Engine: question about adjusting valve clearance

[roman.powell]

I'm attempting to adjust the valve clearance on my 1964 289, which I have never done before. The engine is cold, the rocker covers have been removed, and cylinder #1 is at top dead center on the compression stroke. I want to set the clearance to 0.026" (the middle of the range), but I can't even get a 0.010" feeler gauge, the smallest in the set I'm using, into the gap on either valve.

Is this normal, or am I doing something wrong? It seems like a pretty big change to make, so I want to check with all of you first.

[Mike Van Veghten]

This where the "adjustment" part comes in..!

Now you use an open end wrench to "adjust" the valves.
Turn the nut just above the push rod (actually part of the rocker arm !) to make the push rod looser. Continue to turn the nut until you can insert the .026" gauge between the valve tip and the rocker arm pad. It should be a snug, but free movement of the gauge with just two fingers holding the feeler gauge leaf. Smooth is the key. Not so loose as the gauge has no friction between the valve tip and the rocker arm pad. In this case, some friction is a good thing.

There are many ways to bring each rocker arm to it's adjustment point. You can look that up of have another explain it.

As you have done, cold and engine off, is the most accurate method of adjusting the valves. Others have their methods, but this IS the most accurate method.

Mike

[Dwain G.]

If you try to move the rocker arm up and down and find there is no slack at all, you are probably on #6 cylinder. You also would not be able to spin the pushrods with your fingers. Rotate the engine one full turn to the udc mark and see what you have for clearance then.

[roman.powell]

Thanks for the input, guys. I figured out what I was doing wrong. There's kind of a bump at the top of the spring, and I was pressing the gauge into the side of it, rather than finding the gap above it. I guess I didn't have enough light to see what I was doing. Once I figured that out, it went pretty well. Only one or two were really out of adjustment, and it idles a little more smoothly now. Someone marked the harmonic balancer every 90º, which is really handy.

[doofus]

Any time worn rocker arms are suspected use the Mini feeler gauge set they are the right width to set into the wear pocket an the rocker arm,once that's done you need to figure out why the rockers were starved for oil. BTDT. Luck Doofus

[altair]

On my 259 I adjusted the tappets at least 5 times before I was satisfied and they still clatter, I guess that is just how they are.

[studegary]

On my 259 I adjusted the tappets at least 5 times before I was satisfied and they still clatter, I guess that is just how they are.

I wouldn't describe it as "clatter", but they should not be silent. They are mechanical, not hydraulic operated.

[dstude]

Correct, the "clatter" is normal. The engine has solid lifters, not hydraulic lifters, and should always have a nice, soft typewriter sound when the engine is running, similar to the sound of early high-performance Corvette engines which also used solid lifters. It's a wonderful sound!

[studegary]

Correct, the "clatter" is normal. The engine has solid lifters, not hydraulic lifters, and should always have a nice, soft typewriter sound when the engine is running, similar to the sound of early high-performance Corvette engines which also used solid lifters. It's a wonderful sound!

I wonder how many of us reading this even remember what a typewriter sounds like.

[bensherb]

Correct, the "clatter" is normal. The engine has solid lifters, not hydraulic lifters, and should always have a nice, soft typewriter sound when the engine is running, similar to the sound of early high-performance Corvette engines which also used solid lifters. It's a wonderful sound!

I adjusted the valves on my R1 when I had the engine out of the car. Before I removed it the engine was silent, but I figured it's out of the car and easy to do, and who knows when they were last adjusted. Now back in the car it is what I'd call fairly noisey. I guess it is now normal?

[StudeRich]

I adjusted the valves on my R1 when I had the engine out of the car. Before I removed it the engine was silent, but I figured it's out of the car and easy to do, and who knows when they were last adjusted. Now back in the car it is what I'd call fairly noisy. I guess it is now normal?

That depends on whether you had to tighten them or loosen them, and how much.
If they were quite a bit tighter than .024 Hot or .026 Cold, then that explains why they were so quiet.

[Jerry Forrester]

It's a wonderful sound!

I agree. I love the sound of solid lifters when adjusted correctly. Not so much if one is a little loose. That sound grinds my gears.