F-NDYA.pdf

That's not for the 322/332 diesel, but (for the purposes of this discussion) it's not the numbers we want to look at, we want to look at how the power is delivered.

Notice the Yanmar diesel comes in very early and pretty much peaks at 1800 rpm and carries it almost to the rpm peak on the chart. That's the nature of how diesels deliver power. They make close to their peak torque almost off idle and carry pretty much the same number until they cross the HP line.

What all this means is that if you spin your gas engine around 3400-3600, you get the peak torque out of them and the gas diesel numbers look similar (if not the same).

But a diesel engine makes close to it's peak torque just off idle and carries it to it's rpm peak (almost). What this means is the torque you need to spin pumps, run accessories, implements, etc is available nearly off idle. this means you don't have to spin it as hard to get the same power you would from a gas engine. It also means you're less likely to have a diesel "bog" on you as you are a gas engine.

you also have to factor in the durability of the engines. An IDI diesel runs somewhere in the range of 22:1 compression, which means much of the engine has to be built to handle that kind of stress. That (usually) translates in to a more durable engine that runs/lasts longer than a gas engine.

Diesel is no cure all though, there's drawbacks like weight, larger fluid capacities (IE:$$$), handling diesel (some people don't like it) and more.

It's about matching the engine choice to your intended use. If you're just cutting the lawn and a little light gardening work, gas is probably what you want. But if you have a larger property with some heavy work needed (ie: tiller, brushhog, large snowblower, etc), diesel might be the better choice.

Both are good choices, it's just a matter of whats the best choice for YOU....
 

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Great info! I also really dislike diesel on me, my clothes, ect. I had to sell my beloved 86 3/4 Chevy with built 350 because it wouldn’t pull my toy hauler. Lots of hp but no towing torque. Wound up with a 07 duramax. Not a show truck but massive power. At 200k miles I’m hoping it goes another 220k. I know my onans will break, throw rods, cam bearings, head gaskets (did one the other day) ect. That’s why I have a spare on the shelf and another spare after that. I don’t have a fancy vanguard yet but hey I’m a cheap wad! 😂
 

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Getting off the torque wagon for a minute, does anybody know if the diesel versions of our tractors are geared any differently? All of the above is good information but it made me wonder about that. It's true, most diesel turn a lot slower than their gas equivalent, and if the Yanmars do, they either need a gear change or their ground speed would be much less. Maybe not?

I've had a couple of GMC Subs with the 6.2-liter diesel engines. Along with twenty of them in our fleet at the time. What a POS that engine was. But, the trucks all had to have the rear ends replaced by GM as the engines just burned out with the 4:11 rear gears. Gm spec'd those trucks, we didn't. They did it in our shop for free. We later replaced them with Izuzu's. Along with around 100 Chevy v8's. (There was a gas shortage) The bean counter loved those Izuzu's, the drivers hated them. Not enough power. In the winter months, we had so many issues with gelled fuel we told the route drivers to leave them run all night. The neighbors didn't care for that at all as most of the fleet was driven home by the route drivers. That didn't go well for the company image.

Just curious. And it's too cold in the garage today to work.
 
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Great info! I also really dislike diesel on me, my clothes, ect. I had to sell my beloved 86 3/4 Chevy with built 350 because it wouldn’t pull my toy hauler. Lots of hp but no towing torque. Wound up with a 07 duramax. Not a show truck but massive power. At 200k miles I’m hoping it goes another 220k. I know my onans will break, throw rods, cam bearings, head gaskets (did one the other day) ect. That’s why I have a spare on the shelf and another spare after that. I don’t have a fancy vanguard yet but hey I’m a cheap wad! 😂
I mentioned the GM 6.2 above saying it wasn't a good engine. But it was better than that converted 350 small block Chevy decided to turn into a diesel. As for longevity, I'm sure you will get that many miles out of the Duromax. It's a great engine. I had 350K on my F250, (Farmall) sold it to a (person of southern decent) and as far as I know, it's still going. He was happy to get it.

