4 inch pulley anyone?

[fysty-1]

If I remember with a 4" some spacing is needed just to clear the radiator.

Oakey Doakey. I guess I would have found that out for myself when I attempted to install mine. :yahoo: :smilie_happy:

 

[countryboy843]

ok the time everyones been waiting for

 

[MagnAndy]

Country, If you have any dimension updates by the time you are done or can provide details of the tools you ordered/source, I would like to update my drawing. This way the info will be available in the public domain for future riders.

The photos look good but I wonder if the belt path is too far out - would like to hear from somebody that has done the conversion - I haven't even seen that area on my bike yet.

 

[countryboy843]

im going to pick up an altenator tomorrow or monday and a belt so i can see if i need to trim anything off the pulley or not . so far its just like the drawing and as far as tooling i used carbide rougher and finisher and a carbide forming tool for the ribs , these tools arent really anything that the average person can get and you need the machines to use them with

 

[slabghost]

Spacing looks right to clear the cam belt covers.

 

[dan filipi]

Yep, that's what it looks like with the belt covers off.
Make sure you go all the way installing the covers before making any changes to the dimensions because I think you'll find you might actually need more spacer.

It doesn't look like you have the front washer on the crank. That should be drilled so it can go back on because it keeps the belt running on the crank.

 

[countryboy843]

yah still have to trim the cam washer , cut the covers and im going to trim the back of the new pulley to help clear cover bolt

 

[MagnAndy]

Going forward, why not insure 'the washer' isn't left off by incorporating it into the pulley? You have to hogg the material off anyway - leave some on to form the washer and it can never be left off! It is also better mechanically than a stack of rotating parts held in place by a bolt. If you can provide the OD, thickness and location up the shaft, I will mod the drawing - perhaps as an optional construction. As to trimming the back of the new pulley - that is why it was lengthened, I guess we didn't add enough. I could mod for that too if you provide the info.

WILL YOU STILL HAVE TO TRIM IT WITH THE WASHER IN PLACE? - wAIT, HOW CAN YOU PUT THE WASHER IN PLACE WITH THE PULLEY PENETRATING INTO THE EXISTING HUB?

 

[wilcoy02]

lookin good countryboy.
Can anyone give me the alternator mfg/number your using? I can not find the 88 firefly in my neck of the woods.
Also what 9/16 tubing are you using for the dowels?

Looking forward to starting my adventure on my lady.

 

[fysty-1]

lookin good countryboy.
Can anyone give me the alternator mfg/number your using? I can not find the 88 firefly in my neck of the woods.
Also what 9/16 tubing are you using for the dowels?

Looking forward to starting my adventure on my lady.

Here is one ploace you can look. I have this altenator( not installed yet) & it is only 4" od and you do not have to cut off an ear.
https://www.rareelectrical.com/p-1733-ne ... -8162.aspx

 

[wilcoy02]

FRSTY-1 thanks for the link.
As I understnd it this one is 140mm from front of pulley to rear of the unit. Will it not be 10 mm too long? As the 130 just touches the carb.
will the crankshaft pulley go out another .394 in or 10mm to acomodaate this one? To have a straight lieup for the belt?
Still trying to figure it all out.
Thanks again.

 

[dan filipi]

Going forward, why not insure 'the washer' isn't left off by incorporating it into the pulley? You have to hogg the material off anyway - leave some on to form the washer and it can never be left off! It is also better mechanically than a stack of rotating parts held in place by a bolt. If you can provide the OD, thickness and location up the shaft, I will mod the drawing - perhaps as an optional construction. As to trimming the back of the new pulley - that is why it was lengthened, I guess we didn't add enough. I could mod for that too if you provide the info.

WILL YOU STILL HAVE TO TRIM IT WITH THE WASHER IN PLACE? - wAIT, HOW CAN YOU PUT THE WASHER IN PLACE WITH THE PULLEY PENETRATING INTO THE EXISTING HUB?

