Rocker shaft to rocker arm clearance, Is there a spec? |
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Rocker shaft to rocker arm clearance, Is there a spec? |
Woody |
Jul 30 2013, 07:37 AM
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#1
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Sandbox Rabblerouser and head toilet scrubber Group: Members Posts: 3,858 Joined: 28-December 10 From: San Antonio Texas Member No.: 12,530 Region Association: Southwest Region |
This is on a /4 2056. I've been chasing a noise that I believe is coming from the top end. It only occurs at idle and will completely disappear right off idle. It sounds like really loud valve clatter. Valves were recently adjusted and were not too far out of spec, Maybe a little bit tight. Noise was present before the valve adjust. On startup it is pretty bad, as the oil heats up it gets worse, but when the engine is at full operating temp after a 30 minute drive the noise is gone. I pulled the rockers and shafts to inspect for wear. The rocker shafts show some wear visually and measure at or just below spec at 19.94mm or .785". Haynes shows the spec at 19.95-19.97 mm. The shafts are not ovaled. The rocker arms measure out at 20.02 inside diameter or .788" and also are not ovaled. Does anyone know what the clearance is supposed to be?
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r_towle |
Jul 31 2013, 05:47 PM
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#2
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Custom Member Group: Members Posts: 24,591 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
I think of it like this.
You never really know what the rocker is going to do with springs. You reduce that variable quite a bit when you use solid spacers... Then you are getting exactly what you expect from the whole valve train. Otherwise, with the rocker having the ability to move...you may not get the lift expected on each cylinder and that could make things run less than optimal. For what, 4 bucks each...why not. The rest of the parts you can get fairly cheap also.. New shafts, 16 bucks....just do that...no hesitation in my mind. Rich |
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