my guess is its broken at the position that is just below the end of the guide. a non concentric (worn seat) causes additional eccentric loads that bend the shaft whenever the valve closes. after alot of cycles it fatigues, 300k is alot of cycles if they are original valves
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Loud metal clash while driving, no longer starts
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89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
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Originally posted by digger View Postmy guess is its broken at the position that is just below the end of the guide.
All the reused valves were ground. All 12 valve seats were cut by a machine shop.
I've heard the term "lapping the seats" but did not perform this. Another regret.
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could it also be that there was piston to valve contact and thats why it broke?89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...
new build thread http://www.r3vlimited.com/board/showthread.php?t=317505
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