The washer center hole needs to be drilled to accept the pulley's center

 

[MagnAndy]

So the 0.120" lead on the end of the pulley goes into the washer not the existing hub? That would trap the washer between the step and existing hub BUT it wouldn't leave much of the lead left to enter the hub and anchor the pulley. If I am interpreting the fit up correctly, it would put a lot of rotating side force on the bolt - but bolts are designed to take a primarily-axial tensile-force.

My suggestion was to maintain maximum penetration into the hub by the pulley and have the pulley shoulder directly contact the hub - the washer could be incorporated into the pulley simply by leaving material on that the current design calls for removing.

Please let me know if I am misunderstanding something - remember I have never seen one of these mods.

 

[joedrum]

this is getting a little to tecky ....when its not an ideal situlation to begain with ....it hard to get all stress out of the cerankbolt when theres no roo for it ..the only thing id see close to doing something like this ...would be a canfer in the bottom of the cutout so it could wedge tight outside of crank pulley ...but this is overkill...were operating a altinator ..some good locktite deep on the cutside edge is good enought to releave vibration and stress on crank bolt ...id say ...just great work countryboy ...thanks for contributing so huge for this forum :mrgreen:

 

[MagnAndy]

Joedrum: if you get the "tecky" right, you end up with dependable low maintenance service as in: mod it and run it for years - as opposed to mod it and re-mod it and re-mod it half way from home. That's why tecky is important. Tecky can be our friend.

As to wedging outside...this design is wedging inside and mating on the end faces. Same result - but lack of wedging with a drilled out washer was a tecky concern of mine, so we are on the same page there, bud. Thanks for your input.

 

[joedrum]

thank you andy.... :mrgreen:

 

[MagnAndy]

YW Joe, I'm a tecky guy by inclination and by training - it comes naturally to me. I know that that is unusual, most people have enhanced skill sets in areas that I'm a dunce in - they put up with my social foibals and I make allowances for their terrible, shocking, unimaginable failings in the interpretation of the physical world. :smilie_happy: :smilie_happy: :smilie_happy:

[EDIT] - Oh Crap! That reads like it is aimed AT you - sorry, not intended that way, just another social ineptitude on my part.

We are good Joe.

 

[joedrum]

yes lively debate on things is good not bad ...freedom of speech is big here ....thin skined offended people of one sort or another is just plain sensorship personaly i will have none of it in my life ...ive never been taken out by a sentence of words yet....

maybe i havnt been following good enough yet ....seems like there sould be no washer in between the two pulleys ....iguess there sould be a notice of how hard the crankbolt is thats being use ...as there is going to be added stress....

on the plus side ...the oldwing motor is the smoothest hard mount bike motor out there when running right and vibration is nill ....

having a pulley to for ones that have no access to such machines to make one is huge ...

 

[fysty-1]

I don't know what all the confusion is about. This style of pulley incorparates the whasher & spacer/bushing that is supplied with PP. And as the pulley is inserted into the Crank Pulley(CP) & keyed to the notch in the CP & on the other end(belt side) there is a raised portion that would serve as a washer. If I am wrong. then I guess that I too am confused. The whole reason I jumped in with both feet here & promoted this on other forums, is because it is one piece & keyed.

 

[dan filipi]

Maybe I can clear up any confusion.........

The pulley IS one piece in that the pulley and spacer are machined as one.
There is however a washer which sits on the crankshaft that provides a raised edge to keep the timing belt on the crank pulley.
This washer needs to be drilled to allow the new pulley center to go through it.
Easy deal.
On mine......even with this thin washer between the crank and the new pulley there is still enough metal contact with the keyway, IMO it's enough and I don't see there being an extra "stress" on the bolt.
The bolt btw has to be purchased since the old one of course is too short.
I used a case 8 hardened together with blue loktite.

I've run mine about 10k miles and have had the pulley off several times for various mods and see no stress whatsoever on any of the parts, especially not the keyway because with the loktite and torquing the bolt that pulley doesn't move around.
That is the whole idea with a proper fitting part, to eliminate "slop" that would let it move around and wear.