JE Pistons has been in the trenches since the beginning of the import revolution and has been able to develop different designs to better the combustion efficiency of a Honda engine, whether the application is boosted or all natural. Just like Crower's list of racers, all the top racers are or have at one time ran JE pistons in their race engines.
The Theories
One of the biggest controversies in engine building is deciding to go with a long-rod or short-rod engine. Extending the rod will benefit those who believe in bigger stroke with more torque and low-end power.
The short-rod approach creates high-rpm engines with fast piston speeds that mainly rely on peak horsepower with the engine revved in its sweet spot most of the time. We plan to build both styles on these pages documenting the differences as we go along. In their final form, each engine will be dyno tested to illustrate the difference in how-or more, precisely, where-in the powerband each makes its impact felt.
In a stroked deck-plate application, an engine is not only stroked via crankshaft, its rod ratio is also changed by lengthening the rod's center-to-center measurement, extending the deck height as well as installing taller sleeves. On our B18A engine, we not only have an advantage of a taller deck height to begin with over the B16A, we will also add an additional 25mm to the deck. This in conjunction with a billet 95mm Crower crank gives us a rod ratio of 1.63 and a center-to-center rod length of 154.94mm. This approach theoretically results in an engine that will produce more bottom- to mid-range torque while also slowing the piston speed. The advantages of this route are more bottom-end power and more displacement with some loss on the top end and a coinciding reduction of heat caused by friction. This helps maintain durability.
With the short-rod engine, we not only start with a short-deck engine block, we modify it for a GS-R stroke, which changes the rod length to 132mm for a resulting 1.32 rod ratio. The theory behind this engine is that all the horsepower will be realized in the top-end of the powerband. This means the engine will have to always be turning high rpms to effectively propel the car down the quarter mile.
Theoretically, the advantage of this engine is that it should produce more top-end power, but will not make as much in the mid range as the long-rod engine. The disadvantage centers around torque and whether the short-rod engine will generate enough to pull the weight of the vehicle from a standstill. Considering most sanctioning bodies have a 1,600-lb minimum weight requirement, the engine should technically build enough to launch a race car. Street cars may or may not be a different story.
The Engines
When comparing the engines, there are many different variables that can have an effect on their powerbands. Keep in mind our main objective is to figure out the difference between a short-rod and a long-rod engine. This is not to determine which is better; that is decided by the type of car and the expectations of the car that the said engine is installed in.
Figuring out a cylinder head was the most difficult part of this story. Since there are also many variables involved in determining the cylinder head and valvetrain characteristics, we have decided to keep things neutral by sticking with the same specs for each engine. A GSR ported head for both will be used but eventually we will play with the cam profiles to maximize potential. The accompanying spec boxes outline the hard parts of each engine and the accompanying Round Table sheds light on the concepts and preferences of each engine. The Round Table is hosted by Turbo's Gary Castillo and features enthusiastic input from Brian Crower, Bill Craddock and Dan Benson.