One might very well spot, sitting in a remote corner these days, a not-quite-so-familiar large spark-ignited (LSI) engine — in position for various engine power needs. Based on the architecture of a liquid-cooled automotive engine, it might be a little mysterious, its actual origins not always clear.

But it would have come from a solid family of a matching block, cylinder head and all the requisite internal components. Those components include crankshaft and pistons, with connecting rods holding things together and passing power along to the previously mentioned crankshaft. These are all carefully designed and put in place to work together harmoniously for many thousands of hours, just as such basic automotive powertrain packages would have been doing for many thousands of miles. 

From this nice arrangement the LSI engine would have been dressed-out with the necessary heavy-duty components for demanding worksite requirements. Shiny sometimes. But with durability being the more important characteristic in the selection of each of them.

These engines are simple overall, nothing to be nervous about.

Let’s have a more detailed look at these sweet (as in pleasant) offerings, and why one of them might be just what you need for a new power requirement.

The Formative Years

Early utility-type engines were often simply direct carry-overs from the automobile world. It was straightforward to produce a few extra of these on the assembly line as simple power units. Manufacturers would match them with a basic cooling package, offer them up at a relatively low but still profitable price, and make a little extra money.

For machinery that was fairly simple, it was a wonderful pairing. Operationally, it would be simple as well. Fit a basic carburetor and maybe a little larger air cleaner to keep the dirt out, and all the feed requirements were taken care of readily.

Things did change, however, as the engine world matured. Durable and robust diesel engines came along and became more accepted on many products. Strong torque and generally longer life caught the eyes of purchasers. And while the overall and particular engine power needs at many major drill sites still require the guts of a throaty diesel, gasoline products are finding a new home — and not just the smaller ones used for utility (support) purposes. 

“Why is this?” you ask.

Well, would you believe that Environmental Protection Agency (EPA) emissions regulations come into play here? Indeed they do, as will be explained.

That All-Important First Day

It’s quite possible that the business you’re a part of started out with a modest gasoline truck and perhaps a humble, smaller machine driven with a gasoline engine. The primary needs at the time? Something fundamental and low cost, and able to start actually making holes. And money. For a vast range of technical sorts of folks, having a basic understanding of engines from various automobile experiences, this is a straightforward foundation from which to start.

Expanding Horizons

But in recent years rumblings could be heard in the many neighborhoods where reside those involved with equipment requiring engines. Early rumblings first came from the EPA about the need to reduce emissions from these engines. This turned out to be straightforward. Remember that they’re based on automotive engines from companies for which doing this is second nature. Upgrade to electronic fuel injection (EFI) rather than carburetors. Add one of those wondrous three-way catalysts that cleans up the exhaust so effectively. That’s about it. Proper fueling at the front end and proper attention at the back end to clear up the remainders.

But further rumblings were heard all around from engine users all over as the final — as in Tier 4 Final — diesel regulations came into effect. It turns out that cleaning them up properly does take some technology, and such things run into some serious money. Folks started seeing some of the numbers and they started thinking about alternatives.

Well, real world rumblings (actual engine noises) are being heard these days from folks who have found out that an LSI engine can indeed do the work just fine for many applications. In fact, you might have some friendly neighbors who are keen on getting unnecessary trees out of the way by reducing them in size to something more manageable, and it’s not uncommon these days that one of those beastly chippers is fitted with a sizeable gasoline engine. That does the job just fine and is very responsive to changing load needs with an EFI system in place.

Getting One Ready for the Day

And these LSI engines are not that demanding overall. The oil needs are pretty straightforward since the high-volume requirements for automobiles establish easy availability and selections.

Fuel needs are also simple: just the readily available E10, and using it in proper time. The restraints of the small-engine folks for that 30-day usage window are not as strict with an EFI system. And if you’ve got some older stuff in a red can, you can probably use it (up) in one of these without too much concern.

The March to the Present Day

A product using one of these engines still might not be the center of attention on many drill sites, but it could be readily spotted where you just need some simple power. Perhaps you have one running steadily, hour after hour, to supply electricity. Or in a corner somewhere spinning around to drive a pump and smoothly move water to a different location. Or, actually, even puffing away (in that nice sort of “engine” way) to compress air and get it to the required pressure to assist in a drilling operation.

As with any engine, it’s important to remember that they like to be run. Oversizing a product is not good if it means an engine of any sort is running at low loads. Better to have several smaller units available for a particular requirement, and give one of them a break if the workload drops off.

These large gasoline engines, though, are actually a bit more tolerant of partial loads compared to diesels with the latest after-treatment, which is quite dependent on high operating temperatures. Another advantage? An LSI requires no inconvenient regeneration products or other similar needs because gasoline engines just don’t produce particulates the way diesels do. Given that, they do not have particulate filters fitted.

But oh! Have a look around. All these wonderful — sometimes a bit mysterious — engines! We know we can continue to rely on them to put in a full day’s work each and every day we call upon them.