I don't see the attraction in Vangaurds. But I can't say I know anything about them. Never was a Briggs fan. I really like the Kohler Commands. So far. If you get rid of that silly electronic ignition. They fit into the tractor very well, have lots of power, and are priced decently. I'm not one to follow the herd, but I think folks should take a closer look at these engines.
 

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Getting off the torque wagon for a minute, does anybody know if the diesel versions of our tractors are geared any differently? All of the above is good information but it made me wonder about that. It's true, most diesel turn a lot slower than their gas equivalent, and if the Yanmars do, they either need a gear change or their ground speed would be much less. Maybe not?

I've had a couple of GMC Subs with the 6.2-liter diesel engines. Along with twenty of them in our fleet at the time. What a POS that engine was. But, the trucks all had to have the rear ends replaced by GM as the engines just burned out with the 4:11 rear gears. Gm spec'd those trucks, we didn't. They did it in our shop for free. We later replaced them with Izuzu's. Along with around 100 Chevy v8's. (There was a gas shortage) The bean counter loved those Izuzu's, the drivers hated them. Not enough power. In the winter months, we had so many issues with gelled fuel we told the route drivers to leave them run all night. The neighbors didn't care for that at all as most of the fleet was driven home by the route drivers. That didn't go well for the company image.

Just curious. And it's too cold in the garage today to work.
gearing is kind of irrelevant if you're talking about a hydrostatic rig. The engine drives a pump, which drives the transmission.
 

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I mentioned the GM 6.2 above saying it wasn't a good engine. But it was better than that converted 350 small block Chevy decided to turn into a diesel. As for longevity, I'm sure you will get that many miles out of the Duromax. It's a great engine. I had 350K on my F250, (Farmall) sold it to a (person of southern decent) and as far as I know, it's still going. He was happy to get it.

I don't see the attraction in Vangaurds. But I can't say I know anything about them. Never was a Briggs fan. I really like the Kohler Commands. So far. If you get rid of that silly electronic ignition. They fit into the tractor very well, have lots of power, and are priced decently. I'm not one to follow the herd, but I think folks should take a closer look at these engines.
Cheese and rice i worked on those 350 "conversion" diesels at a chebby shop right before I got out of high school. They were the worst!
I sold my ex FIL's 89 Dodge Cummins with 859000 miles on it still running awesome. Now tell me about the 7.3 furds or the duracraps........... :ROFLMAO:

Man we have gotten WAY off topic.
I really am sorry BUT hey it's fun................... :ROFLMAO:
 

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Cheese and rice i worked on those 350 "conversion" diesels at a chebby shop right before I got out of high school. They were the worst!
I sold my ex FIL's 89 Dodge Cummins with 859000 miles on it still running awesome. Now tell me about the 7.3 furds or the duracraps........... :ROFLMAO:

Man we have gotten WAY off topic.
I really am sorry BUT hey it's fun................... :ROFLMAO:
I can tell by you're handle where your heart lies. But that's OK. To be honest, I never really knew why we stayed away from Cummins back in the day. Likely price. Dad had one in his Emeryville. But you shouldn't put the Dodge name in front of the Cummins as if they had anything to do with it other than signing a contract that kept Cummins in business. And Dodge to boot as they were pretty much in the tank before they went out of house to find something to sell. My only question is? Did they ever make a quiet Dodge? Nothing converts good fuel into noise better than a Dodge. And you should have more respect for those Furds. Over 40 years being the best seller. Maybe you're missing something.

Are we trashing talking here? :)
 
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I can tell by you're handle where your heart lies. But that's OK. To be honest, I never really knew why we stayed away from Cummins back in the day. Likely price. Dad had one in his Emeryville. But you shouldn't put the Dodge name in front of the Cummins as if they had anything to do with it other than signing a contract that kept Cummins in business. And Dodge to boot as they were pretty much in the tank before they went out of house to find something to sell. My only question is? Did they ever make a quiet Dodge? Nothing converts good fuel into noise better than a Dodge. And you should have more respect for those Furds. Over 40 years being the best seller. Maybe you're missing something.

