I think I stuck a valve
#1
So, Sunday I was running around 5200 RPM'S. I heard the starboard engine backfire/pop. I pull the sticks back and hit the kill switches. I turn the engine over and here some ticking under the inside valve cover.
I finally got around to investigating today. It appears I stuck a valve and then my pushrod deflected and broke my Dart adjustable guides. Pushrod is still straight as an arrow. So what came first? The chicken or the egg?
I have been spinning these to 6500 RPM'S for years. Last year I put in me cams and ram them all summer with no issue. Shoot Friday I ran them 50 miles at around 4000 RPM'S.
[ATTACH=CONFIG]525169[/ATTACH]
[ATTACH=CONFIG]525170[/ATTACH]
I finally got around to investigating today. It appears I stuck a valve and then my pushrod deflected and broke my Dart adjustable guides. Pushrod is still straight as an arrow. So what came first? The chicken or the egg?
I have been spinning these to 6500 RPM'S for years. Last year I put in me cams and ram them all summer with no issue. Shoot Friday I ran them 50 miles at around 4000 RPM'S.
[ATTACH=CONFIG]525169[/ATTACH]
[ATTACH=CONFIG]525170[/ATTACH]
Last edited by Rookie; 06-25-2014 at 07:36 AM.
#3
Damn Jason , second time for this isnt it? Never stuck a valve in a BBC ever, had valvtrain probs when I used Comp cams rockers and polylocks with rocker nuts splitting and backing off but thats it. I have since went to T/D shaft rockers, Smitty
#4
My thoughts are the valve hung in the guide, then the push rod deflected and broke the guide plate. I would not trust that push rod any more. Your cylinder head machinist will tell you better, but I am thinking that since it is an exhaust valve, it is more than possible that water got on that valve, causing it to bend up. I think you were really lucky the valve didn't break off and cause catastrophic damage. While its apart, I would pressure check the exhaust for any leaks. If there are no signs of water, its possible the valve simply hung in the guide.
#6
Valako's gong to give me his assessment today after he goes through all of the evidence.
My thoughts are the valve hung in the guide, then the push rod deflected and broke the guide plate. I would not trust that push rod any more. Your cylinder head machinist will tell you better, but I am thinking that since it is an exhaust valve, it is more than possible that water got on that valve, causing it to bend up. I think you were really lucky the valve didn't break off and cause catastrophic damage. While its apart, I would pressure check the exhaust for any leaks. If there are no signs of water, its possible the valve simply hung in the guide.
Also, on the valve not breaking. I smacked 3 valves previously during my last bout. The Ferrea's have been holding their own against the pistons. lol
On the bright side everything under the intake manifold looks great!
Last edited by Rookie; 06-25-2014 at 07:56 AM.
#8
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You are right that several of the chambers look steam cleaned like there was water getting into them, but the #1 chamber does not look that way - and that is the one with the stuck valve. You may have more than one issue going on.
#9
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From: On A Dirt Floor
#10
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Joined: Jul 2011
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From: Ft. Worth TX
I agree seems always to start at the top edges of the piston(s) then moves downwards. Also looks likes a very mild form of it on another piston. I would also look into timing, fuel, octane, spark plugs and heat causing detonation issues.



