Hi gents,
Could one of you give me the valves lift for my 1937 Model 9 ? Or an approaching year Model 9 ?
I thank you by advance
what do you mean by valve lift?
the tappet clearance or the actual cam timing which is fixed?
Hi ! Thank you for your answer !
I mean by valve lift the "travel" of the valve between the moment it's closed and fully opened.
I'm making general controls on my new acquisition, and this mesure should give me an indication about the condition of the cams and cam followers :
Normally, the (what I call) lift is around the 1/4 of the valve diameter. So, it should be approximatively 11mm. I have mesured a bit more than 8mm.
But I know too that sometimes, for quiet engines, this value is lower, hence my question.
I'm not too concerned about the valve timing for the moment, as the bike runs nice, and the cams are specific to this model. But much more about their condition. This value would permit me to know if I have to open the timing case for further investigations, or to let it as it is for the moment...
what you need is valve timing diagram, I don't have one, if they ever existed that is, possibly someone here will, my advice to you is if its running well, don't worry about it, 90 yr old machines are not precision instruments.
If it ain't broke don't fix it.
There are otehr opinions,mine is the correct one ;D ;D ;D ;D ;D ;D
Thank's for your answer. Anyway, if some of you all had this very simple answer to give me, it would help me.
It is very likely such a diagram does not exist.
Thank you KJ, but for the moment I don't need such chart. I just want to check roughly the conditions of the cams and cam followers : if they are worn, there will be less valve lift.
By comparing my values to the other ones I hope to get from you all, I'll be able to appreciate their conditions. If mine aren't too far of the constated ones, I won't need to investigate further in that area.
The idea is to make an overall view of the condition of the bike, to see where I have to do something or not, apart the critical checks like the brakes, chains and so.
Anyway, I thank you to be concerned by my question, and I hope I'll have some answers to mine
Chris Odling may know. At this year's annual rally he gave a very impressive talk on the many cams and his tool room templates for remachining cams following building them out with stellit. He is a very busy man but you could make contact. Although your machine is faily rare.
Vic
Thank you Vic, I effectively saw the photos of the annual rallye, with the veeery interesting ones about cams and cam followers.
I've begun to be in touch with him, I'm sure something good will come from this.
As soon as I'll have some news and infos, I'll write there to share them.
Hi Claude..My 1932 30/60 cams are 6.5mm lift on the inlet and 7mm on the exhaust..The cams were rebuilt by Chris Odling this year, he also refaced the followers.
Hi Single Minded (we are all there I think..), a great thank for your answer !
Is yours a Model 9 too ?
If yes, it would mean that it's a very quiet engine !!
I succeeded to have a 9.5mm lift with the 38mm valve head diameter of my Royal Enfield WDCO, just by getting the rockers geometry spot on...
I'm very curious to have your answer !!
These cams are in my 9A 600cc and my M90 engine..After about 1933/35 the cams had more lift but kept the same timing.
Thank's ! Very interesting ! I've sent a message to Chris Odling, to have some informations. Since I'll have news, I'll share them