Valvetrain issues
Thread Starter
Race Director
Joined: Oct 2002
Posts: 12,065
Likes: 2
From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Valvetrain issues
Sunday I had a show in Kansas City. On the way home, the car started popping out the carb at anything over idle..at first I thought it was simply an exhaust leak. I got the car home and put it away for the night, tired of dealing with it for the weekend. When I got home today, I popped my left valve cover off and found the #3 intake rocker arm canted slightly forward and could see the top of the valve. I called the guy that built my heads to have him come over to see what he thought. He felt that the valves on the left side of the engine were way too loose. I noticed that the thread protrusion on that rocker arm was about 1/2 of what the others showed. As near as I can tell, the nut backed off.. not uncommon for a self locking nut to do that. i have seen it happen where the nylock in it has failed on aircraft before. I undid the rocker arm and found the push rod bent. I am going to change the push rod and nut and readjust the valves. Do I need to do anymore?
Drifting
Joined: Sep 2004
Posts: 1,532
Likes: 4
From: Fairview Heights Illinois, near Saint Louis MO, STL C3 Shark
Your probably fine. My guess is the rocker got loose and the push rod got out of alignment and then got bent. I've heard of folks using double nuts on the rocker studs to keep them from backing off, but I've never had the problem.
Instructor
Joined: Jan 2005
Posts: 159
Likes: 0
From: Chardon Ohio
Had the same problem you described just a month ago. Found out that I had a defective cam and had a lobe that was completely wiped. Had to replace the cam. Was the opportunity to go a little more aggressive with the cam.
Thread Starter
Race Director
Joined: Oct 2002
Posts: 12,065
Likes: 2
From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
it's an old cam.. new lifters due to new top end, but i hope that it isnt a lobe issue... judging by the amount of the threads that the nut was backed off, i would say that was the culprit...
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