Author Topic: A10 Engine Shimming  (Read 1684 times)

Offline mitch

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A10 Engine Shimming
« on: 14.05. 2011 14:48 »
Hi Guys, i cannot find much on A10 engine shimming. *sad2*
I have noted that the fly wheel should be shimmed for less than 3 thou clearance in the crank case (locte shim on DE side).
Also note a similar clearance for the cam shaft, before joining the two crank halves.
So what about the timing gears. These may well float around between their bushings and this may well cause some engine noise or clatter.
I followed the 3 thuu rule and shimmed the timing gears so that they meshed evenly and do not float about.
But then this was only my best guess. ????
What do the experts out there recommend please? *idea*

Offline Goldy

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Re: A10 Engine Shimming
« Reply #1 on: 14.05. 2011 17:22 »
The only timing gear that can float is the idler gear. If you put shims on the idler gear spindle they will bind on the gear and bush face and will eventually wear away. Shims can only be fitted to rotaing surfaces where they are trapped and cannot move independantly.
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Online muskrat

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Re: A10 Engine Shimming
« Reply #2 on: 14.05. 2011 21:15 »
G'day Mitch,
                 the cam end float will be 0 once the inner timing cover and cork seal is in place. 3thou for the idler sounds great as long as it's done to keep the dynamo sprockets in line. A point to watch is the gasket thickness will alter your end float so if you use a 0.8mm gasket now and a 0.4mm later you will cramp the idler.
Cheers
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Online bsa-bill

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Re: A10 Engine Shimming
« Reply #3 on: 14.05. 2011 21:38 »
The idler pinion is not that tight on it's keyed shaft so although pulling the dynamo drive sprocket up with the cork washer behind it will sometimes /often pull the pinion up against the flange on the inner case bush the pinion is able to move on the shaft so shimming is possibly not going to remain as you left it.
Doesn't really matter as the bushes are flanged, the flange being a bearing surface it's not a problem if the pinion rubs it, plenty oil floating about
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

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Re: A10 Engine Shimming
« Reply #4 on: 14.05. 2011 21:46 »
I didn't think about the cork seal Bill as neither of mine has one. I have yet to find one that lasts more than a few days.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, .
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Offline mitch

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Re: A10 Engine Shimming
« Reply #5 on: 15.05. 2011 17:30 »
Thanks Guys, for the fedback on shimming.
I have run the engine, shimmer per my best guess above and it does sound quieter than before.
Will open up ofter the first 1000  miles or so and see how it is holding up.
Cheers, Mitch

Online bsa-bill

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Re: A10 Engine Shimming
« Reply #6 on: 15.05. 2011 18:58 »
I have yet to find one that lasts more than a few days

Know what you mean muskrat the last one I took of had disintegrated, but usually they are there albeit squished a bit and gone hard, probably a question of today's quality, someone ( on here I think ) machined the case and fitted a seal

let us know how it behaves Mitch
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online Brian

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Re: A10 Engine Shimming
« Reply #7 on: 15.05. 2011 23:32 »
I put a seal in one I'm working on at the moment. Its a fairly easy job if you have a lathe.

On my other A's I havent worried about a cork seal or anything else, I find the small amount of oil that gets into the gen chain drive area is nothing to worry about. If you have a belt drive it might be problem though.

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Re: A10 Engine Shimming
« Reply #8 on: 16.05. 2011 09:53 »
Nice job Brian

The toothed belts will run even if the chamber is full of oil DAMHIK but not much oil gets in there if you fit the idler bushes in the correct order *red*
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco