Jim Clarke isn’t a household name, even in the automotive circle - yet? He was previously a veteran member of Ford’s engineering team, having a hand in the development of their modular V8 and Duratec V6 engines.
According to Car and Driver, Clarke and his partner, Dick Fotsch, former president of Kohler Engines’ powertrain division and that of Navistar, have filed a patent for an interesting new motor - one that would have a dedicated turbocharger for each cylinder. For example, a normal four-pot would also happen to - abnormally - be quad-turbocharged.
Part of their theory on how this approach would greatly benefit internal combustion includes something called “synergistic induction and turbocharging”. Essentially, and aside from the individual petite turbochargers, it will need two throttle bodies per cylinder - one for each intake port. In tandem, these air induction and extraction system will allow the engine’s cylinders to fill much more quickly, and the resulting hot gasses exiting the chamber will provide a more potent flow to spool the turbines.
“Between the throttle and the intake valves, the typical engine has an intake-manifold volume roughly equivalent to the engine displacement,” Clarke said. “That takes time to fill when you open the throttle. The closer you put a turbocharger to the exhaust valve, the more energy reaches the turbine to accelerate it.”
The smaller turbines, which are generally 20 percent more compact than that found in a conventional single turbo engine, would mean it would require less force to spool, perhaps to the point of being lag-free. But since the induction system isn’t dependent on a large turbine being fed by exhaust gasses from multiple cylinders, the perception is one of virtually instant response.
Despite the idea having quite a lot of potential, a very obvious hurdle would be that of cost as the component number per engine would rise. And as these new parts would be under high stress, the likelihood of something untoward happening increases, especially if the proper amount of care and time isn't taken to fully test and refine the prototypes prior to rollout.
There have been many attempts to squeeze more power from the traditional internal combustion engine, and these have mostly materialised in the form of forced induction. Concurrently, gains in fuel efficiency and reduced emissions have come more gradually by such innovations as direct fuel injection and cylinder deactivation.
One avenue previously explored was the idea of eliminating the pressure vacuum between the throttle body and intake valves. Moving the needle here would greatly improve engine response as well as result in a more complete combustion, reducing fuel consumption in the process.
BMW had implemented its Valvetronic system to good effect, boosting engine response while seeing an uptick in efficiency, essentially keeping the throttle body fully open in nearly all operating circumstances, with the accelerator pedal instead controlling the intake valve lift.
Elsewhere, there are other efforts being undertaken to achieve similar ends. Freevalve, a sister company to boutique supercar outfit Koenigsegg, are close to putting an engine with fewer components - electronically controlled valves and no camshaft(s) - into production, while claiming to increasing power, torque, fuel economy, and exhaust emissions as a bonus.
Mazda, meanwhile, will be launching their new line of SkyActiv-X engines in the next-generation Mazda3 hatch, the first mass produced gasoline engine to use cylinder compression to ignite the air/fuel mixture, rendering the spark plug virtually unnecessary. Of course, they too are claiming this to have impressive plusses on the efficiency and power front (though they did say they are to supplement this with a supercharger).
Looks like the internal combustion engine still has a few more good punches left in it after all.
