valve train noise
 

Hi Barners
Here's a question I'm puzzeling over. My 30 A Fordor restoration is just about finished with the running chassis. I have a rebuilt engine that seems to run fine now with about two or three total hours of light operation. I'm trying to track down a light to medium tapping noise at valve train speed that has eluded identification. It is not a loose valve clearance . I've checked and reset the tappet clearances three times. They are OK. I can not tell where the noise is coming from with the "Stick to ear" method. but it seems to be from the right side top area in general. I'm not sure whether to move on (and depend on the writer's opinion that these noises either go away by themselves or get worse enough that you can identify them), or to keep at it and fix the problem while everything is exposed and accessible.
What else causes clicky tapping sounds at valve speed? The noise is present in all engine speeds and spark advance settings I've tried. The engine has a reground cam. Can the valve guides create noise by being too loose or even too tight? Aside from checking valve springs and guides, is there anything else that might help diagnose this problem? Thanks to all the barners writing on this topic!
Merry Christmas, Rancho Deluxe

Re: valve train noise
 

I would check the water pump first. Check to see how much end play is in the shaft. Also, I had one engine that had a similar noise when I had gotten it. The person that I had gotten the engine from had forgotten to re-install the spring in the camshaft plunger, which was also worn and should have been replaced.

Re: valve train noise
 

distributor? Maybe the shaft going to the oil pump drive gear?

Re: valve train noise
 

Distributor shaft is a two piece to allow for movement. If you have a one piece that might be the noise.

How much play is in the center cam bearing?

Re: valve train noise
 

Remove the fan belt and see if anything chances. This will rule out water pump, generator etc.

If no change, I would then consider first loose crank pulley or bolt. (I am sure you have already checked this).

Then I would look at the timing gear (loose) or the plunger or spring that pre-loads the cam shaft.

These things are not too difficult to check and definately can cause the kind of noise you describe.

That is where I would start.

Chris

Re: valve train noise
 

OK, I'll try to give my 2 cents worth and it is probably not worth that. These motors are so old and have been used for everything from car motors to boat anchors that there is wear in places most engines don't have places. My theory about valve train noise when the clearances are correct and there is still a clatter is loose valve clearances. Now, I know I just said the valves were adjusted correctly but, if you have wear in the cam at the middle bearing and wear in the block at the middle cam bearing you have deflection of the cam. This causes the valve next to the working valve to have an increased clearance and will cause a tap. The only way to fix this is to install new cam bearings and a new cam with correctly ground cam bearings or bore out he bearing bores and get a new cam from Bill Stipe with oversize bearings. The best way to try to avoid this situation is to measure the bores and cam bearings and try to get a block with as little wear as possible and a cam that is likewise.

Like I said, 2 cents worth and likely not worth that.

Re: valve train noise
 

Have you shorted out the cylinders to see if that makes any difference to the sound?