help - spline issue on dyno setup

[hopkid]

We have become stumped on how to secure a sprocket on our dyno shaft. We are running a chain to a seperate shaft to power the dyno, this will allow us to change the gearing to power the dyno within it's operating range.

Does anyone have any information/ideas on how to secure the sprocket to this shaft? We do not have the ability to cut splines in our machine shop, but we could send it out. We are running a 2004 R6; I'm not even sure how to figure out the type/dimension of the spline. There must be some common types used for motorcycles. I'd rather not key or machine the sprockets at all so we can reuse them. Pictures would be nice. Thanks.

-Dave

[hopkid]

We have become stumped on how to secure a sprocket on our dyno shaft. We are running a chain to a seperate shaft to power the dyno, this will allow us to change the gearing to power the dyno within it's operating range.

Does anyone have any information/ideas on how to secure the sprocket to this shaft? We do not have the ability to cut splines in our machine shop, but we could send it out. We are running a 2004 R6; I'm not even sure how to figure out the type/dimension of the spline. There must be some common types used for motorcycles. I'd rather not key or machine the sprockets at all so we can reuse them. Pictures would be nice. Thanks.

-Dave

[drivetrainUW-Platt]

possibly get a junk engine and pull the splines shaft straight out of the engine...or you can use any gear from any bike with the same chain number.

[RickyRacer]

Are you trying to change the gearing on the engine outut shaft or on the dyno shaft? We took a sprocket off of our old engine and welded it to a steel sleeve. Our dyno shaft was splined for a chevy clutch so we found a crap clutch disc and machined off all of the material but the splined area and welded it to the other side of the shaft. Al was done on the lathe to keep it concentric. Hope this helps.
Rick
Long Beach State Motorsports

[hopkid]

The issue is securing a bike sprocket to the shaft that is coupled w/ the dyno. This way we can run a chain between the two, and simply swap gears to change the gearing. We don't have abundant sprockets to use so I was trying to come up with a non-destructive way of mounting a sprocket to the dyno shaft. I'm think about just taking measurements as close to possible off the R6 output shaft and seeing if anyone will cut some splines for us. Thanks for the help so far... anyone else?

[Akos]

hopkid,

I would not try to drive a dyno through a chain as you are sugesting. Usually you end up with small sprockets on both engine and dyno and a short length of chain between the two.

Speaking from experience, with this type of setup, you will overheat this chain and cause it to glow dull red, before flying off the motor.

I would suggest you direct couple the dyno to the motor's output sprocket though a double chain coupler. If your dyno can't handle the motors torque, bet a bigger one. It will be cheaper than either a gear or belt drive that will hold up.

The easiest way to put a sprocket on the dyno, is to have its shaft keyed and than get the appropriate sized industrial sprocket. The 520/525 engine sprocket common on most bike engines has the same pitch as a #50 industrial sprocket.

Cheers,

Akos

[Bogan]

Hi Hopkid,

We had a similar problem a couple of years ago, we used a chain drive on our dyno as it was the cheapest way to do it at the time. We used an old 16 tooth sprocket on our custom made dyno shaft with 3 tapped holes in it. The shaft had a spigot that the sprocket splines located snugly on, and we drilled 3 holes that were spotfaced through the sprocket. We used 3 M8 bolts to hold it. We ran a very short chain. I'm not sure what you mean by running different sprockets for the dyno operating range. We just used the appropriate gear to get the right speed. I will try to dig up some photos for you. Good luck.

[hopkid]

Akos, thanks.

#50 industrial sprocket.. got it. I will keep my eye out for overheating the chain, we shall have to see. The reason I don't want to direct couple it is because even in sixth gear our dyno does not have the same 'bandwidth' as our R6 motor in the rpm range. By using another set of 'gears' or sprockets in this case, we can properly use the dyno for a few selected operating ranges to ultimately map the entire engine rpm range.

Bogan,
I would love some pictures. Sounds like you basically made a flange plate to bolt up to. How did it hold up? Did you have any problems w/ the chain overheating?

