scott12180

Why One Noisy Valve?

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I have a 1932 Packard Standard Eight.

I've set the valves several times to everything from slightly loose (0.006 each) to factory specs of 0.004 each.  And I always have one noisy valve.  *Tick* tick *tick *tick*. . . . In an otherwise quiet engine it is annoying.

 

I think I've located the valve --- number two exhaust. But why is it noisy?  When I rebuilt the engine, the valves were all new from Egge, seats ground. 

 

Any suggestions for quieting this one out of 15 other well behaved valves ... without closing it up too much?

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Getting a quiet valve train when rebuilding a worn engine involves much more than just replacing valves.  As you know, the valve is not the only part of the valve train that can make noise that gets transmitted to where the valve is exposed.  So, because the noise is heard at the valve it's assumed the valve is the problem.

 

Some of the things that can cause valve noise.

1. Rocker arms  and adjusters that have uneven wear and need to be re-ground.

2. Wrong rocker arm geometry.

3. Worn or rebuilt rocker arm shafts and bushings that are not square to direction of movement.

4. Valve guides that are worn, or not cleaned of carbon/burned oil.

5. Guides that are hour-glassed too tight from improper press fit size, or wrong type of guide material.  

6. Uneven tappet, pushrod wear that was not re-ground square at the time of the rebuild.

7. Pushrods not perfectly straight.

8. Worn pushrod guides.

9. Wrong valve spring tension.  

10. Valve springs that don't sit straight.

 

It's a long list that can cause "valve noise". And very often it's not even the valve that's the cause of the  noise. 

 

Paul

Edited by PFitz (see edit history)

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Try rotating the suspected tappet around the full 360 in it's bore while measuring every 45 degrees or so. You may find the base of the tappet or the tip of the valve is not worn evenly and the clearance varies. You might be able to find a suitable compromise adjustment or not.

Edited by misterc9 (see edit history)

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I assume this is a flathead engine with some sort of adjustable follower between the cam and the tip of the valve. I assume you are sticking the feeler gauge in right at the tip of the valve. Is that pretty much right?

 

I would figure out how to get a dial indicator on the follower, probably with a magnetic base and an offset foot kit. Do it however you can. Straight on is best, but if you can't, you can't. Get hold of the follower with something and move it up and down. Try turning the follower as suggested my misterc9,

 

Compare what you find to a known good exhaust valve. If there had to be angle on the dial indicator, make sure it is the same.

 

All will soon be clear. If it isn't actually loose, it must be something else (guide or whatever). Lots of good possibilities in this thread so far.

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On 11/24/2017 at 9:07 AM, Owen_Dyneto said:

Worn cam follower roller or associated pin.

Can the cam followers be removed and more importantly replaced without removing or disturbing the associated valves?  

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Yes they can.  If the cylinder head is off you can make the job easier by blocking those valves that are open with wooden wedges so they stay open when the rocker/lever roller assembly is removed. But even with the cylinder head on the rocker lever/roller assemblies can be removed and replaced.

 

Curious why you didn't post your question in the Packard section of this forum.

Edited by Owen_Dyneto (see edit history)

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11 hours ago, Owen_Dyneto said:

 

Curious why you didn't post your question in the Packard section of this forum.

You get more visibility and better Response in the general technical section. I also thought this problem may be relevant to similar L-head engines.

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There's an additional possibility on a Packard. Each roller rides on its own riveted shaft that over time can work loose. I am uncertain of how to repair this, but know someone who might be able to advise you if this is the case on your car.  

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