Periodically, you've been exposed to some notions in this column that were linked to an engine's individual cylinder tuning or optimization. In some instances, we've hinted about certain ideas while at other times more specific information has been shared. Those of us who have spent any time on a farm might say we've managed to "plow up a snake" on the subject, and we felt it might be time to delve a bit further into the subject, if for no other reason than there is clear merit to and benefits from this approach. Now, let's provide a bit of background.
In the early 1970s, Edelbrock introduced a small-block Chevrolet intake manifold design that was unlike any previous concept for a V-type engine. They called it the "Tarantula" and it amounted to a single-cavity (plenum) manifold with runners that all connected directly between intake ports and the plenum. For reasons not important here, the design incorporated four runners measurably shorter than the remaining four. From an intake manifold "tuning" perspective, those skilled in the art/science know this factored into where torque boosts occurred in the engine's overall rpm range. That design changed the landscape among V-type street performance and racing intake manifolds. It also introduced some "flaws" that could be considered opportunities for how engine packages are power-optimized. Specifically, it suggested there should be ways an engine's individual cylinders could be optimized for power (particularly torque).
In 1988, Edelbrock obtained a U.S. patent that focused on linking the power output influence of intake and exhaust passage dimensions to specific ranges of engine speed and introduced the possibility of how valve timing played into the engine performance equation. In fact, and concurrent to that period, there was direct OEM involvement with certain NASCAR Cup teams to zero in on how this type of engine could benefit from single-cylinder optimization. At that stage, there was a measure of camshaft exploration capitalizing on the performance of the type of intake manifolds just described. Even ignition system modifications were employed for further benefits.
The point in recapping these events is to support the idea that treating individual cylinders as engines unto themselves is neither new nor snake oil. While intake manifold designs applicable to circle track engines have continued to improve and are on the threshold of including the "folded hands" concept found in many EFI induction systems, the notion of single-cylinder power optimization continues to emerge with obvious benefits to circle track racers.
Not to the exclusion of engines using common-plenum induction systems and collected exhaust headers, those fitted with individual runner fuel injectors and exhaust pipes are less complicated to apply this technology. Such engines are void of tuning interferences that result from intake and exhaust flow "cross talk" from pressure pulses and related dynamic disturbances common to plenum chambers and exhaust collectors.
If you don't think pressure excursions exist in an engine's plenum-type intake manifold, I recall during a particular engine dyno test when an intake valve head in a 351C Ford racing engine's No. 2 cylinder broke off and wound up embedded in the crown of piston No. 7. But even given these type of reversion pressure pulses, it's possible to improve net engine output by studying individual cylinder performance.