The Expected Future of Piston Engines
The big stories in the news are about advanced hybrids of who knows how many varieties each with its own acronym and electric cars of similarly varied descriptions. There seems to be a bewildering number of strategies amounting to at least one for every manufacturer. Step back for a second, give them all a big whoopee, and let’s move on. These cars pretty much have the driving adrenaline of a well tuned toaster. Even the best of them pretty much spell the end for those of us old enough to have actually driven anything elemental enough that you felt like part of the machine as opposed to the operator of a synthetic, electronically optimized conveyance device.
The piston engine is a machine that converts longitudinal into rotational motion. As a result there’s almost always some kind of hum, vibration, shake, rattle or roll associated, depending on whether the engine is say, Japanese one the one hand, or perhaps Russian on the other. Most of these feelings are transmitted through the structure of the chassis and are often sympathetic to someone out there, and that’s exactly how we all have our own favorite cars. We all love the buzz. It can be the delicate, high tech feel through the steering wheel of a BMW M5, or the rough tractor-like feel of a bored out Triumph TR3. It matters little what it is, only that we like the way it is. This feel changes with vintage and with model as well. The modern direct gasoline injected cars which squirt pressurized and atomized fuel directly into the combustion chamber at the appropriate time are an entire decade’s worth of smooth beyond the older port-injected models, for instance.
Another modern feature of note is the disappearance of the ignition distributor and the appearance of a separate coil for each cylinder. This scheme effectively isolates each cylinder from its neighbors, which turns out to be a good idea. Like snowflakes falling from the sky, each combustion event is unique, certainly owing its individual DNA to the previous cycle in the same hole, but different in finite ways from the events both previous and of its neighbors. The individual electronic ignition systems have a very rapid response, treating each spark and combustion event as singular entity, thereby permitting a vast array to tuning freedom not previously available. This is a particularly useful tool for increasing power and decreasing emissions.
Those of us still remaining here and awake will note that although exhaust gas recirculation is not as common a feature as it was at one time, its very useful for reducing the production of the oxides of nitrogen in large engines. Air pumps are probably not gone yet either, while both EGR and air pumps tend to be quite a bit more reliable that they ever were before. Similarly, the evaporative (read: gaseous hydrocarbons) filter canister will be with us for a while yet in order to capture the boil-off during the refueling process if not the fuel tank vapors.
In the future we’ll begin to see the electric motor from the hybrid car integrated with the alternator and placed behind the engine where the flywheel goes. It’ll do the same job as a flywheel, smoothing over the power pulses, but eliminating the alternator and effectively making all cars into hybrids. This is very good for the average manufacturers contribution to the Corporate Average Fuel Economy (CAFÉ) target which they are meet. Thus equipped, car engines will become operational in the stop/start mode, both as a result of and in conjunction with the alternator, in order to fill in for the electric motor where necessary. This is much like but not identical to the current Toyota Prius in theory.
Further, modern engines will be able to employ completely operational, and hopefully even robust electronic valve operation permitting completely autonomous control of each cylinder’s valves tied to the ignition as if each was it’s own independent one-cylinder engine, in a train with other one-cylinder engines, all with the same overall operational parameters. The result of this, after another decade of experimentation and cribbing, will be the ability of the engine to actually switch running cycles from 4-stroke cycle to 2-stroke cycle as well as from spark ignition to diesel and other in-between derivative cycles. This, in turn will permit fairly large increases in both fuel economy and power. But even more importantly this will for the first time, allow the engine to be substantially downsized when used in conjunction with supercharging, turbocharging, or both. There are lots of seriously exciting things coming up although the days of manually controlling them let alone actually feeling them working is probably about over now. For that reason if no other it’s probably a good idea not to get rid of your old car just yet, so long as you still like it. The new cars, although vastly more technically advanced and even robust in their own way, will almost certainly reach the finite end of their life and not even be remotely repairable at that point. You’ll than be in the familiar position of getting rid of the current ride and shopping for a replacement as opposed to dumping the huge repair costs into the sinking value of the car. This is pretty much exactly what the finance companies want, and so we’ll have our new car alright, and we’ll have them exactly where they want us.