General Question on Diesels

[Diggin It]

I'm not into diesels. I grew up when the only things with them were big trucks and Ag and construction equipment. Never would have heard of a small lawn mower type thing with one. Detroit Diesel and Cummins probably ruled the world.

So, what happened? Why do we have all the Asian brands now? Sort of a rhetorical question, but not entirely. Did DD and Cummins miscalculate the smaller markets? Or didn't they care?

 

[bunyip]

Diesels were always big and high compression, I suspect they don't care and as time went by the compression dropped and small engines became viable especially with small turbo units, common rail and intercoolers.
Could you imagine trying to pre heat and hand start a mower with a 25:1 compression ratio?

 

[RNeumann]

Look at the BTUs per gallon. Off the top of my head it’s something like this ratio:

Nat Gas- 60-65
Propane- 70
Gasoline- 100
Diesel- 105-110
Jet Fuel- 115

Those are rough numbers but you get the idea. Diesel provides a good bang for a given amount. Makes sense more manufacturers would be entering the market. Especially now that they’ve figure out how to inject and time the engines.

 

[Agvg]

No problem to handstart a 1cyl diesel, but on a small mover there are no point to use diesel engine.

 

[3930dave]

Did DD and Cummins miscalculate the smaller markets? Or didn't they care?

I'd say it was mostly Don't Care.

In the N. American market, manufacturers focus on Big Vehicles = Big Profits much of the time.

Other markets have other dynamics. High density regions (Asia, much of Western Europe) need compact construction equipment. Turns out, those same compact units are pretty useful here too. An local excavator commented on the first mini JCB he bought - He wasn't sure how much use he'd get out of it the first year.... turned out he was busy right up to Christmas (freeze up here), and kept it very busy the following years.

Extra complexity has come into diesels in recent years, but traditionally they provided a high-torque, fuel efficient powerplant - just what's needed for getting work Done.

Companies like Yanmar targeted small diesel applications, and excelled there.

Rgds, D.

 

[Agvg]

3 cyl, water cooled diesels are the std on small equipment today, low noice level and vibrations on those vs 1 and 2 cyl air cooled engines.

 

[Navvet]

I have a JD X495 mower with a Yanmar 3 cyl 24 hp diesel. Much more power and 1/3 the fuel used compared to my old 25hp gas.

 

[Diggin It]

I have a JD X495 mower with a Yanmar 3 cyl 24 hp diesel. Much more power and 1/3 the fuel used compared to my old 25hp gas.

That's fine, but the question is why didn't Detroit Diesel make that 3 cylinder engine for JD?

 

[Diggin It]

I'd say it was mostly Don't Care.

In the N. American market, manufacturers focus on Big Vehicles = Big Profits much of the time.

You'd like to think that a company like JD could have persuaded DD or Cummins to enter the market with their projected sales of GTs and SCUTs.

 

[Navvet]

That's fine, but the question is why didn't Detroit Diesel make that 3 cylinder engine for JD?

Why did Ford stop production on the original T-Bird, as 3930Dave said, US manufacturers concentrate on BIG ......

I also have a JD AMT626 with a Kawasaki engine ....... (and an F350 with a 7.3L Powerstroke diesel)

 

[3930dave]

You'd like to think that a company like JD could have persuaded DD or Cummins to enter the market with their projected sales of GTs and SCUTs.

Some #'s from last Fall:

Compact Tractor Sales Strong in October Across North America | 217-11-14 | Rural Lifestyle Dealer

For a given hp engine range, I don't think any of those USA #'s are high enough (all manufacturers combined) to distract DD or Cummins from their primary large products. (What I do find weird about those tables is how low 4wd sales are vs. 2wd).

Given the hoops off-road manufacturers now have to jump through emission wise, the numbers have to be pretty large to justify a new engine range.

Rgds, D.

 

[Agvg]

They must have got it wrong, and mixed up 2wd vs 4wd.

 

[Agvg]

I don't think any of the classic diesel engine manufacturers are into those small engines, probably they don't want to make cheap engines designed for a relative short life span.

 

[/pine]

Small diesel engines have been in use for a long, long time for marine applications...especially for generators and auxiliary power mills on sailing vessels...many are fresh water cooled using sea water heat exchangers...

It's not uncommon to see "get home" PTO applications that allow an on board generator to be belted or chain linked to the main wheel shaft should the main engine fail...

 

[gary49]

There are a few small Diesel engines that were made here. We have a 3.0kw Onan generator in our boat that is diesel powered (and wow are the parts expensive!). My son has a Case 1835C skid steer with a 40 hp diesel made by Teledyne. I think the big reason small diesels are made overseas is that fuel is relatively cheap here. There's just not as much of a market for Diesel engines in small sizes here, whereas in much of the world the market for Diesel engines that are appropriate for taxis, small trucks and anything else that needs power is vast. We just throw a gas engine in most everything that goes down the road unless it's big enough to really need the torque and economy of Diesel. The Asians had the design and manufacture of small diesels down to such a degree that to this day, compact JD's have Yanmar engines. Caterpillar's small and medium small engines are Perkins', to mention engines from Europe. The Agriculture and Construction equipment industries have been world wide enterprises for decades, I think US tractor manufacturers just couldn't (and can't) see any good reason to design and tool up to compete in this market because they already had excellent choices they could buy and install in their equipment.

 

[LouNY]

I'm going to go a different direction then most here;
our diesels where mainly made for trucking, agriculture and construction starting in the late fifties.
Our tractors where replacing horse teams, and we used horsepower as a selling point, as it enabled larger equipment
and more efficiency. Our trucks already had large gasoline engines and those diesels where developed to haul more, faster,
and with less fuel.
When you look overseas there especially the far east there "tractors" two wheel walk behinds where replacing human manual
labor or a single ox or water buffalo in very small fields and often terraced plots so they developed the smaller engines needed for
there equipment, they also didn't have the large road infrastructure that we do and didn't travel at the speed we do.
A considerable difference in application and driving need during the development period of the tractor and it's engine.
When the small tractor started attracting attention in this country it was the foreign manufactures that had the expertise and equipment.

 

[Mike Madison]

There are some new (USA) diesel technologies in development. Achates engines (Michigan) makes a two-stroke, opposing-piston diesel. This has 3 cylinders and 6 pistons (2 in each cylinder), two crankshafts, and no head. About 30% more fuel efficient than a traditional four-stroke diesel of the same horsepower, and also has very low emissions. On the question of overseas diesels, it's important to remember that those companies have been making diesels for along time, even more than DD or Cummins. Yanmar has been making diesels since 1912.

 

[bunyip]

The old british commer trucks had opposing piston engines back in the 50's but I don't know if they were petrol or diesel.

 

[Agvg]

Its diesel

 

[bunyip]

I doubt as refined as those described by Mike Madison, didn't realise they were a single crank.