[clenart50]

I'm doing my first valve job on my 04 999 and i'm pretty sure i've made a mistake somewhere. All of the opener clearances are .004mm or less. some are <0.002. closers range from .003 to .007.

my understanding is that opener clearance should increase with time, not disappear. below is a pic showing the cam position. i'm pretty sure this is TDC on the compression stroke. valves are clearly closed when i rotate the engine a bit either direction.

any ideas?
thanks
chris

 

[frankfast]

As the valve seats itself, the opening clearance will become smaller not greater.

 

[clenart50]

thanks.
it's amateur hour in my garage right now.
i'm going to remeasure everything and then take the leap and pull the cams, etc.
chris

 

[ericjansen]

thanks.
it's amateur hour in my garage right now.
i'm going to remeasure everything and then take the leap and pull the cams, etc.
chris

You talking about measuring BEFORE you pull the cams right?
The so to say 'old' situation.

Be absolute sure you have these clearances right, as they are the base on which you will do everything else.
Getting it wrong will waste everything else you are going to do from now, only to find out if you do the final check after re-installing everything.

 

[clenart50]

Correct, my cams and belts are still on. I'm going very cautiously because I have the luxury of time and I want the job to be done perfectly (or at least pretty ok).

 

[BrianG]

Make sure you get the new Testastretta valve clearances. Ducati changed them. Much tighter than in the book.

I believe LT has them posted.....

Also, note that the base circles may not be perfectly round. Measure your clearances all around the base circle, not just at 180 degrees from the lobe center, and set to the tight spot.

 

[ericjansen]

Make sure you get the new Testastretta valve clearances. Ducati changed them. Much tighter than in the book.

Wahhh, you kidding us?
I got 0.18~0.23 for opening (0.20 target) and 0.13~0.18 for closing (0.15 target) and just ordered the new shims based on that.....

 

[st2lemans]

0.1mm openers/closers as I recall.

Tom

 

[ericjansen]

0.1mm openers/closers as I recall.

Tom

Is this mandatory from Ducati, or will it improve performance or life?
Is there a downside to it?

 

[clenart50]

I got 0.18~0.23 for opening (0.20 target) and 0.13~0.18 for closing (0.15 target) ....

These are the precise numbers i'm using. LT's book uses them, as does the 999 service manual.

 

[BrianG]

These are the precise numbers i'm using. LT's book uses them, as does the 999 service manual.

If you read LT's blog entry for Aug 19, 2009 you will see that the closer clearance has been revised to 0.002" for the 1098, and LT recommends this revision for all Testa engines. Apparently opener clearances remain unchanged. In the blog LT suggests that he will be making this revision in any upcoming version of his manual.

Many of us find ourselves in the same boat, having just completed the adjustment process to the OEM clearances.

Oh well, this will keep me out of the bars for a few nights this winter....

 

[frankfast]

The old beveldrives were .000" on the closing rockers. The only way to check them was to take the heads off and spin the cams to make sure that there was no resistance but yet not able to put a .001" feeler guage between the cam lobe and rocker. On the racebikes the helper springs were removed also since compression seated the valve. Apparently those springs are there for startup purposess only.

 

[Abandon42S]

Apparently those springs are there for startup purposess only.

Why are those springs so stiff, if they aren't really all that necessary? I suspected they were there to help keep the rockers in contact with the valve shim so that the valve doesn't get flung between the rockers end travel, but still why so stiff? Correct thinking? :think:

 

[BrianG]

They are necessary for low speed operation. It idles like crap, if at all, without them.....
They have to be strong enough to not come off at 10,000+ rpm.

 

[frankfast]

They are necessary for low speed operation. It idles like crap, if at all, without them.....
They have to be strong enough to not come off at 10,000+ rpm.

They probably float at that RPM and become totally useless. They're light enough so that the cams are not working against them which is the function of a desmo. You're right, low speed operation only. I'm not sure if you can take them out of a superbike racebike the way you could on a beveldrive. Reshimming might be in order?