Shims

Post your general FAQs, comments & questions regarding all Ducati engine & transmission restoration here. [Specific engine FAQs should go in the 'BevelHeaven Garage' section.]
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Crashfangio
Mariana
Posts: 35
Joined: Fri Aug 15, 2008 6:48 pm
Location: Melbourne Australia

Shims

Post by Crashfangio » Tue Nov 17, 2009 10:16 pm

Does anyone of our members from Australia (Melbourne) know of a good local source of engine shims suitable for a Bevel??

In particular I require a selection of mains shims to set the correct crankshaft end float. It's also possible that others will be needed when I start measuring up the top end, although mains will do for now.

2nd question, is it desirable to keep the mains as one single shim for each side or is acceptable to run two together, only if required.

Finally, I take it that there must be an equal size (and number) of shims on each side in order to keep the crank right in the center of the engine, or does it not matter??

Advice will be greatly appriciated.

David
73 750GT

BEVEL DAVE
Diana
Posts: 62
Joined: Sat Jun 13, 2009 7:22 pm
Location: SYDNEY, AUSTRALIA

Post by BEVEL DAVE » Wed Nov 18, 2009 1:22 am

You can use 2 if needed but no. is not critical, yes centred is better but not critical either.
I have shims but you will need to let me know what you need. I will see what I have in stock.

Dave.

rwhc80
750 GT
Posts: 174
Joined: Sat May 16, 2009 7:19 am
Location: Melbourne Australia

Post by rwhc80 » Thu Nov 19, 2009 2:10 pm

David,

you should consider joining the DOCV. Ducati Owners Club Of Vic With a 73 GT it will give you access to use the extensive set of club tools inc the shim kit, along with stacks of reference material. You only attend meetings and club days if it suits you, but the access to the equipment is worth the membership alone.

Cheers
Rick
I have desmo disease, I just hope they never find a cure !!!

Crashfangio
Mariana
Posts: 35
Joined: Fri Aug 15, 2008 6:48 pm
Location: Melbourne Australia

Post by Crashfangio » Fri Nov 27, 2009 2:12 pm

Thanks Dave. I've managed to source the sizes I need through Chris Bullen at Precision Shims here in Melbourne. I have reassembled the bottom end and all seems well thus far.

I have got just on 0.01mm play, which I am happy with considering the mains bearings are original and probley a bit worn. I would prefer just a tiny LITTLE slack rather than the bearings being loaded up. Anyway, it is better than what it was prior to disassembly.

Rick, I checked out the DOCV website and I think they will have my membership in the new year. Thanks for the tip.

Cheers, David.
73 750GT

rwhc80
750 GT
Posts: 174
Joined: Sat May 16, 2009 7:19 am
Location: Melbourne Australia

Post by rwhc80 » Fri Nov 27, 2009 7:02 pm

David,

Unless I miss understand what you're referring to , be careful !!!
The crank in beveldrive engines should have no endfloat. infact they should have preload due to the angular contact bearings. these bearings are designed to run under load.

Regards
Rick
I have desmo disease, I just hope they never find a cure !!!

wdietz186
Cagiva Alazzura
Posts: 703
Joined: Sun Sep 10, 2006 5:40 pm

Post by wdietz186 » Fri Nov 27, 2009 7:31 pm

The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up.Remember the cases expand when hot and the bearings are designed to run with some preload.Shoot for .25-.30mm on the trans shafts and shift drum.It is time consuming to get it right but oh so satisfying when you do.

stian buksa
Cucciolo - the Lil Pup
Posts: 20
Joined: Mon Oct 12, 2009 11:50 am

without micrometer

Post by stian buksa » Wed Jun 09, 2010 3:48 pm

Any tips to how to measure the crankshaft preload without fancy instruments ?

With 0,50 mm shims i can feel that the crank is a little "loose"
With 0,60 mm its tight, with a minimum of drag
With 0,75 mm its tighter, with more drag

Which one should I go for ?


71 750 roundcase GT

bobnorton
860 GT / GTS
Posts: 281
Joined: Wed Jan 16, 2008 2:18 am
Location: bromley kent

Post by bobnorton » Thu Jun 10, 2010 12:39 am

Beware that the shim does not sit against a tiny crank radius or it will get loose in no time .

Den
Mach 3
Posts: 89
Joined: Fri Apr 09, 2004 6:02 pm
Location: Florida, USA

Re: without micrometer

Post by Den » Fri Aug 27, 2010 5:56 pm

stian buksa wrote:Any tips to how to measure the crankshaft preload without fancy instruments ?

With 0,50 mm shims i can feel that the crank is a little "loose"
With 0,60 mm its tight, with a minimum of drag
With 0,75 mm its tighter, with more drag

Which one should I go for ?
71 750 roundcase GT
To do it right you will want to measure the crank end float with a dial indicator. Measure the end float and then add an extra 0.004".

.

stian buksa
Cucciolo - the Lil Pup
Posts: 20
Joined: Mon Oct 12, 2009 11:50 am

measured pre load: How tight ?

Post by stian buksa » Thu Aug 18, 2011 9:28 pm

I've found two methods of finding the correct amount of crankshaft pre-load described on this forum:

"The generally accepted preload on the cranks is .05-.10mm[.002"-.004"] You should feel some drag but the crank should fall on its own when the heavy part of the flywheel is up" - wdietz186

"To do it right you will want to measure the crank end float with a dial indicator. Measure the end float and then add an extra 0.004"." - Den

Do the amount of pre-load using the two different methods end up as the same ?

Or to say it another way: How tight will the crank be using the "dial indicator method" ?

I have adjusted the end float twice, using the first method, but it ends up loose after a few thousand kms. The first time I used the smaller diameter shims which didn't work well because the base was a little concave, but now it is loose again

I'm afraid to put too much pre-load as this will stress the engine too much I guess ?

Stian

(Also submitted as a new topic in the roundcase section)

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