/2 Crank nose bearing advice needed from experienced engine assemblers.

[malmac]

What physical design separates the bearing from touching the gear? Please see picture. GearAndBearing_LI.jpg

I assembled my engine without a spacer. The bearing outer rubber on front of gear. I turned up a spacer 1.5mm thick and installed it between gear and bearing.

I had to pull engine back down because the timing gears were just too tight when hot.
Now I have no interference between gear and bearing. I had no trouble with front gear cover seating.

I would install spacer..... that is my experience.

Regards

Mal

[huntmiller]

Malmac,
Thank you! James helped me identify the difference. (see picture) Unfortunately I don't have a machine shop but I can be pretty resourceful.

[malmac]

Malmac,
Thank you! James helped me identify the difference. (see picture) Unfortunately I don't have a machine shop but I can be pretty resourceful.
compare crank nose notes.png

James is a Wonder, so to speak.

Funny but I also have a reproduction crank which I assume your is as well.
I guess with a longer shank for the front timing gear, the nose bearing would sit proud of the gear, but with the reproduction crank I have, I needed a spacer to get clearance.

I will measure my old crank and check out the difference. Never hurts to learn.
Thanks James for the heads up.


Mal

[huntmiller]

I envision needing a sleeve with a length of about .3cm and the bearing would rest against that. The inside diameter of the sleeve would match the inside diameter of the nose bearing. The outside diameter of the sleeve would be slightly smaller than the inside diameter of the timing gear. Make sense?

[huntmiller]

Something like this...

[malmac]

Something like this...
Sleave2.JPG

I dont think it needs to be 3mm thick. Mine is 2mm thick.

Cheers

mal

[huntmiller]

Mal,
I like what you did. Slightly different approach based on what I found easily available: This bearing has the same OD as the timing gear and ID of the bearing. I might try both.
Hunt

[jwonder]

Hunt, one word of caution on your idea. The crank has quite a large bevel at the transition, or at least it looks that way from the picture. If you make a spacer that is going to sit on that bevel, it too needs to have a bevel to sit flush with the front of the crank so the bearing is on solid metal. That is not going to be that easy. Mals idea is easy and it works.

[chrishea]

I agree with James’s assessment, instead making a “sleeve” that’s the same outer diameter of that portion of the crank, making a “washer spacer” like Mal has made up should be easier. Pressing the sleeve on will get tricky trying to match the outer diameter, as the sleeve will expand when you press it on.

[huntmiller]

I agree the washer/shim would be easier to implement than the sleeve. I've been looking through my collection of misc nuts bolts and washers to find a washer with a 20mm ID. Thanks everyone for taking the time and sharing their thoughts!