Can somebody with experience of the Ducati 2 valve engine, please advise me, a novice on these beauty's... With the camshaft end cap off, would there normally be end play in the camshaft, eg does the end cap take up the lateral free play ? Also, does this end cap need to be fitted to enable valve set up/ adjustment.. ? Thank you..
I wouldn't have thought that there would any endfloat on the camshaft, or at least it would be shimmed for a minimum. The end cap is only a cap and will have no effect on it and as the end of the camshaft runs in the head, which serves as a plain bearing, the valve adjustments can be made with the cap off, unlike the earlier engines which have a bearing in the cap supporting the camshaft.
On the pre 1998 engines, there should be a 0.5 thou shim on that end of the camshaft, so on that basis the end of the cam can't touch the cap, however, there is a bearing in the cap on those engines as Derek says. When the middle and pulley side bearings are pulled up tight by the pulley nut, then the cam can't actually move sideways, so if you have a lot of play, then I suspect you have a spot of bother........Try checking the tightness of the pulley nut. AL
Give just dug out the cam covers and fitted one back on the said horz head and the plays all but gone (4 thou ) remains... ?
What bike and which year engine is this? I'm trying to work out where the cam bearings are fitted, because if they are situated in the same locations as the carbed SS (the middle bearing and pulley bearing), then the end play can only be two things......silly nut not tight enough, or actually in the bearings themselves. See the pic below........You can see if the two bearings are pulled tight by the nut, the cam can't move. AL.
The pulley nut I've checked and it's tight and up to torque ... It's a 2010 796 Hypermotard Posted parts list
Can't see the bearings in your image, so I don't know if they are locked into postion like my quick drawing shows......But anyway, if it is in the bearings it is probably because they will be 'C3' grade and there is more clearance in that grade than in ordinary bearings. But from what you say, if fitting the end caps has taken up the end float and assuming the end caps are aluminium, maybe I'm wrong but I find that a bit disconcerting as they aren't really suitable for having a cam rubbing against them instead of a thrust washer.
Yes friend that's exactly the thought I had.. The vertical head is still intact as it was when removed from the engine.. I will remove the valves from that tomorrow, so it's in the same state as the horizontal head, and see it that has end float .. At the moment the vert head has the cam cover on, but unlike the hor head has all the valves assembled.. at present this has no end float.. So perhaps by doing that it will tell us something..
It would be interesting to actually see how the bearings are located in the head because from your images, it looks as though there only two, one on the cap end of the cam but where is the other one? As it stands, looking at your image, the only thing that could alter any end float is the washer thickness Item No.20.....IE a thinner washer would pull the cam nearer to the pulley...... Anyway, see how it goes. I'm not a million miles from you, and I may out on the bike tomorrow.
That's kind of you.. I'm on nights tonight, but if your out near by please call me and i will make a cuppa and have a look.. N@@DS
Al, As I understand it there are no bearings. The cams run directly in the head which itself acts as a plain bearing. Hence no bearings shown on the parts diagram. So when the silly nut is fully tightened there will have to be some play or the camshaft will bind on the head. But I would expect that play to be very little and wouldn't expect the end cap to be required to prevent endfloat. I've done valve adjustments on a couple of these engines but never had an end cap off, so what Noods is seeing might be normal.
Derek and Al.. I've just had a quick look at the vertical head which is yet to be dismantled, pictures below.. Very little end play in it until you take off the cam cover, then you have the play.. Seems like a crazy idea to me.. The only thing between the end of the camshaft and the inside of the cover is oil, hopefully .. The cover is alloy and the end of the cam steel... Not the best combination I wouldn't have thought..
It looks like there is a witness mark on both those end caps where the cams have been touching.......Perhaps the end caps are a service item, IE chuck away and replace. But steel cams running in aluminium and not in bearings and / or without some sort of thrust washer...... Perhaps Italian ally is far better than any ally I have come across..... Maybe it's time to ask a friendly Ducati dealer workshop (MotoRapido, say) or grab a workshop manual.
I've been trying to find a workshop manual for years for one of these, there just doesn't seem to be such an item available to us... I will ring moto on Tues and see what they say...
That set up is common practice in the automotive engine industry, cam runs directly in the head and caps (no separate bearings), and either a cam journal or end cap controls end float. I have seen engines like this with more than 400,000 kms on the clock and still be fine.
Oh well, that's maybe the answer Noods needs.........so do the valve adjustments with the endcaps on.
Well the cams run directly in the head in all the Testastretta engines. I'd never heard of an end cap controlling end float before though.
Checked with Mark, technician at moto rapido today and yes that's how it is... The cover cap takes up the play..
