I was cleaning the valve cover the other day when this little voice reminded me that B18's should have the valve clearance adjusted about every 8,000 miles. (I must confess that I have never done this in all the years I have driven B18's) Anyhow, I get out the feeler gauge and set the valves per the Clymer manual at .020 (I was surprised that some of the valves had NO clearance at all), and low and behold I now have tapping sounds. Removed the valve cover again and repeated the process - found a valve or two that was a little (.022) loose. Tapping is much better, but still there.

Three questions come to mind:
1. How often should the valve clearances be checked?

2. What is the best setting for the valves?

3. How tight should the retaining nut be on the valve adjustment screw?

Any help will be appreciated.

Oliver
1966 B18B (1800S)

One other thing worth checking is the surface on the rocker where it contacts the valve stem. If there is a hollow worn in the rocker the feeler guage sits across the high spots and gives an innacurate reading, resulting in an incorrect ( excessive ) clearance setting.
Colin.

...good call Colin. A full width feeler gauge will bridge any gap worn into the rocker surface, and add the wear depth to the feeler, for a larger gap. My solution is to grind down the .016" feeler to a width a little LESS THAN the width of the valve stem (don't forget to deburr). This helps to get an accurate setting.

Cheers

Are you SURE that each valve was completely closed before you tried to
set its clearance? If the valve was lifted or starting to lift you will
get a LOT more than 0.020" clearance.

BTW the correct clearance for a B18 engine is 0.018". B20s and B30s need
a little more because of different valve stem size and other factors.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

George,

Thanks for the response. If I am reading the book correctly, then with the number one cylinder at TDC on the compression stroke, the #1,2,3,5 valve should be adjusted. This would also have the valve completely closed. I did notice that if you rock the crank pulley just a little bit either way (2-3 degrees), one or more of the valves would move slightly. I guess that could cause a incorrect reading on the feeler gauge.

Thanks

Oliver

What I usually do is to put the car in top gear and roll it, watching the
valve close and after it closes, roll it a bit further.
Every time I set a valve I mark it with chalk so I know where I stand.

Since the lift at the valve is about 0.375 and the clearance is 0.020,
a very small amount of lift will really screw up your clearance.
I'd turn the crank more than 2-3° to make sure the valve is closed because
there is a bit of a ramp that may last longer than that. You want to be
on the sure-'nuff HEEL of the cam, not anywhere near the lobe.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

Thanks for the tip.

Now what about questions #1 and #3?

How often should the clearances be checked?

How tight should the adjusting nut be on the adjustment screw?

From looking at a cam I've come up with an easy technique to guarantee you are setting the clearance on the cam opposite the lobe. Turn the engine until a valve depresses. Then, set its 'mirror image'. Like this:
#1 is down, set #8
#2 is down, set #7
#3, #6
#4, #5
#5, #4
#6, #3
#7, #2
#8, #1
To make sure I don't miss anything I just pull the coil wire and just crank until the next valve in the numeric sequence goes down and just set them 1 through 8. This only works out so simply due to the firing order and mirror imaging of the ports.

How often you set them depends on how you drive the engine, among other things. From my experience a hard driven engine will recede the valves at a slightly faster rate, and you'll need to set them more often before the receded valve takes up all the slack and starts to hang open slightly - it will burn fairly rapidly. I set mine about every 5000 miles, but I rev mine pretty exuberantly.

Don't tighten those lock nuts too tightly or you will break the adjuster bolt - as I have done before. Snugly and firmly, but not tight.

1. Whenever the noise begins to bother you.

3. Tight enough that it won't come loose. (maybe about the tightness it was
when you broke it loose)
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

"Whenever the noise begins to bother you."

The worst thing is when the valves recede and tighten up. Then then valves get quiet. Too quiet. The head on my 544's engine is on its way out and I have to loosen the adjustments slightly bit by bit. A new head with hardened valve seats is in my future....

And be sure to recheck the clearance AFTER you tighten it, sometimes it spins the adjusting screw while you're tightening down the nut thereby blowing your careful adjustment. I really like JohnMC's method; it means you only have to turn the engine once over. I use a wrench on the main bolt down there under the fan (what's the name of that thing... argh!) as opposed to trying to turn it by hand with the pulleys and such which usually leaves wierd, greasy channels cut into your palms and makes the palm reader say, "You have a crappy car."
What does SHE know, anyway. Bitch.

-Ben
--
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And be sure to recheck the clearance AFTER you tighten it, sometimes it spins the adjusting screw while you're tightening down the nut thereby blowing your careful adjustment. I really like JohnMC's method; it means you only have to turn the engine once over. I use a wrench on the main bolt down there under the fan (what's the name of that thing... argh!) as opposed to trying to turn it by hand with the pulleys and such which usually leaves wierd, greasy channels cut into your palms and makes the palm reader say, "You have a crappy car."
What does SHE know, anyway.

-Ben
--
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