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#1 |
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Quite an interesting video. Reaching revs an SV owner can only dream of
![]() http://www.asphaltandrubber.com/bant...ves-14200-rpm/ |
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#2 |
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I cant see the valves open!
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#3 |
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thats incredable, doesnt even look like they are moving up and down at all! though at the end it looks like the spring is turning round, and thers much smoke/steam/oil somehting going on lol
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#5 |
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Wife just walked in, I'm sat there smiling like a Cheshire cat and she's like....WTF?! "You're looking at some metal making noise?".......wimmin
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#6 |
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I think the spring bits are supposed to move round so as not to get a wear point. Oil vapour I imagine, and that's what normally goes into the airbox and either gets burnt or condenses back.
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#7 |
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Does the BMW redline at 14 odd or Top out at 14?
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#8 |
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It's a standard development check to determine valve rotation vs engine speed to ensure satisfactory rotation. You don't want excessive rotation as it can lead to seat wear but you do want some rotation to take place during the normal engine speed range to maintain clean seats and good sealing.
You quite often see rotation reversal too, the graph of valve rotation vs engine speed can be a bit like a hockey stick, dipping negative then going positive as speed increases. The driving force behind valve rotation is the balance between spring helix angle and usually valve tip/follower friction. At low speed the tip friction will usually prevent rotation, as speed increases the inertia unloads the contact at full lift and rotation begins earlier in the lift cycle so rotation rates increase. For lower speed engines it's common to introduce low friction elements into the system in order to promote rotation at low speeds, first is multigroove collets which don't grip the valve stem (often only on exhausts), for very low speed engines positive rotators can be used ("rotocoil"). Interestingly the short pivoted finger follower as in this case is usually the lowest inertia design so most suitable for very high speed valve gear. Good game.
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#9 | |
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#10 |
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Has anybody seen the new Black Eyed Peas video? BMW S1000RR features
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