RUFFLING the feathers of motorsports tradition

[Sam Parkinson]

Going to start this off setting up a scenario which will govern the argument I want to make here.

So you have your Dodge Ram 4x4 mudder truck with a 360V-8 that your currently testing on a chassis dynamometer under controlled conditions . It's a pre-magnum engine and has a carburetor. Lets say it has 195 Maximum horsepower at 4600 rpm and the engine is in overall real good shape running on 93 octane. There is no detonation at any rpm over the powerband. Your testing the truck with it in 2 wheel drive through the transfer case to the dyno rollers at the rear wheels. For the purposes of this scenario the weather conditions and barometric pressure are irrelevant as I'm specifying that they are the same in both scenarios.

You receive a big displacement kit for the motor for Christmas because you've been a good boy or girl. Lets say for the sake of argument that instead of a 360 it's now a 408 cubic inch motor and has both a bigger bore and longer stroke. Since you didn't want to run expensive gasoline at your mudding and pulling events you modified the tops of the pistons shorter but the same exact shape as the stock pistons . You made them short enough that when you go through the static-compression-ratio calculations the new stroker motor has the EXACT static ratio as the before 360 cubic engine had. The balance of the new rotating assembly is comparable to the littler engines balance. The stroker motor has no more windage loss in the crankcase than the smaller motor. Everything in the induction system from the carburetor down to where the heads bolt on top of the block is IDENTICAL to the smaller motor. same valves and camshaft. For sake of this discussion lets say that the stroker motor DOESN'T receive any benefit of better air flow into the cylinder because the bore is a trifle bigger than the littler engine which might cause less shrouding of the intake valves.

Here's my question: You start dynoing this bigger motor running it from high to low rpm looking for how much, and at what rpm the new horsepower reading is. Even though it may be at a different rpm than the 4600 rpm the littler motor made its max. horsepower at; WHAT MAXIMUM HORSPOWER WILL THE STROKER ENGINE MAKE AS COMPARED WITH THE LITTLER ENGINE????. Worry about max torque later.....someone first tell me how much more horsepower we will have ???