Great idea. This is the sort of thing I was thinking about when I said we need a database but I never thought about using Google.
@Ducbird is there any way to insert a post of the top of the thread with the link to the spread sheet in it for easy access?
Good idea. The OP can do that @Pauldonjuan via the edit post function. Oh, I've just realised you meant an entire post. Still PDJ can do it in his original post at the opening line.
I did a valve service on an ST2 last week and now have an 8mm shim at 7.05 available, but can't add it to the database myself.
I’ll edit the spreadsheet when on my laptop in the morning, need to download an app to do it on the phone.
@Pauldonjuan @Derek @West Cork Paul @Ducbird Well done to all of you .... great work ! Maybe it's going to be a "labour of love" to keep it maintained but it will be a great resource for all members who do their own valve work . I'm very much into sharing of knowledge , resources etc. and a forum would seem to be the ideal place but the very nature of forums often means that important threads ( for reference ) get pushed down the list , by new topics coming in . I'm hoping that this project continues to grow , and that it can be easily available to all ..... Thanks again to all
@Ducbird made it a sticky at the top of the Technical Help section (thanks Viv) so it shouldn't disappear into the far most recesses of the Forum
In my ignorance I just need to know the difference between the 7mm and 8mm ones. I presume 8mm ones are for the desmo due engines and 7mm for the desmoquattro
That's always been my understanding ..... doubling the number of valves means less load per valve so valve stems can be thinner . But I'm just " speculating about a hypothesis " here , so the facts could make me out to be an idiot ... There's folk on here who probably know every model ..... chapter and verse I'm sure someone will be along soon ....
8mm fit all 2 valve Ducati engines from the 750SS of 1972 right until the Dual Spark engine was introduced around 2003(?) when the moved to 7mm. The 8mm openers will also all the singles but these have a different arrangement for the closing clearance. 7mm fit all the 4V engines from the 851 on but I believe there was a small change to the closer when the 1098 was introduced but the shims can be retrofitted to older engines. As far as I'm aware, the Panigale uses different closers with half-ring collets for the inlets and tapered collets for the exhaust. FYI. The same size 8mm openers were also used on some Alfa cars and may be a cheaper option.
Yes. 4 valves means smaller valves for the same port area, smaller valves means less weight so less inertia. So for a conventional valve spring engine higher revs before valve float sets in and for all engines less load on the valve gear. Of course the other advantage of 4 valves is that you can get a bigger port area into the head and with a desmo engine you can open the valves quicker and for longer.
Yes indeed .... agreed on all points . Valve float is the enemy ..... " make it go away " Inertia / momentum ..... minimize it , but not at the cost of reliability
The single cylinder late 60's early 70's Desmo's can be converted to use the twin cylinder 8mm closing shims. They can also be converted to use the Desmo twin's helper springs, thus doing away with the Hairpin springs. It's a performance mod' that also makes them easier to adjust/work on. I've carried out these mod's on my little '74 250 Desmo. Steve R
Hi, I don't know how to update the spreadsheet database. The 7.00 8mm closer I have on is no longer available if someone can update please
