My caged lower pulley project

[cozmo2806]

Probably get plenty of people willing to be the test mule lol.

Haha true, I'm trying to get a friend locally to do it.

Sam,

Any chance I can get you to measure the gap between your lower pulley and the idler? Thanks

Yes I will tomorrow. I dont have a caliper at home where the pulley is.

 

[dougward1960]

hey you could make me one and then i could test it i have an extra 8 rib crank pulley

 

[cozmo2806]

Probably get plenty of people willing to be the test mule lol.

Sam,

Any chance I can get you to measure the gap between your lower pulley and the idler? Thanks

Mike, it looks like the gap between the 2 is .315"
Hope this helps.

 

[cj428mach]

Mike, it looks like the gap between the 2 is .315"
Hope this helps.

It does, now I know what I'll have with the 8.6" pulley I'm having built.

What diameter idler is it? 76mm?

 

[cozmo2806]

It does, now I know what I'll have with the 8.6" pulley I'm having built.

What diameter idler is it? 76mm?

Yes it is the 76mm idler from metco.

 

[lescok]

Very nice stuff OP

 

[MalcolmV8]

How heavy is that outer ring you put on OP? It looks like your lower could have a lot of rotating mass?

 

[cozmo2806]

How heavy is that outer ring you put on OP? It looks like your lower could have a lot of rotating mass?

Yes it is about 2lbs. I am a little concerned about that myself. Not sure what the effects will be just yet. Any ideas?

 

[MalcolmV8]

Yes it is about 2lbs. I am a little concerned about that myself. Not sure what the effects will be just yet. Any ideas?

Could you machine slots or drill holes through the side all the way around? to drop material? Or is it to think to where you're risking structural integrity?

It shouldn't hurt the crank any because that weight just rides on the cage'd bearing. Essentially the motor will just feel it as blower load it has to turn over. It should just make RPMs wrap up and down slower. Just like when you go from a heavy flywheel to a lightweight one you can tell the RPMs wrap up much quicker. You'll have just the opposite.

I wouldn't think 2 lbs would be very noticeable if at all. Earlier this summer I changed out the dual mass heavy flywheel on my 911 to a single mass GT3RS setup which shaved off 11 lbs. That was very noticeable. The car feels more energetic and accelerates quicker but we're talking 11 lbs not 2.

 

[cozmo2806]

Could you machine slots or drill holes through the side all the way around? to drop material? Or is it to think to where you're risking structural integrity?

It shouldn't hurt the crank any because that weight just rides on the cage'd bearing. Essentially the motor will just feel it as blower load it has to turn over. It should just make RPMs wrap up and down slower. Just like when you go from a heavy flywheel to a lightweight one you can tell the RPMs wrap up much quicker. You'll have just the opposite.

I wouldn't think 2 lbs would be very noticeable if at all. Earlier this summer I changed out the dual mass heavy flywheel on my 911 to a single mass GT3RS setup which shaved off 11 lbs. That was very noticeable. The car feels more energetic and accelerates quicker but we're talking 11 lbs not 2.

Yes, I agree with you. Its shouldn't hurt anything structurally I wouldn't think. Just not sure its worth the effort to try and lighten. It would be a good bit of work and there isn't a whole lot to be gained. Probably be lucky to get a quarter pound out of it.

Yea I dont think 2 lbs will be very noticeable. Time will tell.

 

[MalcolmV8]

Yeah give it ago. Probably work just fine.