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You should have deleted the second picture as well. It's awfull. I'm curious how long the valves, the guides and seats will last. I hope I still haven't understood completely this concept, but to me it looks as if the adjuster screw balls will not only move the valves up and down, but also to and fro. Tell me I'm wrong.

 

Hubert

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You should have deleted the second picture as well. It's awfull. I'm curious how long the valves, the guides and seats will last. I hope I still haven't understood completely this concept, but to me it looks as if the adjuster screw balls will not only move the valves up and down, but also to and fro. Tell me I'm wrong.

 

Hubert

 

Why so? All rockers will impart a side load on the valve stem. This system which has the sort of 'Ball and Socket' hip joint on the end of the adjuster is simply a kind of inverted lash cap as afar as I can make out. I'd think it had been done to minimise the side loadings raher than the opposite? The earlier Hi-Cams are very hard on their guides. I thought this might of been a system adopted to combat that?

 

pete

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You should have deleted the second picture as well. It's awfull. I'm curious how long the valves, the guides and seats will last. I hope I still haven't understood completely this concept, but to me it looks as if the adjuster screw balls will not only move the valves up and down, but also to and fro. Tell me I'm wrong.

 

Hubert

 

looks bad to me too, the short radius rockers cannot be good.

 

Pete how does this ball and socket system mitigate the side loading? :o

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looks bad to me too, the short radius rockers cannot be good.

 

Pete how does this ball and socket system mitigate the side loading? :o

 

By resolving the rotating and sliding forces separately. The ball-joint enables the flat pushing against the valve stem to distribute all pressure evenly across the end of the valve stem. The side to side sliding forces are similarly evenly distributed, instead of being a point load that breaks down the oil film. So the side loads are potentially the same, it's just that the friction between the valve stem and ball-joint end of the rocker arm is reduced such that less of that load ever reaches the valve stem to put wear on the guides.

 

Basically, someone at Moto Guzzi finally went down to the corner speed shop specializing in the old flat-four air-cooled VW Beetles where they've been in use since about the time the V7 first hit the street and took some notes... :luigi::nerd:;)

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By resolving the rotating and sliding forces separately. The ball-joint enables the flat pushing against the valve stem to distribute all pressure evenly across the end of the valve stem. The side to side sliding forces are similarly evenly distributed, instead of being a point load that breaks down the oil film. So the side loads are potentially the same, it's just that the friction between the valve stem and ball-joint end of the rocker arm is reduced such that less of that load ever reaches the valve stem to put wear on the guides.

 

Basically, someone at Moto Guzzi finally went down to the corner speed shop specializing in the old flat-four air-cooled VW Beetles where they've been in use since about the time the V7 first hit the street and took some notes... :luigi::nerd:;)

 

I wasn't aware of the old Vee-Dub connection :lol: . Your explanation confirms what I saw as the point of the whole thing though. I don't think the rockers are an isse either. Yes, on the earlier Hi-Cams which use a system that is very similar, (In fact in most ways the *new* valve gear and the *old* valve gear are practically identical.) there was a problem with rockers snapping but only under very extreme conditions and high revs. Not only does the new motor use different springs but all the earlier Hi Cams were built at 'One of those times' when quality control was less than peachy at Mandello. There was n outbreak of 2V rocker breakages at much the same time. Coincidence? maybe, maybe not....

 

Pete

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By resolving the rotating and sliding forces separately. The ball-joint enables the flat pushing against the valve stem to distribute all pressure evenly across the end of the valve stem. The side to side sliding forces are similarly evenly distributed, instead of being a point load that breaks down the oil film. So the side loads are potentially the same, it's just that the friction between the valve stem and ball-joint end of the rocker arm is reduced such that less of that load ever reaches the valve stem to put wear on the guides.

I think you have a bit of a trade-off here.

There would be some improvement from the more evenly distributed force, and maybe less wear at that contact point, but if it slid at the contact point, rather than being locked into a ball joint, I would think less load would reach the valve stem and guide, but if you lock in the force from the ball joint the valve is going to follow the arc and put more side load on the valve stem and more load and friction on the valve guide, right? or am I missing something.

(was that a run-on sentence)

Maybe roller rockers will be a hot selling upgrade for this bike.

In any case, I think a short radius is bad, but maybe it has less lift??????

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By resolving the rotating and sliding forces separately. The ball-joint enables the flat pushing against the valve stem to distribute all pressure evenly across the end of the valve stem. The side to side sliding forces are similarly evenly distributed, instead of being a point load that breaks down the oil film. So the side loads are potentially the same, it's just that the friction between the valve stem and ball-joint end of the rocker arm is reduced such that less of that load ever reaches the valve stem to put wear on the guides.

 

So the mini-bucket is a loose fit and slides about on the top of the valve stem? Have I got that right Skeeve?

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Could it work as indicated on this picture?

 

4vslideruc9.jpg

 

Why is this offset there? Is it a manufacturing problem or more a photographer's thing?

 

If you talk about Beetles: are you sure that the adjusterscrews were placed at the valve shafts? I think it was the same principle as on every other push rod driven engine. Simple question: how would the pushrods be fixed/centered without this ball joint?

 

Hubert

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So the mini-bucket is a loose fit and slides about on the top of the valve stem? Have I got that right Skeeve?

 

That's the idea. It's actually part of the adjuster screw [on a VW, you just replace the stock plain adjusters w/ those from an a/c Porsche], and valve lash is measured between the end of the valve stem and the flat on the end of the ball-end adjuster.

 

In answer to Dlaing's note: yes, roller rockers are another solution to the problem. Only, it requires replacing the entire rocker arm w/ a different unit; this ball adjusters are as stated above, more of an item that can be retrofit to an existing part system.

 

In all honesty, I only learned about these things recently when I was doing some research into VWs [been feeling nostalgic for my 1st cage lately, a 1960 Kombi w/ the later 1500 single-port engine. I didn't really care/know about the go fast stuff back then, but realized that there would be NO WAY I would want to give up all the performance of my more recent cars if I went back to the old mini-bus, so I was looking into what mods would be reliable and productive should I ever choose to go down that path again... Fun reading, basically! But, educational, to say the least... ;)

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