Tuesday, October 18, 2011

Valve adjusting

Not much car activity this summer due to a torn Achilles, but I did get the valves adjusted on the coupe this week. If you've never done it before – and I've always avoided the job – it's actually pretty easy.

1st, ignore the manual's advice to do it with the [warm] engine running. You'll likely burn your arm off on the exhaust manifold! I do it with the engine cold and give the adjustment one extra thousandth.

Here's how I did it.
• Remove the fender piece that gives you access to cyl. 1-3.
• Remove the fuel line from to the carb, the air tube to the heat riser and the gas pedal linkage. I also had to remove a plug from the back of my fuel pump to get enough clearance.
• Remove the bolts holding the valve covers on, incl. the breather tube, and the valve covers themselves. Bingo, there are the valves, which look like this.

From Pontiac Pictures

You will need two 9/16" open end wrenches, one skinny one (you may have to grind down on of your wrenches for this job), and a feeler gauge. The book says they should be adjusted to .009" "go" to .011" "no go", meaning a .011 feeler gauge shouldn't fit between the gap (9 or 10 would). It also says leave them a little loose for high speed driving. Chilton's says give the gap an extra .001" when adjust them cold, so I was shooting for .011 "go" .012 "no go."

Take out the plugs (blow air in the plug head holes first), then take off the distributor cap. Turn the engine until you are top dead center on cyl. #1 (when the points are wide open and the rotor is pointing to that position), then that cylinder is ready for adjusting. Work right through the firing order to get them all.

Place the skinny wrench on the lifter head, then the lock nut just above it is loosened (carefully so you don't skin your knuckles) with the other wrench. The top nut, also 9/16", is then turned to the right to narrow the gap, to the left to widen it.

The feeler gauge fits between the bottom of the valve and that upper nut. I found that hand adjusting the nut with the feeler gauge in place let's you get a better fit. Not so easy on #3 & 4 cylinders though.

Once they are all done and double checked, button it back up and you're good to go.


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