crank topic, more question?

While playing around with my crank , I had just noticed the timing bearing inner race was "sliding fit on the crank....try to find out in the forum what are the recommandations but......., don't found!
through that , my static balance is at 70% (ish...), start with the kitchen scale , but this morning , go to my friend and accuratly weighed the lead's counterweight , then hung them through the oil hole by a string, two old 6306 ball bearings kept in place by nails on two wooden lugs , and presto the balance jig is on..........a bit primitive , but cannot do better in my shed.
in fact I just want to check if the BF was OK , cause my friend who milled the counterweight can't remenber what he had done (he's getting old too...!) next , I will shim the outer race to 0.004" (according Jim's note's) and grace to Dog T who sent me to France the shims (difficult to find them here , just inner shims, though with my easy to slide inner race , if I knew!!!)
It's a real great pass time , everybody play in the shed at his own level, and I say I really appreciate that positive attitude, when sharing infos, whatever the level of knowledge........

I always thought the inner races were a press fit on both sides, not sliding fit.

Dave
69S

Hi Dave, yes I agree with you it should be a tight fit.....since I had posted , I had found a Ken Kanaga topic about copper plating the inner race of the bearing , but it's out of my possibilities.....but i had noticed he had tried to loctite it twice witout good results.........so ?

If the loose race is on the timing side I would use a little locktite bearing mount and you should be fine. When you torque the oil pump drive gear it will hold the race tight so it shouldn't spin and cause any problems.
However a loose drive side bearing must be repaired either with plating or installation of a bushing. Jim

I want to know more about the balance jig! I am having a little trouble picturing the process.

Hi Jim , thanks .............
will take some pics tomorrow for you RV Rich, but you will not be impressed by my High Tech jig.....typically mechant navy bodge.....! like when nobody can see you in the middle of the ocean!

If rubber mounted pick what ever BF you like, its the dynamic side to side balance the matters to isolastics. If solid mount 70's BF is current extremists experiment being done by Kenny Cummings with Jim Schmidt special light piston-rod kit. Ken has twice fractured Sealy frame from vibration with 80s BF that are supposed to be easier on frames. So toss your BF coin and let us know your sense of it.

Ken Canaga plated Ms Peel inner races because of worn under size crank ends but 'goofed' first time finding bearing clearance so tight installed in cases it bound crank to spin until he relieved a few 10,000ths. Gets looser when at operating temps thank goodness.

Mr Hudson of Norton factory fame in his video shows him hand sanding TS crank end to accept a ball bearing easy slide on and off by hand at room temps.
It stated loose enough could been tapped easy on off but he kept repeating sanding and testing till it would fall on/off by gravity alone. Ponder that for experts wisdom concern on TS fit.

So Comoz advice it don't matter much seems spot on. Absolutely do not expect any locktite to hold any thing tight in a hot vibratiing Norton, gear box to engine. Never heard it working in over a decade of reading those who tried.
Studs sure but not bearings in bores. Everyone found race spun as before.

I may seem clueless but these 'hi temp' loctite are not that new that Norton builders ain't already tired them. So test it yourself and see. I hold that if lose enough you'd think to use Locktie in gear box or engine best think of another way. Might review instructions to remove a stud or race with 'hi temp' on em.

Locktite will do nothing as far as keeping a loose bearing tight on a crank, but since the bearing is retained by the oil pump gear locktite will provide a little cushion to prevent the two metals from fretting. I would never suggest that you should work the crank down to provide a slip fit for the bearing unless you are racing and need to take it apart often and have a ball bearing on that side. Jim

Have no fear of 243. It`s medium strength and easily broken with expected forces. Standard issue for KTM 640 singles (SHAKERS).

Maybe as Jim's says Loctite is somehow good as a galling cushion-lube when race spins to save further wear. I dare ya to Loctite a bush or bearing in tranny or engine and knife edge mark postion or just look at the bore some short time down the road. Others may have faith in this application but I've lost mine. i await a single report of success, sorry. I use blue and red Loctite only on threaded stuff.

I am not an expert but I do know that a drive side bearing journal in critical. You need to get that thing measured. Weigh your options. I don't believe plating is viable. I am also not sure of the stresses welding and regrinding will put on the crank, but it is an option worth researching.

I might think that an undersized bearing my be the best solution. Please realize that superblends are not the only choice and there are many quality bearings. Again, your need to mic up the journal and find out exactly where you stand.

hobot said:

I may seem clueless but these 'hi temp' loctite are not that new that Norton builders ain't already tired them. So test it yourself and see. I hold that if lose enough you'd think to use Locktie in gear box or engine best think of another way. Might review instructions to remove a stud or race with 'hi temp' on em.

Click to expand...

Actually you do, but the new series of loctite only come out last year from memory

rvich said:

I want to know more about the balance jig! I am having a little trouble picturing the process.

Click to expand...

Here is one way check the balance factor of a crank. I made this jig years ago with a pair of forktubes ,a set of Maico triple clamps, a set of Ossa triple clamps, a couple peices of aluminum bar and four small bearings.
I use soft copper wire to hang the weight through the oil holes and add washers till the wire hangs straight through the center of the holes. Then I measure all the hanging weigh and use that to figure the balance factor. Jim

Thanks for the pics...once again a photo is worth a thousand words.

marinatlas said:

It's a real great pass time , everybody play in the shed at his own level, and I say I really appreciate that positive attitude, when sharing infos, whatever the level of knowledge........

Click to expand...

+1

comnoz said:

Here is one way check the balance factor of a crank. I made this jig years ago with a pair of forktubes ,a set of Maico triple clamps, a set of Ossa triple clamps, a couple peices of aluminum bar and four small bearings.

Click to expand...

My goodness Jim, necessity is the Mother of Invention.

This evening I have been working on balancing the crank for my new 924 engine. Was almost considering raising the balance factor.

I have a customers bike here that was known to be an exceptionally smooth running stock MK3 850 and I am doing a minor refresh on the motor. So I took advantage and put his crank on the jig and weighed all his parts. 3 times

The balance factor came out to 49% wet and 59% dry.

Guess I am going to stick to 50% wet like I had planned. Jim

comnoz said:

Here is one way check the balance factor of a crank. I made this jig years ago with a pair of forktubes ,a set of Maico triple clamps, a set of Ossa triple clamps, a couple peices of aluminum bar and four small bearings.
I use soft copper wire to hang the weight through the oil holes and add washers till the wire hangs straight through the center of the holes. Then I measure all the hanging weigh and use that to figure the balance factor. Jim

Click to expand...

Great minds think alike, Jim. This is the balancing stand I made a while back from some scrap steel plate and surplus ball bearings. It's shown checking out the drive side runout, but I also use it for static balancing. If I were doing it over, I'd make it taller. I have to keep the wires through the rod journals pretty short so the weights clear the base.



Ken

Yeah, the biggest difference is that I was into Kawasaki triples when I built mine. It's a little longer than yours. Jim