Oh crap, Valvetrain
Thread Starter
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Oh crap, Valvetrain
I was cleaning up my AFR heads yesterday. I pulled all the valve to clean the heads and just check the springs. One valve get stuck on the way out. The rest just slide out. I had to tap it out. Upon further inspection the top of this one valve had mushroomed over and was .003 larger than the rest. Obviously it would not go back in. Looks like a new valve is in order and probably a new guide seeing as I probably ruined it on the way out. The rest of the heads look very good. There was nothing on the rocker (Comp roller tips) to indicate anything bad. Could it have been a bad valve. These only have about 6K miles on them. I'm taking it to the machine shop to have him check out the guide and proably put in a new one.
Safety Car
Joined: Oct 2000
Posts: 3,547
Likes: 12
From: Carbondale Pa.
I used to find that sometimes the very end of the valve stem would mushroom out ever so slightly and also the groove at the keeper grooves would nick the stem that the valve couldnt be removed, I used the finest tooth file I had to slightly dress the end until I could get the valve out. But of course if the valve was already out that would'nt help ya,,, but something to file away for future reference.
Peace,,, Moosie
Peace,,, Moosie
Race Director
Joined: Jul 2002
Posts: 11,593
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From: Clayton NC
Sounds like it got heated a bit, Let me guess number 5 or number 7 exhaust valve? Could it be that you could have run the motor a little lean at some point? Good catch man! I can't wait to get my AFR heads.. Dave...
Thread Starter
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
It was actually number 2 exhaust valve. One other exhaust valve was tight but it still slide out. The rest are all good. Come to think of it I think it was number 1 exhaust valve. Maybe the front of the motor was not getting enough oil? We will see, I'll have to keep an eye on it with the new motor.
Race Director
Joined: Jul 2002
Posts: 11,593
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From: Clayton NC
Originally Posted by Gordonm
It was actually number 2 exhaust valve. One other exhaust valve was tight but it still slide out. The rest are all good. Come to think of it I think it was number 1 exhaust valve. Maybe the front of the motor was not getting enough oil? We will see, I'll have to keep an eye on it with the new motor.
From what I've seen the only time you mushroom a valve stem like that is from the heat. You should have seen all my exhaust valve stems..
I had to file all of them down so I could pull them out of my heads...OOPPPS... Dave...
Instructor
Joined: Nov 2005
Posts: 207
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From: raleigh N.C.
I agree with the lash cap reccomendation but
you might want to check rockerarm geometry
I'm using .200 long valves but with lash caps,
the .300 long pushrods were needed
just make sure the contact area of the rocker
is centered over the valve at 50-60% max valve lift
good read
you might want to check rockerarm geometry
I'm using .200 long valves but with lash caps,
the .300 long pushrods were needed
just make sure the contact area of the rocker
is centered over the valve at 50-60% max valve lift
good read