Are we trashing talking here? :)
Just an fyi: that 40 years best seller is a bit of a marketing ploy.

if you add chevy and gmc truck sales together, gm sells more trucks than Ford some years, if not a lot of those years.

I also seem to recall that ford says “F-series”, which includes everything from the f-150 to all the larger trucks of the “F series” in reporting thier sales numbers. Memory is a little foggy these days, so I might be wrong on that point.

I lean towards Ford by they way, but have had gm’s and chysler’s as well. I currently have a 2016 F-150 crew lariat ecoboost. They’re all good and they all have their own…”issues”.

One last point:

duramax - originally designed by isuzu
Powerstroke - originally design by navistar

Common practice in the industry, especially with diesels.
 

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The Yanmar is a superb engine and I'm not trying for an argument here but we need to be looking at the correct graph. The onan torque curve is the top one where it makes ~ 27 ft-lbs at full (3600 rpm). The key is as the engine encounters load and rpm is reduced with grass/snow whatever, the torque INCREASES until it reaches its max of 31.7 ft-lbs @ ~ 2000 rpm. So there is a ~20% increase in torque which is why the onan/JD ads used to mention its tremendous lugging ability.

Rectangle Slope Line Font Parallel
 

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The Yanmar is a superb engine and I'm not trying for an argument here but we need to be looking at the correct graph. The onan torque curve is the top one where it makes ~ 27 ft-lbs at full (3600 rpm). The key is as the engine encounters load and rpm is reduced with grass/snow whatever, the torque INCREASES until it reaches its max of 31.7 ft-lbs @ ~ 2000 rpm. So there is a ~20% increase in torque which is why the onan/JD ads used to mention its tremendous lugging ability.

View attachment 273250
No worries, no offense taken, no argument required.

But I was looking at the proper chart. But you want the bottom curve, which is continuous rating. The top curve is peak ratings. On continuous, it never tops 26 hp. At least not on that chart.

peak numbers are mostly marketing garbage on almost every product out there be it engines, motors, audio equipment, etc. It makes the numbers look better. If you really want to know how and engine performs, you want to look at the “continuous” curve if you want to know how its going to perform on an everyday basis.

:)
 

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well, without getting into a physics lesson, its more about how the engines deliver their power than what their peak numbers are.

snipped stuff to save room...


if you zoom in you can see the torque "curve". A gas engine has a fairly narrow torque "band". in the pic, you can see it peaks in the 3400-3600 range and starts dropping off rather sharply below 3400. It looses approx 4 lbft between 3600 and 3000 rpm. That's roughly a loss of 25% from the peak numbers in only 600 rpm. Note they don't give you anything on the chart below 3000 rpm. That's the nature of gas engines, you generally need rpm to make power. A lot of it has to do with compression ratios, cam lift and timing, etc.
I was just pointing out that using the graph in the previous post shows both the continuous or peak torque value INCREASES as the engine lugs down from 3600 rpm to ~ 2000 rpm which doesn't agree with your earlier statement above (and don't understand comment about no data below 3000 rpm?). I agree with your point on continuous ratings (don't get me started on my 5HP rated shop vac) ;) but the 318 has been rated and thought of as an 18HP tractor for decades.
 

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Just an fyi: that 40 years best seller is a bit of a marketing ploy.

if you add chevy and gmc truck sales together, gm sells more trucks than Ford some years, if not a lot of those years.

I also seem to recall that ford says “F-series”, which includes everything from the f-150 to all the larger trucks of the “F series” in reporting thier sales numbers. Memory is a little foggy these days, so I might be wrong on that point.

I lean towards Ford by they way, but have had gm’s and chysler’s as well. I currently have a 2016 F-150 crew lariat ecoboost. They’re all good and they all have their own…”issues”.

