valve lash adjustment

I do not know the history of my motor, but I have run into a situation that I could use a little input on.
It is a Chevrolet 350. I had a noisy valve, and found I could
not adjust the lash on #7 intake. Long story short, I pulled the cam, and found the lobe to be extremely worn. In my approximation, 1/2 inch. Also intake on #5 was also worn, almost to the same extent. I bought a new cam, and have installed it. However, I am still unable to adjust the lash on #7 intake. With the cam and lifters being new, and all the push rods the same length, that only leaves the valve springs. All the rocker arms arms look good, and also the studs.
I know there are some good mechanical minds out there. I truly appreciate any thoughts anyone might have on the situation. Thanks, in advance.
Thanks, Ken 1970 C-10
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
earthlink newgroups wrote:

It's been awhile since I've worked on a Chevy, but just from your description, my guess would be that you have a couple of valves sticking. This would be causing the rocker arms to wear on the lobes of the cam, thereby causing the cam lobes to wear down.
I could be wrong, but the only solution I can think of is removal of the head to facilitate the removal of the stuck valves. You should be able to pick up a new set of valves, valve guides, and springs at your local auto shop since the Chevy 350 is an extremely common engine.
You may also want to check the rocker arms to make sure they are not warn from the sticking lifters. Don't forget to get a new head gasket since removal of the head will probably destroy the existing one.
Just my thoughts. Hope things work out for you.
Eric
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'd measure the height of the studs. I had one pull out of the head one time. Used to be fairly common.
--
Old Crow
'82 FLTC 'Pearl'
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I know from experience that it is possible that the nuts back off real easy if they are not changed at the same time. USE NEW LOCK NUTS. It was an expensive lesson for me on a "completely rebuilt every thing new engine". I've also had good luck with a rawhide mallet and a constant stream of PB Blaster shooting down the guides while persuading it not to stick a few hundred times, then a follow up with marvel mystery oil or risolene treatment. And by any chance did you heat and bleed the air out of the lifters before you put them in? I heat them up in a pot of oil on the stove, not hot enough to varnish, but you'll see the bubbles keep coming out. Good Luck

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Well, it turned out to be one of the studs had backed out. GM heads. I found it by placing a small ruler over a couple of studs. It was up about 3/8 of an inch. I put an old rocker arm nut on it, and whacked it back down. I just got the truck back together yesterday. And it runs AWESOME! Lots more power, and no more knocking noises. Thansk to all that had input. Ken

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.