Exactly ! Sometimes the P rod jumps it's socket,moves inward on the rocker and the change in ratio causes the valve to open too far making HARD contact with the piston and bending the p'rod at the top ,like yours did . Intitially it all likely started with a tight stem to guide . Ian Adkins wrote:
Likely right Gary,
I have seen a Loop engine go from 4000 rpm to zero in about 1/3 a second. Turns out that the engine seized because of no oil in the bike. When the engine was torn apart the only thing that caused the seized was a small contact patch on the main bearing that fused to the crank. Amazing forces at play.
I am starting to think that the valve seized open.....subsequently getting wrapped by the piston. It not only bent the valve but pushed it back. While this was going on the excessive clearance on the rocker caused the rocker edge to get on the edge of the cup of the push rod. Somehow the rod got bent in the process.
OK....so what caused the seizing in the guide?
-----Original Message----- From: Gary Cheek [mailto:kg8-@comcast.net] Sent: Sunday, March 21, 2004 1:22 PM To: Loopfram-@topica.com Subject: RE: Ambo/Eldo head compatibility
Ian , The guide siezed first . Push rods don't just "bend" where yours was bent.We saw a lot of that stuff at Utica Cylinder head . Look back at the posts leading up to yours. I hope you can find a competent head shop down in Geawgeia . Ian Adkins wrote:
Hey All,
Was wondering if I could bolt on my Eldo heads from my Police project while I repair the head from the Ambo?
Intake valve was indeed bent. Needed to hammer the thing out. From the looks of it the valve could have fused to the guide (since there was some brass tightly fixed to the valve stem) and that is what kept it open...allowing the piston to hit the valve and bend it. Not sure if this is the case because the valve was closed when I pulled the head.
I'm still not sure which was first to go. The push rod bending causing the valve to bend (see previous email explaining my theory) or vice
versa. A
bit of a mystery. Possible there was a lack of flow of oil to the top end too but there was lots of oil up top when I initially pulled the rocker covers.
Not sure whether to look for something else. At any rate I am happy in some ways because I think the damage could have been considerably worse.