clutch for 1/2 inch shaft > who has it?

[abernathy]

where can i get a clutch for a 1/2 in. shaft (1/8-in key) ???
specifically need 10-tooth #35 drive sprocket.....(9T also OK)

clutch is for ancient/historic 1950's Briggs 5 S (6 S is same).
..i have two 5 S's , still running good......
...very similar engine is shown in DIY engine in "Mounting Plate" photo, and it looks like 1/2 in. shaft also....

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I actually had a clutch specially made, but it came with #41 teeth, and supplier says he can't make it with 10-tooth #35 pitch....(ten-tooth 35 sprocket diameter is too small for his shaft adapter to 1/2 in.)

i need #35 pitch so i can use the 72-tooth #35 driven sprocket, with small diameter tires.....which i can't use the #41 72-tooth sprocket because it's so big that it drags the ground with small tires.....

sprocket and tire set up is to get maximum torque step-up (7.2 ratio) for the small engine, which it needs........

if posting, pls also reply directly to abernathymail@earthlink.net so i don't have to continuously check the forum!....(TIA) Lou

[Russ2251]

where can i get a clutch for a 1/2 in. shaftOn rare occasion they can be found on Ebay.
clutch is for ancient/historic 1950's Briggs 5 S (6 S is same)½ shaft is correct for 5S. 6S shaft is ⅝.
Also, 5S is .8 to 1 hp. 6S is 1½ hp.
2 inch bore by 1.5 inch stroke on 5S.
2 inch bore by 2 inch stroke on 6S.
I have several of each. Unfortunately, they're not worth very much as there were about 1.7 million 5S and 984,394 of the 6S produced. A lot of them still around.

[abernathy]

tks Russ, for the reply....
i'll keep checking ebay.....i'm deducting that nobody makes a 1/2 in. bore #35 clutch anymore (??)

a solution based on Russ's post might be a 6S crank in a 5s block(??)......
Obviously would have to use 6S rod and piston (1.5 stroke goes to 2.0)....but bigger problem would be end bearings for 5/8 in. shaft instead of 1/2 in. shaft....and other probs if blocks differ.
anybody stroked a 5S to 6S ??
(TIA) Lou

[Kenny_McCormic]

Could you use a 60 tooth instead.

[Russ2251]

a solution based on Russ's post might be a 6S crank in a 5s block(??)......Not interchangeable.
but bigger problem would be end bearings for 5/8 in. shaft instead of 1/2 in. shaft....Same bearings. Crank will fit block but stroke is wrong.
and other probs if blocks differ.6S block is taller. Compare cylinder fin count.

[abernathy]

tks Kenny....('use 60T') >
yes, with only a #41 pitch clutch avail for 1/2 in. shaft, looks like i'm condemned to 60T 41-pitch >
> prob is 60T #41 at 9 7/8 in. diam. leaves the chain only 1/2 in. above dirt with 11 in. tall tires> (good thing it's a big, tough chain > bad it's heavy and so is sprocket)
> can't go taller on tires because that reduces torque and increases speed.....avoiding both those due to tiny engine, and kids driving...
> #35 is better all around > lots more flexible because of smaller sprockets (can use 72T w/10 in. tires), smaller chain (less
friction), less travel to get engine placed right, lighter sprocket, etc
> but i will indeed have to get #41 60T....

aside to Rick....taller block interesting solution to more stroke....probably involved other things like like making the valve stems longer, or moving cam upward in block....
Chevy simply moved the piston pin higher in the piston for more stroke in small-blocks....was expecting that

PS: valves > do you know offhand, what 5S clearance should be ??

[Kenny_McCormic]

You could use a jackshaft.

[Russ2251]

valves > do you know offhand, what 5S clearance should be ??Don't know off hand but is stamped on ID/nameplate (around cylinder fins).