Bore and Stroke, What is it? Options

[Wishful3S-GTE]

Hey guys, this may be kinda dumb to some of you, but could someone please try and explain what bore and stroke signify. I hate reading things and then somethin like bore and stroke comes up and ruins the whole article cause I don't get it. Someone clarify please? Help would be appreciated.

[GeEkBoY]

10:1 would create more power than an 8.5 in NA (naturally aspirated) form. Turbos are another thing. If you had 8.5 turbo motor turboed at 10 psi (atmospheric pressure is 15 psi) you would be putting in 8.5 x (10+15)/15 = 14.1
note that this is assuming 100% efficiency which is not the case and this is merely an approximation. It would be lower than 14:1, but much higher than 10:1, but the most important part is that there is more air and fuel in the combustion chamber than in the NA setup.

there are 2 primary ways to increase power, get more air and fuel in the combustion chamber or to increase the compression ratio.

by turning up the boost (increasing psi) you increase power by adding for air and fuel as opposed to increasing the compression ratio. The reason they lower the compression ratios in turbo engines is because engines will blow up under too much pressure. If you lower the compression and turn up the boost, you will get more power (and kill your gass mileage btw) without blowing up your engine. If your have been following the guys trying to turbo the 2zz in the new celica and matrix, many people have blown the engines. To turbo a 11.5:1 comp ratio engine is very tricky and not that smart. If they drop the comp ration, they should be able to turbo without blowing the engine.