[LCP_KL]

i suggest running the dyno straight off the output shaft of the engine. i made a homemade dyno once using a hydraulic pump pumping fluid through a high resistance circuit and a load valve. the pump was connected to the engine through a CV joint. saves on having to align rotation axis. and the dyno and engine shaft will also not have any resultant sideways force during running, saves on fatigue.

i took a 2+ in bar stock. parted it off to 16mm thickness, made an internal spline on the inside and on the outside, have a 6 bolt PCD to mount to another adaptor which in turn mounts to the CV. oh yes, it was connected to a CBR600 and a GSXR600 during its life. can post pics if you want.

KL
singapore

[hopkid]

LCP.. just exactly how did you make internal and external splines? Please post pics... it saves lots of typing.

[LCP_KL]

we go to a shop that has the spline cutter mill, mount it on a turntable and the cutter will do the job. how we get the pitch? well, we bring the original bike engine's sprocket (which is splined) and try to fit different cutter bits until we find the correct size. then its a matter of mount and cut.

can i have your e-mail add? send you a collection of photos. otherwise, its hard to show if i post.

[Micko..]

hey hopkid,

in 04 we ran a 03 R6 and tuned it on an old fraug waterbrake dyno. we used a shaft that was turned up with a bolt pcd that mached the dyno and a spigot that mached the internal spline diameter of the sprocket. and we just bolted the sprocket to the shaft (just like bogan said) we were running extreemly short chain and a 16 tooth sprocket, we didn't experiance any of the chain heating issues that akos mentioned either. hope this helps

cheers
miko

[LCP_KL]

sent you an attachment yesterday Hopkid. wonder if you recieved it. forget about using the chain. additional pt of weakness when you pulling 70+ hp at 10000rpm with the engine screaming... haha.

[Bogan]

Hi Hokid,

I am curious to know what the operating range of your dyno is? If you use 2nd gear and rev the engine to 14000rpm, this equates to a dyno (output) shaft speed of around 3500rpm, this includes the primary reduction of app. 2:1 and gear reduction of app. 2:1. We used a chain drive 16 teeth on the output 16 teeth on the dyno and did all of our testing in 2nd gear. We had no issues at all with our chain drive system. Still trying to find those pics.

Regards,
Bogan.

[magicweed]

The operating speed of the Land and Sea Dyno we have is from 2000-10000RPM. However, the most accurate readings come from the middle of the curve at around 3500-8500RPM. The removable rear sprocket was to be used to gain the greatest resolution in those areas by swaping the dyno shaft sprocket and using 6th gear to set the load on the engine and tune it. This would give us a lot higher resolution in the lower part of the power band, something that we haven't had in the past. I'm pretty sure the reason for a removable sprocket was to keep us from damaging and having to buy another sprocket for that motor itself. Hope that clears up any questions about the setup.

[hopkid]

Lcp_KL,

I did recieve those photos, thank you. I personally believe the best way to go here is with a chain. I have seen many setups like yours, (direct couple to the dyno), but our dyno does not have the ability to be directly coupled. Also, chains are rated at a much higher hp rating that what we will be seeing.

[Travis Garrison]

Maybe it's been brought up and I missed it but things to consider with chains might be:

What happens as your chain wears? Even if you lube it consistently, it's one more thing preventing you from comparing results from day X to results from day y...as the chain wears out it's going to rob hp

You have to tension a chain, which becomes a royal PITA...and can also lead to inconsistent results.

How can a dyno NOT be compatible with direct drive?..

[Wright D]

Peter D Motor Sports sells a drive shaft adapter for just about every sport bike motor there is. It is a machined aluminum piece that has splines cut in the center that match the sprocket. It will go over your out put shaft, and then you could run a drive shaft (or what ever you like) to your dyno.

We have these parts for our front engine dirt track cars that use motor cycle engines. We turn the engine 90 deg and then run a drive shaft down the length of the car to the diff.
Here is a pic. http://www.peterdmotorsports.com/parts/drivetrain/hm-20-2513_bg.gif
The drive shaft adapter allowed us to run a very short drive shaft from the motor to the dyno, allowing for any small miss alignment, while not robbing power. We can even make you a custom length drive shaft.

We sell all kinds of stuff that fsae teams have found useful. We also offer an fsae discount.

Our web site is
http://www.peterdmotorsports.com/

Our phone number is:
602-716-0212
Ask for Dustin