Rise of the Compact Diesel Engine


Once a novelty, we now rely upon these engines to power many of our landscape machines. By John Fischer

Packed away in shipping containers, well protected and ready for the journey across the seas, compact diesel engines began making their way to the United States from England, Germany, Italy and Japan.

Challenges awaited them. The United States was already well populated with a wide range of gasoline engines that were doing just fine, thank you. They powered early versions of skid-steer loaders and almost all of the products used in the burgeoning turf industry. What was the need for engines fueled by that odd diesel fuel? Smelly to handle and smoky once it was burned -as evidenced by some of the older diesel cars (mostly of German make) on our highways. And, of course, GM’s disastrous foray into diesel-powered automobiles in the early 1980s didn’t help its image either.

Even so, some early applications had been identified and the advantages of small diesel engines were becoming known to the early faithful. One significant one being for truck refrigeration units-a good match of a common need for the same fuel with the truck engine and the ability of the littler engine to run contentedly for many hours to keep its precious cargo comfortable.

From whence they came

There were a number of countries that had an innate need for these engines. The Europeans in general relied on diesel fuel much more so than the United States. Countries-in particular, England, Germany and Italy-produced many of them for such things as agricultural tractors and small construction equipment, but also as power sources for general requirements. On the other side of the world, the Japanese had their compact tractors serving as the primary tool on their many small family farms. It turned out these small diesel-powered tractors, good enough for full scale operations on small Japanese farms, began finding favor in North America as second or “hobby” tractors. Contractors began finding many uses for them, as well.

Realizing the benefits

The little engines of these machines were up to the challenges of successful adoption in their new homes. The loader buckets that quickly became a primary accessory needed hydraulics for operation and the engines provided a range of locations for fitting a nice sized pump. PTO (power take-off) points were generally available at both the front and rear of the crankshaft as well as both the front and rear of the camshaft. This was certainly a welcome opportunity to take advantage of this different sort of engine.

Some of the other technical benefits of these compact diesel engines were starting to be understood as well. Of course their construction was very substantial overall. It had to be to withstand the higher combustion pressure of igniting diesel fuel. And the owners of any and all such engines were pleasantly learning about the reduced maintenance needs-no spark plugs or ignition system. Keep up a steady supply of fuel, change the oil when required, and they keep working away.

But what about the challenges of introducing these engines to a broader range of customers and users who would need to pay more for these nice benefits? Could or would they be more than a niche product? Would the United States in fact open the gates, so to speak, and welcome an influx of them? What about the commercial sales challenges? After all, many of the names of the suppliers of these engines were unknown, (foreign in fact) and the American consumer can be quite discerning when it comes to adopting new things, especially when ones livelihood depends on doing so. Could North Americans be convinced?

Truly unique products

The origins of the skid-steer loader in the United States perhaps dictated that it would be fitted initially with a gasoline engine. Certainly, the simplicity of the first units didn’t require too much in the way of a sophisticated power unit.

But a challenge is a challenge, and if the skid-steer loader was to grow and develop into something more than a specialized machine-which it of course has done-it perhaps needed a little help. This it received from the compact diesel engines that the numerous skid-steer manufacturing companies started fitting.

It might be helpful to note at this point that for a compact tractor these engines are typically a structural element, meaning the engine is strong enough that transmissions and major components can be bolted directly to it. Therefore, it’s quite a robust product to start with.

And another important characteristic of diesel engines of any size is of course the considerable torque they produce. Gobs of it in fact. Also, recalling the prior point made about the multiple PTO points, it might be quite clear to see why these foreign engines were a natural match for the American skid-steer units. The versatility that would in time be achieved for a skid-steer unit could be achieved with the help of these strong and versatile engines.

The typical commercial needs of branding and name recognition of these foreign-named engines did not necessarily surface as they were buried somewhere behind the big access panel of the complete products of well-recognizable manufacturers. If the engine is fed fuel and gets an oil change on a regular basis it just runs and runs and I don’t need to worry about it at all!

The fact is this that wasn’t uncommon for the owner of a skid-steer loader or other diesel-fueled unit to not even know the manufacturer of the engine in a their particular unit. It was enough it was one of those sweet little foreign diesels. From an operational standpoint, that was just fine. But in a perverse sort of way, this was not so good for the engine manufacturer, as it’s not apparent that his product is doing all that work day after day.

Long term, however, we know what’s happened. The versatility of compact diesel engines has increased the versatility and applications for skid-steers. Any early concerns about relying on a compact diesel engine for making a living are no longer concerns at all.

Appreciation grows

While being used in a skid-steer is a noble aspiration for a compact diesel engine, perhaps there’s another volume application that is just as important and perhaps not quite so strenuous? The early adoption of these engines for turf equipment is certainly worth mentioning.

Just as compact diesel engines have been important as the sales of skidsteers have grown, so have they been there as the development of turf equipment has grown.

While not needing to have all kinds of accessories and other accouterments hanging off of them-after all the basic needs of a turf machine are to spin the blades and scoot about in a quick and effective manner-some of the key benefits of diesel engines are of equal importance.

At the top of that list is low fuel consumption and their durability, a wonderful attribute for cranking out production day after day. And, we can’t forget torque, lots of torque.

And a great match and partnership has developed with the sweet-both in performance and sound-hydrostatic transmissions that were fitted on the turf machines and evolving quickly. In a similar coy manner, buried in the machine and not readily known by name as they diligently completed their work every day.

Today’s challenges

Having met these early challenges of pricing and market acceptance and customer comfort with diesel fuel, things have been quite comfortable for some years. Container after container of engines carefully packed and on the dock, and then shipped continue to find applications in compact equipment, such as skid-steers, track loaders and lots of other products.

Sales people now more comfortable and knowledgeable in explaining the benefits of a diesel engine. Service people are now experts on how these little engines work and how to repair them. Customers are just as glad that they’re here and are confident they’ll continue the power for day after day of production.

And even when the supplier of the engine for a particular product might still remain unknown, the fact that it’s a compact diesel engine is reassuring enough.

But what’s come along in recent years, of course, is the realization by EPA and such organizations in particular that these little engines do in fact produce some unwanted emissions. Specifically for diesels, particulates (smoke), which we remember can be seen, and NOx, which is not visible but is just as undesirable. And, due to their success (remember they’ve been coming to the United States for years now), there’s quite a few of them and therefore a considerable contribution to the overall emissions inventory. If this was not the case, the EPA wouldn’t worry so much about them.

But the good news is that these and other diesel engines have been up to the challenges of meeting the emissions regulations.

Have the engines become to be a little more sophisticated with the addition of such things as electronics and turbochargers and even aftertreatment systems such as SCR? Yes, that’s the case.

But have they also improved with the addition of some of these items that in addition to reducing emissions also increase performance and efficiency? That’s another nice development.

But we now know that compact diesel engines-having proven their resilience and ability to meet the many challenges continually thrown their way-are here to stay.