help with valve adjustment

[dwjack]

I was getting some noise from my lifters so I tried adjusting my valves. I rotated the engine to TDC and adjusted the valves according to my chilton. I tightened the nut until I couldn't spin the pushrod and then tightened it one full turn. The book called for 3/4 to 1 1/4 turns. Then I spun the engine one time around and did the rest of the valves.
After that when I tried to start the engine it wouldn't start and it sounded strange while cranking. I took the valve covers off and backed all the nuts out one full turn and it fired right up. I don't feel the I have adjusted anything.
What am I doing wrong?

[swervin ervin]

I never, ever, tighten my rocker nuts over 1/2 turn. Some folks have said they would loosen up on them over time. The only reason this happens is because the nuts are worn out. Anyway, I like to use the firing order method to do my adjustment. It's a tried and true method that works every time without fail as long as you keep track of which cylinder you are working on. You will need timing tape or a degreed balancer for it though. You can also mark the balancer at 90 degree intervals to do it too.

Read this article I wrote a long time ago about this. It's very possible you have some valves too tight. If so, it will never start. It will only start if the valve can close and create compression.

http://www.73-87.com/7387garage/drivetrain/valvlash.htm

[us111]

hello,,,i hope this link works that i'm gonna try,,lol..best advice along with swervin's that i have used...


http://www.2quicknovas.com/happyguides.html

[hobbz]

if you don't care about cleaning up your engine bay a lil, you can start the truck up, let it warm up all the way. then remove the valve covers and tighten up the nuts until there is no more noise and the rockers don't wiggle side to side.

maybe not the most exact method but it works in a pinch...

[swervin ervin]

Adjusting the lifters with the valve cover off and the engine running is a total mess. You can cut a old valve cover so it don't splash so bad but it still goes everywhere, especially if you have a higher pressure/volume pump or even good oil pressure. Besides, it's not a good way of doing it in the first place. The lifters need to be empty, or in other words not pumped up as they will be with the engine running.

What the objective of the whole deal is, to center the pushrod in the center of the lifter. This is why GM recommends going 1 full turn past zero lash. They have tested this from the very beginning and found this centers the pushrod. Reason all performance guys go 1/2 turn is to increase our upper RPM range before floating the valves. Floating the valves simply means the lifters pump up with oil and open the valves earlier. So, the 1/2 turn margin gives us a margin for a few more revs.

Now, after saying all this, I have also adjusted mine that way before, many, many, years ago. This was before I found out it wasn't the correct way of doing it (and didn't care about the mess). Of course the companies who make the little shields you clip on the rockers to help stop the splash would go broke if everyone knew better.

Mike

[benoit454]

I don't see that method as being the wrong way. My dad done it to every motor he ever rebuilt. In his lifttime he has rebuilt countless engines and worked for over 20 years at the local goodyear tire store as shop manager and mechanic and done countless engines there. He hates the method of doing them with the engine off and says he doesn't think it would work. I always do mine that way. I go anywhere from 1/2 to almost 3/4 turn after zero lash. I also do mine before the lifters are pumped just as you said. I like it that way. Cleaner, and easier I think. My dad had them valve covers with holes drilled for each one to do it with it running, then we bought the oil stoppers and used them, one or two always flop off though and oil gets throw. The old 76 had a high volume pump and slung oil upwards bigtime.

But he swears by the engine running method, back em off til they start ticking, then tighten them til they stop making noise, then go half to 3/4 turn. that's how he always done them, no problems that I ever seen or anyone else had or seen.

I'll stick to the non running way though.

[dwjack]

Thanks for the help,
I used mikes method to readjust them and the truck is running good but the noise is still there. There is no noise when I take off from a stop it's when I let off the gas and then get back on it, it sounds like marbles ratteling around in the engine. Could this be spark knock I'm hearing?

[swervin ervin]

Yes, it's pre ignition (spark knock). Check your timing.