Problem adjusting one exhaust valve

[goatee]

Trying to adjust the valve lash. Counting from the timing chain to the firewall I cannot adjust the third exhaust valve. No matter how far I go each direction it's way too tight. Any thoughts? I can't seem to get it loose.

[okayfine]

Not to rain on your parade and jump to the worst possiblity from the off, but you might have a sunk valve seat, which would bring the valve "up" as a result. I don't know how to verify that without popping the head off, or you may happen to have access to a bore scope.

Does adjusting it not change anything, or you just don't have enough adjustment to get it within spec?

[goatee]

Hmmm, well going which direction all the way should make it as loose as it could be? Could I try pulling down on the valve like when your putting on lash pads and see if it moves? Wouldn't my motor sound horrible if it was stuck?

I'd be more in line with I don't know what I'm doing more than something is broken.

[okayfine]

The valve would likely still move, but a sunk valve seat would get bashed further into the head and by consequence the entire valve would seat further into the head. The end of the valve would be higher than the others, and it'll get to a point where you can have the adjustment as loose as possible and there still won't be clearance for the feeler gauge at the rocker.

Now with your clarification, you should be able to figure out if the parts are turning and adjusting as they should. To be honest, it's been so long since I've had an L-series head to adjust that I've forgotten which way's what. One of the smarter folks'll be along shortly to clarify.

[goatee]

I'm going to head out and loosen one of the others so I know which way for sure, think it was clockwise. Then I'll try again.
Oh and to ask again if it really was sunk wouldn't something sound horrible or be gutless or something? Every seems to be running pretty good and I even just got back from a 180 mile drive on saturday.

[goatee]

Ok clockwise. After messing with it it seemed to come loose so to speak. I adjusted it, took it for a ride and look again real quick. Seems fine. I'll run it for a day or two and recheck it again. I still have a tick so something must still be on the loose side.

[datzenmike]

http://community.ratsun.net/topic/16539 ... djustment/

[goatee]

Cool thanks I'll watch it!

[banzai510(hainz)]

If you adjust the pivot post in all the way and still cant get the valve lash set cause the rocker is still pushed up against the cam. Your more or less done. Maybe thin down that 17mm jam nut so you can get the 14mm post to go down a little more. To sqeeze a couple thous out of it.

As okayfine said ,its the valve seat sinking thus pushin the rocker up.


One way to cheat the system is put a regrind cam or maybe add some cam tower shims.Either way your pulling the head.

My 521 recently had a head gasket proplem and I notice one ex valve getting close. So I put another rebuild Schneider cam head on so I dont have to do this again anytime soon.

[okayfine]

Oh and to ask again if it really was sunk wouldn't something sound horrible or be gutless or something?

Not until you ran out of adjustment and the seat continued to sink into the head. Otherwise you essentially just have one "tall" valve and have to remember it's out. You'll likely also have some funky rocker wiper geometry, but nothing that's a show-stopper, for the most part.

If your adjusted valve remains in spec after a few days and you still have a tick, perhaps you have an exhaust leak? At the manifold, they can be pretty loud and obnoxious. See how your first fix works.

[goatee]

Ok sounds good I'll try to post back what I find out.