Hello everyone. I've finally opened the engine today and removed the camshafts. Those are the measurements I've got. In same cases what's written on the side of the shim is different from what I've measured (I did clean the shim and measured multiple times). Now that I'm about to run the calculations for replacing the shims to get the clearance within spec, which ones should I follow? Mine or the ones written on the side of the shim? The openers should be between 0.13 and 0.18 and the closer 0.05 and 0.10. Thanks for any help.
The shims may have worn down, so use the values you've measured not what it says on the side. I'm going to be taking on the job shortly and I found this guys video very useful:
I am trying to do this at the moment too (but just being very slow) and I measure the shim with a micrometer and then add on what I measure the clearance to be out by with the feeler gauges. Opening shims, especially, will wear very, very small amounts, so only go by your own measurements and not what is stamped on the shims. And a long time ago, in my Darmah days, being a cheapskate student, I do have a memory of removing some metal from shims with emery paper, said Mr Bodger
In all but one case your measurements are slightly higher than what’s stamped on the shim. How are you measuring them? Vernier or micrometer? And I presume you’re using a shim measurement tool which fits into the opening & closing shims? I wouldn’t worry about where there’s a 0.01mm difference between what you measured and what’s stamped on the shim but the bottom right closer is a big difference at 3.35-3.41. Personally, I’d double check the ones that are way off. IME what’s stamped on the shim is usually correct and that’s what I’d work off. However, it doesn’t really matter whether you use your measurements or what’s stamped, you’ll need to remeasure the gap once youve changed the shims and on some valves eg that bottom right one you may need to order a couple of shims so you have some options to get the best fit. It looks like you’ll be ordering about 19 shims unless you can swap some around and reuse them, I’ve not looked at it in that much detail.
I'd agree that the difference may well be coming from the measurement tool you are using. I had the same situation, admittedly on a old bevel, where I'd measured the closer, calculated what I needed and ordered it. When it arrived it was totally the wrong size and no way could it be used. The reason was because the shim measuring tool I was using wasn't as accurate as the shim measuring tool the supplier was using. Have a look at the photo with particular attention to the size of the shoulder that sits on the split ring recess. Needless to say the one on the right is the accurate tool.
Typically a micrometer will fit inside the opening shim so measuring the thickness of that is usually not an issue. It’s the closing shim where, if the measuring tool isn’t a good enough fit, issues can arise as it has to sit flush in the closing shim. @Mike 999 as your larger variances (larger than 0.01mm) are all on the closing shims it does raise the question about what tool you’re using and how you’re measuring the closer.
And as a little bit more info to WCP's explanation, remember the split ring recess is cupped so the higher up the tool sits in the cup the larger the shim measurement will be.
Thanks everyone for your replies. I also thought the tool is not super accurate. I'm using a veneer and a micrometer. How a shim can become bigger than what's written on its side? The thing is I measured the tool myself with a micrometer. It's 9.03. and that's what I'm subtracting. I've measured from the top to the point when it start curving inside. Otherwise the measures would be even more off. For the opening some I can get inside with my micrometer so that's not an issue and they look pretty accurate. The tool I'm using is the one in the picture above but on the left. On the closer shims I'll be going by what's written on the side of the shim.
I have two measuring tools, for 7mm and 8mm valves. They respectively came with 10.003mm and 9.996mm certificates of measurement. Are you sure about your 9mm tool? Additionally, in my experience, you should never go by what’s written on a shim. Always do your own measurements. Always. If you go by the writings, you’ll never get the clearances you’re aiming for.
But how can the shim be bigger than what's written on the side of it? should if anything be smaller? this is what I've used https://www.ebay.co.uk/itm/151226703524
Ouch…no need to shout Maybe you just need to recognise and accept, that if you are using that tool to measure your closers, then you are not in sync with Ducati and the measurements that they take and etch onto their shims??? At the end of the day, they will be taking all of their measurements using the official tool. The only way you can make accurate comparisons is to use the same official tool. Otherwise you are trying to compare apples with oranges !
thanks man, it was only a lazy copy and paste from the website, hence the bold font. no one is shouting here
I’ve never actually checked shim measurements on a Ducati as I am probably a bit scared of doing it. Well. I’m definitely scared. Silly question but how does the tool work? Any pictures of it in action?
Now I’d gladly send you pics of my tool in action, mate, but I’d probably get in trouble for that… More seriously, I’ll post a few pics and comments on shim measurements later this morning as, you correctly guessed, it may not be that intuitive (for the closers).
Thank you. It’s probably within my capabilities to do but never having witnessed the job being done I’d be somewhat nervous of f-ing it up. Always good to learn new stuff. BTW. Keep your tool well oiled.
Jack if you watch the video link moorland monster posted it shows you how to use tool and calculate size
If I measure a shim using both of the tools in the photo I posted then the tool on the left gives the larger incorrect measurement. It is of no use but ornament. The measurement you take is of the tool & shim combined - and you then subtract the length of the tool from it's shoulder to the top from that total size to give the size of just the shim. So the length of the tool doesn't matter. But what does matter is where the tool sits in the shim. As previously mention the tool on the right has a tiny tiny shoulder on it so will sit as low as possible in the shim's curved split ring recess. The tool on the left has a much larger shoulder on it so will sit much higher up in the shim's curved split ring recess and it will therefore result in a larger shim measurement:
