Which Is A Rev Happy Engine?

[AlexCim]

generally the less the displacement the more willing for the engine to rev.

if you want something revvy get a rotor.

[ob1]

corolla sportivo motor 2ZZ-GE

will happily rev 8000 all day long

agreed.

Also the G13B from a Swift GTi.

[Mr. Oizo]

generally the less the displacement the more willing for the engine to rev.

if you want something revvy get a rotor.

uhh, no

a 2l 4ycl will be less willing to rev than a 2l 6cyl

[AlexCim]

uhh, no

a 2l 4ycl will be less willing to rev than a 2l 6cyl

Do you have an in depth explanation? Im always looking to learn new things.

[r32line]

Do you have an in depth explanation? Im always looking to learn new things.

Yes please do educate us on why a 2l 4ycl will be less willing to rev than a 2l 6cyl. For that 4 cylinder to drive at 100km/h it will be revving higher, as it accelerates its gearing will mean it will require gear changes more often, it is a smaller engine which mean there is less to spin up, but i guess im wrong. I look forward to seeing why.

[funkymonkey]

you need to get one of them F1 engines... they rev to ungodly RPM's, and they stay there all day too.

[MrAnderson]

how rev happy an engine is has nothing to do with the displacement... its a function of the borexstroke ratio...and to a lessser extent the cam profiles...how reliably it does it comes down to how strong it is. generally a short stroke motor will be more 'rev happy' than a long stroke motor - but it will sacrifice this for torque....

thus the true answer to the question is go and do some research on the bore stroke of all those engines and then look at where on the rev scale they make peak torque and power and also what the rev limiter is set at......

and r32line - the reason for the difference between the 4cyl 2 litre and the 6cyl 2 litre is generally because they have spread the capacity of 2 litres across 6 pistons - and chosen to keep the stroke short - compared to the 4cyl its (prob) a very different borexstrok ratio...

ps ... also changing the gearing ratio will effect things allot.... an old trick is to drop in a shorter ratio box, while you lose some top spead you have better acceleration and a somewhat 'revier' car to drive

Edited September 5, 2006 by MrAnderson

[Revhead]

^^^ what he said

Also, apart from the short stroke, bike engines rev hard because of a low reciprocating mass and the fact that all the mass is very close to the crank, eg the flywheel is small and the clutch is several small plates rather than fewer large plates. I can't remember the technical term for it ><... moment of inertia?? Can't remember but I'm sure someone will

Anyway, find and engine that doesn't have much weight to spin up, a short stroke (as mentioned already) and where all the mass is fairly central and you'll end up with a rev-happy engine. In my understanding the short stroke and having a stroke much shorter than the bore width makes it peaky (ie you need to rev the engine to make good power), and the rest makes it happy to do so.