Changing to a belt

[orangebusa??]

im thinking of it as its initial impact the revs create on the chain or belt which is whats at question hp and torqe is not when you think of an inline four cylinder compared to a twin there is more rotating mass the amount of force actually applied at impact of the engine tranmitting it hp and torqe to the clutch then the chain or belt then the tire and then the ground will be greater of course the clutch takes it first and the clutches job is not at question the next impact, and that may be a poor choice of words,of that higher rpm and rotating mass is the chain or belt the force will be much greater from the busa then a harley regardless of the amount of power each makes. once in motion that force on the chain or belt can be figure in terms of hp and torqe that the engine makes if you rev a motor to 2000 and let the clutch out the tires is going to spin but not as fast and with as much initial force as if you let it out at 4000 think of just one thing say a car that weighs 10000pds hit a line of water barrels at 30mph and a car that weighs 5000 pds hit the barrels at 60mph now granted the 10000pd car is going to drive further before stop but initial impact of the barrels will be higher with the with more speed now think of it this way the busa engine is heavier and faster then the harley hp and torqe aside the impact will be greater from the busa im kinda getting my self confused let me know if you see my point

 

[FLCN72]

orangebusa??

If I am understanding you correctly, you are saying that the Busa will put more initial force on a belt or chain than a v-twin like a Harley. For example, when accelerating quickly or making rapid changes in engine RPMs.

That may be true, given that a Busa will rev higher and faster than a v-twin of similar displacement. But I think the individual power pulses of the engine matter more. And the way that an in-line-four like the Busa makes its power is different than how a v-twin does. And that difference might matter.

For the sake of argument lets say we have two bikes with exactly the same engine displacement; one is a v-twin and the other is an in-line-four (IL4). The IL4 will produce a power pulse every 90 degrees of crankshaft rotation -- or four times per revolution. This makes the rotating mass in the engine somewhat self-balancing, requiring lighter "balancers" inside.

The v-twin will produce only two power pulses in every crankshaft rotation. The individual power pulses will be larger and more violent. And they will not be equally spaced through the crankshaft rotation, as they are in the IL4. Something like: BANG - BANG - pause - pause. This requires a v-twin to have large and heavy counter balancing built in to make the engine vibrations smoother. Which also makes them slower to change engine RPMs.

Ultimately I think the IL4 could be easier on belts than a v-twin. Due to the smoother delivery of power pulses. So long as the belt could handle the peak torque, I think it could handle the less violent (but more frequent) power pulses of the IL4.

 

[RaiderDm]

I hate to repost the same thought but it keeps coming up. Why can a 151ci thug twin motor that produces torque and hp well in excess of the Busa manage a belt and not shred it?

Most engines as you describe them are trailer queens.
Hardly any of them see any "real" use. The are rarely
rev'd to redline while under load. Also their torque curve
is fairly or relatively flat thus placing less strain on the belt.
This is why Metric cruisers with chains require less adjustment
than sport bikes. Sport bike engines rev higher quicker placing
substantially more strain on the belt. Sport bikes also run
through their rev range more often on any given run.
IE they get shifted more. Both up and down.



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[orangebusa??]

actually i was just thinking of the types of things and styles of riding that actually cause chains and belts to snap or break if your letting that clutch fly alot (wheelies,burnouts,and overall agressive riding manners)im gunna say 10000rpms of busa is going to break or shred a belt alot faster then a chain and i dont think a belt would work on a busa unless maybe there is some kind of spring load cushion device at the sprocket off the engine to absorb the impact along with the cusion already in the rear once in motion the belt may work

 

[justintime2]

I love it!