valve rotation ?
02-02-2008, 03:37 PM
#1
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valve rotation ? Given the LS valve locks clamp the valve....do the valves rotate at all during use ?
Reason I ask. Is that there are noticable rocker arm marks on the top of my valves. Except the wear pattern isnt just visible where the roller is against the valve....but at different positions as if the valve has rotated at some point.
I thought a clamped valve wouldnt rotate ? And if it shouldnt....why has it ?
Ive only about 1000 miles on this engine, most of which were running in, and the latter few some 20-25 dyno pulls to a little under 7000rpm.
232/240 on 115LSA cam circa 600thou, TFS 225cc heads, and 1.7 YT Ultralights and Morels.
Everything new.
Reason I ask. Is that there are noticable rocker arm marks on the top of my valves. Except the wear pattern isnt just visible where the roller is against the valve....but at different positions as if the valve has rotated at some point.
I thought a clamped valve wouldnt rotate ? And if it shouldnt....why has it ?
Ive only about 1000 miles on this engine, most of which were running in, and the latter few some 20-25 dyno pulls to a little under 7000rpm.
232/240 on 115LSA cam circa 600thou, TFS 225cc heads, and 1.7 YT Ultralights and Morels.
Everything new.
02-02-2008, 11:14 PM
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There was a great video posted a while back, a high speed (but slow motion) camera showing a valve spring running at high RPM. Interesting thing was the spring would spin. I think it was posted by yeahdoug (PAC spring expert). If the spring spins maybe the valve does too.
02-02-2008, 11:27 PM
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Here is the link, the movies are at the bottom of the page:
http://www.racingsprings.com/Pictures.htm
http://www.racingsprings.com/Pictures.htm
02-03-2008, 07:11 PM
#6
What is wierd is that the springs and valves appear to be rotating regardless of whether the valve is static(closed postion and rocker arm not acting on the valve stem) or it is being opened by the rocker. You would think that if the valve and spring were constantly rotating as it appers to do that the parts would were out. The valve faces and seats would wear. The springs, spring seats, retainer, keepers and valve stems would all wear if all these parts are constantly turning. Somehow this doesn't seem to be the case even though through the video it is clear that all these parts are rotating. Hard to explain.
02-03-2008, 07:18 PM
#7
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Thread Starter
I was under the impression valve rotation did happen...and was to reduce wear on the valve face and valve seat.
Although that would be on setups where the valve locks dont actually grip the valve, and allow it to rotate.
But how it occurs on those videos, and setups with locked valves....is hard to understand.
Although that would be on setups where the valve locks dont actually grip the valve, and allow it to rotate.
But how it occurs on those videos, and setups with locked valves....is hard to understand.
