Compression Vs. Torque

[Ninja_Wookie]

Ok I have a question... Does compression ratio have a large effect on torque? And if so is it higher compression higher torque or is it vice versa?

[tienlude]

cant be vice versa DAT has been proven many times, for example most good nissan motors(fourbangers) have mad torque not very high compression--at least not like a honda....but im thinking the other way around works more often than not in that way especially from my own experience, i got cams and pistons swapped and the torque went crzy compared to how it was---this a was on a jspec h22
pistons were 10.5-1 went to 11-1 and type s cams...big huge ginourmous difference in torqaue

[jon]

torque has to do with bore, and stroke. hondas have small bore and small stroke, hence the high end power gains, with a longer stroke you will have more torque, but less rpm. thats one of the reasone all the muscle cars rev out at like 4k.

huge bore+huge stroke = huge torque

small bore+small stroke=high rpm power

[Ninja_Wookie]

So how would you go about changing your bore and stroke

[civic1784]

Originally Posted by BFK_SI_EG

huge bore+huge stroke = huge torque

small bore+small stroke=high rpm power

Big bore + small stroke = high rpm power

You can think of your rods and crank acting like a lever. The further they can be moved, the more work they can do (like a longer lever). The problem with a long stroke and higher RPMs has to do with piston speed. Increasing the stroke will increase piston speed, and that will increase friction, which will cause the engine to operate inefficiently. This isn't a problem if the car isn't driven in it's high RPM range often, but if a car is driven at high RPMs frequently, this can lead to excessive wear and stresses, possibly even failure.

[jon]

yea, i know that, but i was just talking about hondas in general, with the small bore+stroke combo

[civic1784]

hondas = small everything

[jon]

Originally Posted by civic1784

hondas = small everything

except exhaust tips and wings

[civic1784]

Originally Posted by BFK_SI_EG

except exhaust tips and wings

...and egos, don't forget that

[tienlude]

Originally Posted by civic1784

...and egos, don't forget that

hey, now, chill.........













good thread, good info, now its awhole lot clearer for me.

[spray004]

Yes it does. Compression has an affect on both torque and hp. Simply put, the more squeeze you have, the more go you 'll have. Two given engines with the same bore x stroke, but w/ two diff Compression ratios. The higher compression ratio engine will have more torque and hp.

big bore/small bore + small stroke = high rpm
big bore/small bore + big stroke = low rpm

[Ninja_Wookie]

Ok so if a higher compression helps torque how the hell do you raise your comperssion ratio?

Originally Posted by StillStockish

Ok so if a higher compression helps torque how the hell do you raise your comperssion ratio?

DUH! B16, H22 and VTEC, y0!

[spray004]

Originally Posted by StillStockish

Ok so if a higher compression helps torque how the hell do you raise your comperssion ratio?

Increase cylinder volume and/or decrease combustion chamber volume.