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post #1 of (permalink) Old 09-17-2003, 06:41 PM
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valve confusion

I'm having weird problems. So I have a new cam (summit racing cam). Also, new lifters, rods and the heads are remanufactured with new parts. So why am I having problems [img]images/graemlins/crybaby.gif[/img]. Because on the drivers side it sounds like there is a loose valve and I can't stop the ticking. I'm trying adjust the valves while the engine is running because I should it would be easier to pin point the lose valve, but that's not working. When the engine is idling the ticking doesn't sound so bad. When I rev the engine and then let go the ticking sounds the worst. Does this sould like a bad lifter? On the passangers side I had to change a lifter a while back to get the ticking to go away. Does Summit sell questionable parts?
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post #2 of (permalink) Old 09-22-2003, 12:01 AM
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Re: valve confusion

The most common cause for SBC valve thicking noise is the adjustment for the lifter pre-load. There are several ways to get the lifter pre-load, I doubt my way is any better or worse than any other way of adjusting.

I adjust the rocker arms one cylinder at a time with the engine off, all the spark plugs removed so I can rotate the engine with a socket wrench on the harmonic balancer bolt. When I make lifter adjustments, I make sure each and every cylinder I'm adjusting the rocker arms on is at Top Dead Center of the compression storke. I turn the adjusting nut of the rocker arm until the push rod has no free play to go up or down on the lifter or rocker arm. I then turn the adjusting nut of the rocker arm 3/4 of a turn more. The lifter pre-load for a SBC is .040". By turning the rocker arm adjusting nut 3/4 of a turn, once the zero up/down free play is set, the push rod will be pushed into the lifter .040".

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post #3 of (permalink) Old 09-23-2003, 04:49 PM
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Re: valve confusion

That ticking sound may be an exhaust leak around the head and manifold, especially since it increases with RPM. Try using a stethoscope to pin point the problem (they can be found at secondhand stores everywhere) If you don't have one you can use a 3/4 to 1 inch hose. Put one end to your ear and move the other end along the valve cover and exhaust to listen for the noise.
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post #4 of (permalink) Old 09-23-2003, 06:38 PM
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Re: valve confusion

I have nothing to contribute to the problem in this post and I know very little about the actual mechanics of engine building, repair, and tuning, but I'd just like to say thanks to dave for fielding a lot of the engine questions in a rally dead forum.
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