125 HP?

77KZ650 wrote:

Lorcan wrote:

Hopefully you can explain, as we are building a 1000hp bike and I don't want the chain absorbing 60hp. That's a whole engine's worth for some people! :whistle:

1000:woohoo:my 650 only started out with 64:lol:

That wouldnt be that monster turbo big bore GPZ1100 you were thinking about awhile back is it? :evil: :evil: :evil:

were gonna need a bigger boat,and more boost and nitrous captain!:S :evil:

No it's not a Kawi unfortunately. It's a Puma.

Lorcan wrote:

OK, I've read it. I can't see anything there that explains what happens to the 14HP (10 Kilowatts!) my drive chain is absorbing according to your rule of thumb though. Maybe it errr...evaporates?

Hopefully you can explain, as we are building a 1000hp bike and I don't want the chain absorbing 60hp. That's a whole engine's worth for some people! :whistle:

I don't have a clue, but 10kw is an awful lot of power to get rid of as heat.
Glowing chain indeed :woohoo:

Seems like the obvious answer is that drive chain losses are much less than predicted.

Thanks to this thread I'm spending more money than I intended! I ordered a 1075cc overbore kit and .410 cams to complement the 34mm carbs. Cry once and be done with it. The grin factor should dry up the tears.

dont forget to clean up those intake ports a little to match those 34s and a little on the exhuast side so you can get out what goes in;) and some good springs and shim under buckets to go with those cams you bought.

The 15% power loss from crankshaft to rear wheel, 9% from the tranny, and about 6% from the countershaft to the rear wheel, came from Honda and mentioned in a bike magazine several years ago. Could have been Motorcyclist or Sport Rider.

Kevin Cameron says in his Sportbike Performance Handbook, page 73, that "Each mesh of gears, and each chain-drive causes a typical loss of 2-3 percent, so we have a 6-10 percent power loss from engine to the rear wheel."

But losses from the countershaft to the rear wheel can be noteworthy, given the construction, size, and condition of the chain:

RK 530LFO Chain and Vortex Sprockets

A Practical Guide to Chains

First link basically says a bad chain and sprockets can cause a 5% power loss.

Second link is dead.

Lorcan's question still stands.

5% of 100 hp equals 5 hp.
746 watts per hp.
5 hp x 746 watts = 3730 watts

One of the many rules of physics is that energy can be neither created nor destroyed, only transformed.

That's mechanical energy at the chain, and if the chain is transforming it into another type of energy, it can only be heat. And 3730 watts is an awful lot of heat.

For example, at 220 volts that's equal to approximately 17 amps.

In Lorcan's case, 5% 0f 246 hp (if I recall correctly) is 12.3 hp.
12.3 hp x 746 watts = 9175.8 watts.

More than enough to heat my garage on the coldest winter day

... "standard roller chain drives operate at 91 to 94 percent efficiency, depending on the application, so energy costs must be taken into account."

Selecting the right drive system

Chains

An investigation into the selection of optimum chain and sprocket size

Post edited by: BohicaBob, at: 2006/10/07 19:10

BohicaBob wrote:

... "standard roller chain drives operate at 91 to 94 percent efficiency, depending on the application, so energy costs must be taken into account."

Selecting the right drive system

Chains

An investigation into the selection of optimum chain and sprocket size <br><br>Post edited by: BohicaBob, at: 2006/10/07 19:10

you guys are getting way too technical,my head is starting to hurt trying to keep up with you guys!:evil:

BohicaBob, Neither the first nor last link work for me, and the middle one discusses primary chain/belt drive, while (AFAIK) we are discussing final drive chains (and it is even stated in that discussion that the two are different).

I'm still waiting for someone to show me where the 7 Kilowatts of power that Lorcan's chain is supposed to be robbing is going.

So where is 7,000 watts of power going?

caffcruiser wrote:

<br><br>Post edited by: caffcruiser, at: 2006/09/29 09:45

Do that with stock pistons and kiss the ring lands good-bye....you need forged pistons for juice.

energy is power multiplied by time

I doubt Lorcan is running at full output for more than 80 seconds. 800kw-sec is about what it takes to boil 10 cups of water. Heat energy is radiated and when "the chain" is referenced, it's likely the chain, sprockets, and tires.

Friction in the driveline increases with power so the percentage loss will be less at 20hp than at 200.

I would not be surprised it the 5% loss number is correct at full output.

-Duck