Valve Shims

best way to measure the closing shim?

[jerry]

Originally Posted by analogue_rogue

best way to measure the closing shim?

Tou need the adaptor and a digital micrometer

get adaptor from EMSDUC and the micrometer is about £20 in machinemart

whats the adapter?
have you got a picture?

[slob]

http://www.kaemna.de/cms_en/katalog....el&artikel=552

[utopia]

If you're familiar with the use of a micrometer it is possible to measure them without the adaptor, but it requires a good engineering "feel" or else its easy to get it wrong. The problem is that you need to measure from the broad flat face that the closing rocker bears on, to the shoulder in the bore (that holds the wire collets). BUT I believe this shoulder is NOT FLAT, but radiused to match the cross section of the wire collets. This makes it easy to get a high reading. The true reading is between the innermost corners of the face and the shoulder, where they meet with the bore of the shim. In practice this boils down to being the smallest reading you can get before the anvils of the micrometer slip off into the bore. .....Anyway, the adaptor eliminates this problem ...it fits against the radiused shoulder sort of like a spacer, and you measure across both, then subtract the length of the spacer. Brancato Engineering OX44 7RW, 01865 891203 make one (they call it a button) £23.50 (see Classic Bike apr '08). I've not tried one. Any such device has to be trusted to be accurate, until you've bought a shim of known thickness to check it against, that is. Some shims have thickness marked on them anyway. And a word of caution.... I've seen respected Ducati mechanics measure shims wrongly using Ducati workshop tools. Set the closers even slightly too tight and it all goes crunch, so with belts off and opening rocker disengaged, check that the cam rotates by hand with no tight spot. AND FINALLY, the wire collets bed in to something like the difference between one shim size and the next, so fitting new ones can restore valve clearances on their own (for a while)....or just confuse the issue. They also bed in one way, so if you put the old ones back in upside down (cos they fit either way) they act like new ones and change the clearances by maybe one shim size. And you need a lens to spot the wear marks, and then its not easy. My advice would be ..measure up, take notes, leave collets in situ, work it all out but don't change anything unless it needs at least two shim sizes, and maybe then just go one size with new collets. Or even try just new collets first....they only cost pence but shims are pricier. Check the videos...the guy from california..excellent. And do use the trick method of measuring the closing clearances via the opening shims...much easier, more accurate and doesn't chew your feeler gauges. Btw, those red kites round your way are stunning, aren't they?

Originally Posted by utopia

If you're familiar with the use of a micrometer it is possible to measure them without the adaptor, but it requires a good engineering "feel" or else its easy to get it wrong. The problem is that you need to measure from the broad flat face that the closing rocker bears on, to the shoulder in the bore (that holds the wire collets). BUT I believe this shoulder is NOT FLAT, but radiused to match the cross section of the wire collets. This makes it easy to get a high reading. The true reading is between the innermost corners of the face and the shoulder, where they meet with the bore of the shim. In practice this boils down to being the smallest reading you can get before the anvils of the micrometer slip off into the bore. .....Anyway, the adaptor eliminates this problem ...it fits against the radiused shoulder sort of like a spacer, and you measure across both, then subtract the length of the spacer. Brancato Engineering OX44 7RW, 01865 891203 make one (they call it a button) £23.50 (see Classic Bike apr '08). I've not tried one. Any such device has to be trusted to be accurate, until you've bought a shim of known thickness to check it against, that is. Some shims have thickness marked on them anyway. And a word of caution.... I've seen respected Ducati mechanics measure shims wrongly using Ducati workshop tools. Set the closers even slightly too tight and it all goes crunch, so with belts off and opening rocker disengaged, check that the cam rotates by hand with no tight spot. AND FINALLY, the wire collets bed in to something like the difference between one shim size and the next, so fitting new ones can restore valve clearances on their own (for a while)....or just confuse the issue. They also bed in one way, so if you put the old ones back in upside down (cos they fit either way) they act like new ones and change the clearances by maybe one shim size. And you need a lens to spot the wear marks, and then its not easy. My advice would be ..measure up, take notes, leave collets in situ, work it all out but don't change anything unless it needs at least two shim sizes, and maybe then just go one size with new collets. Or even try just new collets first....they only cost pence but shims are pricier. Check the videos...the guy from california..excellent. And do use the trick method of measuring the closing clearances via the opening shims...much easier, more accurate and doesn't chew your feeler gauges. Btw, those red kites round your way are stunning, aren't they?

Excellent description. Worthy of a sticky IMO.

[slob]

Stuck, here are the links to the YouTube videos and EMS

http://www.youtube.com/watch?v=dIj3nSJGPZw
http://www.youtube.com/watch?v=3WQY1MRlmH4

http://www.emsduc.com/products.html

Originally Posted by slob

Stuck, here are the links to the YouTube videos and EMS

http://www.youtube.com/watch?v=dIj3nSJGPZw
http://www.youtube.com/watch?v=3WQY1MRlmH4

http://www.emsduc.com/products.html

Anyone notice in the second vid that he torqued the top left valve cover cap head twice and forgot to torque down the top right...Ooops.

Very interesting vids, wondered how the valve gear worked. Why did he push down the closing rocker to measure the closing clearance though? What force is he trying to overcome?

The red ktes are where im from but im now up in the midlands near wolverhampton... but i cant change my location!

[utopia]

So if you're in wolverhampton, you're not far away from me in Leicester. I'd be happy to measure your shims for you if you can get them here. I've got a spare micrometer that you could borrow too, although its an imperial (inches) one, so you'd have to convert to mm.

i wont be doing the tappets till the winter season hits as i use the bike daily at the minute. but my plan is to remove engine and strip for painting then on reassembly put new shims in to stop the ticking from the valves... if you fancy a visit with tools closer to the time i have tea and coffee and biscuits... lol

[utopia]

Let me know when you're doing it. I have family in shrops, so could maybe call in en route. Where exactly are you?

Raf Cosford......

[utopia]

Oh thats easy then. I'm often in Newport, or Muxton.