well, first off, let me just quote Wikipedia. everyone here is probably familiar with this article....
Beginning in the 1997 model year, the 2.2 liter engine for 1997 Legacy and Impreza models had internal and external changes that yield an approximately 10% increase in power and 3% increase in fuel economy. Accomplishing this involves many factors, one of which is engine friction reduction. The pistons were coated with molybdenum to reduce friction. The thin coating reduces moving friction and reduces cylinder wall scuffing. The piston skirt was reshaped and the piston weight was reduced by approximately 100 grams. Compression ratio was increased to 9.7:1 by reshaping the piston crown. This eliminates the clearance that was available between the piston at TDC and the fully opened valve. Piston pin offset has been changed to 0.5mm (0.002 in). Piston to cylinder wall clearance has been reduced by increasing the piston diameter.
so, my question is fairly obvious.
CAN I BENEFIT FROM THAT UPGRADE, with an ej18, rather than an ej22? having like <rough guesstimate> 125 hp at 5600rm, instead of 110hp at 6000rpm, and 120 trq at 3600rpm, instead of 114 trq at 4200rpm, sounds like a NICE upgrade.
⦁ Displacement: 1820 cc
⦁ Bore: 87.9 mm
⦁ Stroke: 75.0 mm
⦁ Compression Ratio: 9.5:1 - 9.7:1
⦁ Valvetrain: ⦁ SOHC
⦁ Fuel Delivery single point fuel injection
⦁ Horsepower: 110 PS (81 kW; 108 bhp) @ 6000 rpm
⦁ Torque: 149.1 N·m (110 lb·ft) @ 3200 rpm
⦁ Horsepower: 115 PS (85 kW; 113 bhp) @ 6000 rpm
⦁ Torque: 154.0 N·m (114 lb·ft) @ 4500 rpm
⦁ Horsepower: 120 PS (88 kW; 118 bhp) @ 5600 rpm
⦁ Torque: 163.8 N·m (121 lb·ft) @ 3600 rpm
Horsepower: 73 bhp (54 kW; 74 PS) at 4,800 rpm
Torque: 94 lb·ft (127 N·m) at 2,400 rpm
why does the old, primitive, simple basic EA engine make so much torque at 2,400rpm, but it takes the <relatively> advanced and much more complex EJ18 4500 rpm just to get 114 lbs of torque? what is the difference? is it simply because of timing chains and overhead cams, versus pushrods?
or because the ea81 has a 92mm bore, and only a 67mm stroke, versus the ej18 88mm bore and 75mm stroke? I know that bore vs stroke affects torque. is that it?