please Help! JDM engine differences..

Originally posted by AzCivic
well if your replacing a blown engine then never mind the turbo d16 idea, BUT where did you learn that only the stroke of an engine determines the torque output!?!?!!? All you're doing when you stroke an engine is increasing the displacement of the cylinders(by having the pistons move up and down more), which is the same thing boring out the engine(except the increase in displacement is outward from the center of the piston) either way you have more displacement and more room for air/fuel, meaning more power(torque), which should end up being about 120ftlbs in a d16z6, which is limited by the head design and compression ratio.

First of all I am a Jet engine Technician, and I was about half way through my automechanics certification (about 6 years ago before I stopped taking my classes). I do tend to know a few things about this. Think about it for a minute. According to u all 1.8 liter engines should all make the same torque and horsepower output as long as the compression, cam specs, head design, and everything else is generally the same. Unfotunately this couldnt be farther from the truth. Or ask yourself why dont they just make an engine for the street that is all bore, and has a terribly tiny little stroke to it? The reason is the car would not make any torque, it wouldnt be streetable. There is a reson why the dimensions of an engine matter. It does matter about the stroke length and the bore. Its all about engine design and physics. Think of the Formula 1 cars, or the indy cars. Look at their dimensions. They have almost no stroke and large bores, why do u think that is? Look at their displacement and tell me that they make relatively good torque figures compared to their HP, or make equal torque figures equal to that of other race engines (of the same displacement). They dont. There is a huge difference. I have taken so many physics classes that it makes me sick. These are basic engine design physics. I could go into it in more depth with the theories but I think u and I would fall asleep (its a very long theory, and I would have to look it up in my books). I know where u are going with your train of thought. I once thought the same thing. In your mind it makes sense, but unfortunately physics dont always make sense. Trust me on this.