Valve shim spec nomenclature....Error in LT Snyder 2nd edition? Opinions please?

[kpdiamond]

Hi Valve shimming guru's!

I am doing the valve service on my 02 M620 (2V)
The bike has only ~~8700 miles and the previous owner claimed to have had the 6000 mile service done.
I have some ?'s

1--I read from EMS Ducati (CA Cycleworks?) the following quote:  " The ducati shims are made to Ducati specifications and have the size in millimeters etched on the side of each shim. The Ducati shims are made from a bearing steel and through hardened to Rc 58. The shims made in the USA do not have the sizes etched on them."

If the above statement is true, and I do not see any etching of shim size on the shims....this would mean that someone in fact was in the engine and changed the shims?

2--In LT Snyder's 2nd ed. Desmodue guide in the Valvetrain section.  He list the Ducati spec, and then his preferred spec.  My desire is to set the valve shims to LT's spec. 
          LT states he would set both IN & EX openers to .1mm
          He then states that he would set the closers to <.05mm both IN & EX  (the < symbol representing "greater than" yes?)
Does he in fact mean "greater than" .05 mm?  Or is this a misprint?
If he does mean "greater than .05mm"  for the closer shims--what would be the upper range of clearance?

I have read that it is worse to set the shim clearance too tightly,  therefore the "greater than" nomenclature makes more sense...but seems weird that there is not an optimum--or maximum clearance spec.

Currently my openers are .1 mm
and closers are .08 mm

Based on this (and lack of etching marks on the shims) I am thinking someone had in fact been in the engine at ~6k and done the valve clearance service.

I thank you and welcome your opinions!!
-Kevin

[drval85]

< means less than.

[kpdiamond]

< means less than.

Math is my nemisis, but  I would think the following:   <.05   would be read aloud as

".05 is greater than"

(jaws of the gator eats the larger #)
~if I am remembering grade school correctly?

Really not trying to flame you up, or say I am correct.  But surely confused.

[drval85]

Yeah, but in that case, ".05 is greater than" whatever you're comparing it to, which would be the shim measurement. 

0.5 > Shim opening
Shim opening < .05

At least I think. 

[SpikeC]

Think of the shape of the symbols, the big opening I'd bigger than the other end, which is a point. So < means that the left side do the symbol is smaller than the right side.
Or, 4 < 5.  So <.05 means less than .05. The idea is that the closer should be close to 0 clearance without having drag when rotated.
The openers tend to wear into less clearance and the closers tend to wear into greater clearance.

[kpdiamond]

Thanks all, and pardon my idiocy....

After all your replies, and further consults. I agree.  I believe (now) that the spec. read aloud would mean.


"the specification for valve shim clearance is less than .05"

clearance <.05

[Dirty Duc]

As I understand LT's clearances, they are for a bike that is properly flogged on a regular basis. The Ducati specs assume a more leisurely pace. What's the difference?

Carbon build up. A properly tuned performance engine that is properly flogged does not build up carbon on things like valve seats. A "babying" approach tends to build up carbon on the valve seats and "take up" the clearance.

[kpdiamond]

Very helpful explanation.  Thank you!

As it is I am doing a top end job on the bike and de-carboning everything.  So with pristine clean heads, and a proper flogging...LT's spec should be ideal?

[ducpainter]

2V Ducati's always run better with the tighter specs.

Run 87 octane fuel, assuming you're in the US on a standard compression motor and carbon build up will not be a problem. If, you experience pinging, which I doubt, run the lowest grade fuel possible to eliminate the pinging. More octane is not necessarily better.