Crank balancing question

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RatedSpeed

RatedSpeed

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Was it common to drill the crank counterweights and not the flywheel when balancing ?
The manual states holding the flywheel with a bar to remove the pinion nut, I doubt they want a bar stuck in the counterweight.

Mike
Crank balancing question
 
interesting that it was so balanced.... maybeto prevent a rocking couple .the impoertant one isto ensure the conrods weigh the same... for some reason the factory stopped doing this
 
Just looked at a 72 crank, only has holes drilled in the flywheel, none in the counterweights except for a capped off oilway drilling.

If they were drilled as part of dynamic balancing then I would expect them to be only on one side ie the heavy side.
 
I thought it may have been from dynamic balancing, but was confused by the lack of flywheel balance holes that the manual says to use to hold the crank steady, as if all crankshafts have them.
 
2 holes in my 85 flywheel.
Never seen holes outboard like that in the 4 engines owned previously.
 
Does anyone have a flywheel on the shelf that can provide a width measurement ?
I'd like to know if this is a 850 flywheel.
This is a 2111** crankcase with 850 top end.
I'd like to get an idea of what's going on before I tear it down.
Here's a photo where you can see what little sealing surface there is between the case and jug spigot on the drive siide.

Mike
Crank balancing question
 
Would be interesting to see who balanced this crank. We used to spin balance pump shafts and could tell differences from side to side, but these operated at a much higher rpm then a Norton. Someone had a better idea. Or a very expensive balance machine
 
Yes, I wish I knew more about it. I purchased the bike in 1994 and it's been sitting in the back of the shop and the guy I bought it from had it in his house for 10 yrs. prior to that because he said the kick start lever kept dropping, but supposedly it had engine work done by a Ed somebody in Norristown, Pa. Who used to race? ( drag ) a norton labelled
" snortin' norton " , so maybe he had a different means of balancing, who knows.
 
YES !! That's the guy.
I believe he was a Norris cam dealer, and this motor has the Norris 336 cam.
Doesn't mean he did it, but I think the pieces are starting to come together.
Thanks,
 
Great detective work.
Kick lever dropping usually means the lay shaft bearing is on it's way out , which is dangerous stuff.
Plan accordingly.
 
Thanks for the heads up !!
I've been gathering info on this great forum for awhile now before I dig into it. That's why it sat so long, there just wasn't much knowledge to be found in my area. I talk to three people and get three different answers, so I would just put it back to sleep for awhile.
This is actually the only norton I have ever physically seen in my neck of the woods in my 62 years. Plenty of triumphs and beezers.

Mike
 
RatedSpeed said:
Does anyone have a flywheel on the shelf that can provide a width measurement ?
I'd like to know if this is a 850 flywheel.
This is a 2111** crankcase with 850 top end.
I'd like to get an idea of what's going on before I tear it down.
Here's a photo where you can see what little sealing surface there is between the case and jug spigot on the drive siide.

Mike
View attachment 83366
Click to expand...
2 and 3/16 inches max. width for the 850 flywheel sitting on the floor in front of me with the new rods bolted in. Yay ! We prefer to use 5.50 mm here in the north.
 
RatedSpeed said:
YES !! That's the guy.
I believe he was a Norris cam dealer, and this motor has the Norris 336 cam.
Doesn't mean he did it, but I think the pieces are starting to come together.
Thanks,
Click to expand...
I believe Ed balanced that crank to your piston, piston rings, the small end of the connecting rod, etc, or whoever, when the engine was built. I use Forest & Forest here in Ontario and they do the same thing with holes in the cheeks. Herb Becker uses these guys as well and he recommended them to me.
Cheers,
Tom
 
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