New Heads and Cam...
Thread Starter
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Seasoned HDF Member
Joined: Mar 2010
Posts: 21,117
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From: Poolville
I raced it up at ESTA Dragway in central New York. After Dyno tuning it, I forgot about the rev limiter that was set to 6700 rpm.. My bad, live and learn.. Hit the rev limiter a couple times. In my data logging I saw it hit 6850 several times.. I normally have it set to 6200 but I wanted to see what it would do on the Dyno at 6500..
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Joined: Dec 2005
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From: poway
I raced it up at ESTA Dragway in central New York. After Dyno tuning it, I forgot about the rev limiter that was set to 6700 rpm.. My bad, live and learn.. Hit the rev limiter a couple times. In my data logging I saw it hit 6850 several times.. I normally have it set to 6200 but I wanted to see what it would do on the Dyno at 6500..
With the valves seated what is the distance between the edges of the 2 valves?
It's a Tman cam?
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Joined: Aug 2018
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From: New Hampsha
My guess is over-revving caused the valve float and the piston hit it. Once it is hit, it can stick in the guide, and the next time it's supposed to open the support plate breaks instead. (Although I'm not clear on how that would work.) Must be pretty strong pushrods...
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
Last edited by John CC; Sep 7, 2024 at 07:23 PM.
Road Master
Joined: Jan 2024
Posts: 808
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From: Trinidad
My guess is over-revving caused the valve float and the piston hit it. Once it is hit, it can stick in the guide, and the next time it's supposed to open the support plate breaks instead. (Although I'm not clear on how that would work.) Must be pretty strong pushrods...
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
Stellar HDF Member
Joined: Aug 2018
Posts: 2,407
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From: Milwaukee, WI
Did you use new fasteners? Wondering if you got some stretch? Were the bolts still tight? It kinda looks like it lifted, and then cracked.
Did you have any backfire?
valve to valve damage to both, valve to piston will damage to both, all the rings intact?
Did you have any backfire?
valve to valve damage to both, valve to piston will damage to both, all the rings intact?
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Seasoned HDF Member
Joined: Mar 2010
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From: Poolville
Overrevving is not going to bend a valve unless the valve hits somethinig.. Heck I had my 113 evo set to 7000.. 170 lb triple springs and 640 lift cam.. First 20000 I used to bang the limiter. Not hard in first gear at the track until I started short shifting first..
With the valves seated what is the distance between the edges of the 2 valves?
It's a Tman cam?
With the valves seated what is the distance between the edges of the 2 valves?
It's a Tman cam?
Yes T-Man 660PS-2
My guess is over-revving caused the valve float and the piston hit it. Once it is hit, it can stick in the guide, and the next time it's supposed to open the support plate breaks instead. (Although I'm not clear on how that would work.) Must be pretty strong pushrods...
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
[Edit] Is the bolt in the upper left of the photo loose? How did that happen? Is that the valve that stuck?
Yes both bolts on that side of the Rocker plate loosened up as well as the 2 corner bolts for the lower rocker housing.
Yes that is the valve that had the damage but never stuck, it still moves very freely in the guide.
No all 4 bolts were loose on that side of the head.
I definitely believe the loosening of the bolts contributed to the current issue, it did lift..
No i didn't have any backfires..
I never pulled the pistons because I initially didn't see anything that indicated any P/V contact. Also after i replace the cylinder head with my Stage II heads my leak down test went from 38% to 6%. I believe my initial ring gap was .026" top and .022" 2nd... So i don't believe there is any damage to the rings..
Again I'm pretty certain that where the valve is bent could only be caused by either V-V or V-P.. But I could not find any witness marks to confirm which might have happened.
In the following link that I posted about the heads and valve clearance you can see that the rocker geometry was way out, I still believe that this was the issue with the bolts loosening up causing the whole situation.
Valve To Piston Clearance... - Page 3 - Harley Davidson Forums (hdforums.com)
Tourer
Joined: Oct 2010
Posts: 406
Likes: 241
From: NW MO
If the components flexed and lifted at higher rpm, lifters took up the slack, then when components unflexed at lower rpm, the valves would be floating and interference happened. Doesnt matter much if V/V or V/P at this point
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Road Master
Joined: Mar 2012
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From: Ohio
This