Dr H Posted July 13, 2014 Posted July 13, 2014 Christ! They are well a truly buggered..... What could have caused that to happen on just one cylinder?
Martin R Posted July 13, 2014 Posted July 13, 2014 Piston, valve interface is the term i believe? On the bright side the valves are still attached.
Dr H Posted July 13, 2014 Posted July 13, 2014 Piston, valve interface is the term i believe? On the bright side the valves are still attached. Yeah I know that! What I meant was what has given way to cause it on just one cylinder. Obviously not a cam belt / chain slip. Something failed in the piston / rod?
danwebster Posted July 14, 2014 Posted July 14, 2014 Most likely valve cap or spring, possibly the tip of the valve. Do you know what poundage the valve springs are? One of the above coupled with rpm I should add.
jonnyfox Posted July 14, 2014 Author Posted July 14, 2014 Yes, Frank reckons cam timing but I'm with you Dan.
danwebster Posted July 14, 2014 Posted July 14, 2014 Actually, looking at the picture again he's probably right...both the valves have twatted the piston. I wonder what kind of clearance they were running.
jonnyfox Posted July 16, 2014 Author Posted July 16, 2014 Did the head of the valve fall off the stem, the stem is straight, the other stem is bent with the head still attached....
Alex B Posted July 16, 2014 Posted July 16, 2014 looks messy jonny.will the s1 be taking a trip to Le Mans?
danwebster Posted July 17, 2014 Posted July 17, 2014 Yep you've pulled the head of the valve - hence me asking what poundage your valve springs are. If you run loads of revs and monster springs this is exactly the kind of issue you risk. I'm sorry to say that you need better quality valves than you're currently running.....give me a call if you want a chat about any of it...I have some experience of the ones you pictured previously.
jonnyfox Posted July 17, 2014 Author Posted July 17, 2014 Will do Dan as soon as the breakdowns complete mate
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