One last point:

duramax - originally designed by isuzu
Powerstroke - originally design by navistar

Common practice in the industry, especially with diesels.
You may be right about the sales figures but I doubt it. GM is not one to let an advertising gimmick go unchallenged. As an example, those silly ads where that dude drops a toolbox full of lead to prove how weak the Ford aluminum box is. If there was a ligit challenge to Ford's F series sales dominance I'm sure GM would have exploited it. They have not. But they now use mostly aluminum. And the sales figures would surely be examined by every GM leaning magazine. They are not.

And yes, Navistar produced the 7.3 used in earlier Ford trucks. That' why they are referred to as "Farmalls" coming from the original International Farmall name. There is a lot of back-scratching among manufacturers these days. The Ford ten-speed transmission was designed by Allison, and likely produced under some license agreement. The story going around was Ford traded Aluminum fabrication technology for the allison 10 speed. About the same time GM decided to offer a ten speed.

One only has to look at the various brands to see the similarities that are obvious between them. It's no accident that happened. So, in the end, they all get a little better. It's really down to what fits your fancy in the style department and price range. I personally, go with what got me there. I once was an avid Chevy guy but there came a day I couldn't buy another one as they became nothing but junk. I bought a Ford, and virtually never had an issue with any of them now over 30 years and somewhere around 2 million miles. I like the looks. It drives like a dream. It's comfortable and good looking in my eye and it's economical. Why change? Maybe because they are getting too damn expensive. Ford surely isn't giving their trucks away. I'll keep this one until it takes me to the graveyard will have to do. Hopefully, we both last that long. But if not, I may just take a closer look at a Toyota Tundra. It's more affordable for sure.
 

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I was just pointing out that using the graph in the previous post shows both the continuous or peak torque value INCREASES as the engine lugs down from 3600 rpm to ~ 2000 rpm which doesn't agree with your earlier statement above (and don't understand comment about no data below 3000 rpm?). I agree with your point on continuous ratings (don't get me started on my 5HP rated shop vac) ;) but the 318 has been rated and thought of as an 18HP tractor for decades.
We must be looking at two different charts then. The torque curve actually reads left to right.
So if you read across from 3000 rpm, it intersects the curve (continuous) at 22 ftlbs. As rpm increases, so does the torque and vice versa as the rpm drops.

there’s no engine on the face of the planet that makes more torque as the rpm drops. Not one.

regardless, my point was to the fact that a diesel curve is more or less flat almost off idle and the torque curve for petrol engines starts low and builds with rpm. Gas engine needs rpm to make their max numbers. Diesels also need rpm to make max numbers, but they make more at lower rpms so the curve is more like a “table” where a gas engine curve is more like a “hill”..
 

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Yup, we're clearing not reading the data the same way and sorry it is so blurry. The upper two curves are torque with torque in ft-lbs on left y-axis and in N-m on right y-axis. The engine RPM is on horizontal axis from 1800 to 3600 rpm. if you calculate the HP at the 3600 rpm point using the point off the graph (peak torque) of ~ 27 ft-lbs, you get 18HP.
 

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We must be looking at two different charts then. The torque curve actually reads left to right.
So if you read across from 3000 rpm, it intersects the curve (continuous) at 22 ftlbs. As rpm increases, so does the torque and vice versa as the rpm drops.

there’s no engine on the face of the planet that makes more torque as the rpm drops. Not one.

regardless, my point was to the fact that a diesel curve is more or less flat almost off idle and the torque curve for petrol engines starts low and builds with rpm. Gas engine needs rpm to make their max numbers. Diesels also need rpm to make max numbers, but they make more at lower rpms so the curve is more like a “table” where a gas engine curve is more like a “hill”..
Yup, we're clearing not reading the data the same way and sorry it is so blurry. The upper two curves are torque with torque in ft-lbs on left y-axis and in N-m on right y-axis. The engine RPM is on horizontal axis from 1800 to 3600 rpm. if you calculate the HP at the 3600 rpm point using the point off the graph (peak torque) of ~ 27 ft-lbs, you get 18HP.
could be. The pic is pretty fuzzy on my screen.
 

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I had a Chevy truck that had the 350 Buick engine converted to diesel. It was replaced with a Oldsmobile 403 small block. That was fun at a auto parts store to explain what I had.
 
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