9n valves

Posted in the N forum, no answers...... Try it here. Working on a ford 9n for our preacher. Various issues led us to take head, manifold and valve cover off. When hand cranking the engine the valves make a funny snap/clank noise. They had a lot of carbon build up. Took them all out and cleaned everything really good. Put it back together and still clanking. Tractor was running, poorly. And didn't hear the noise.....
<video src=https://www.yesterdaystractors.com/cvvideos/cvvideo87491.mp4 controls>http://forums.yesterdaystractors.com/cvvideos/cvvideo87491.mp4</video>

Dry they will do that during the rotator process. With covers and oil on it all they would be quiet probably.

Whats the compression?
Put a vacuum gage on it see where it is ? Steady neeedle 18 to 22 is normal if not then you got other issues.
Check each plug firing .
Old gas ?
Not enough gas , filter
Use vacuum gage to adjust carburetor to improve vacuum to steady needle 18 to 22
Run some mystery oil thru it get those valves moving good.
Thats all I can think of , need another cup of tea , to early

Possibility #1)
The valves are binding in your guides. When the pressure generated by the camshaft lobe on the lifter is greater than the grip of the interference fit between the guide and the valve stem, the lifter's force overcomes the friction of the valve and guide molecular bond and you hear a CLICK or SNAP as the two pieces quickly separate.

Possibility #2)
Your guides are loose in the block from wear due to ill-fitted (or fitting) keepers or overzealous prep.. Just how much cleaning did you do to that casting? A quick pass with a brake hone through the guide and lifter bores never hurt anyone, but prolonged grinding here can give you an oversized hole that will allow a lifter or guide room enough to move ever-so-slightly from side-to-side when being articulated, to the point of generating some mechanical clatter.

Possibility #3)
You are being overly cautious. What you are hearing are the normal sounds of a collection of metal parts working in concert, but you are hearing them at 1/5000th speed, without the benefit of cushioning oil spray, metal covers, liquid-filled chambers along with other, competing noises (fan noise, exhaust flow, gearbox and rear axle whine) to dampen or distract from the sound. Add to that the sneaking suspicion that if you screw up the preachers tractor, you can almost bet it will be the subject of a sermon at your expense. No doubt you can imagine that by his accounting, the trials and tribulations of Job will pale in comparison to the suffering his poor Ford had to endure in your hands if this rebuild goes awry. Hey, youre doing the best you can with probably half the congregation looking over your shoulder second guessing your every move and I'm sure the pay isnt that great, so what is he expecting, some kind of miracle?

Possibility #4)
New hearing aids. If you wear them, take them out. See the difference? That problematic engine now sounds like finely tuned Maserati! When I take mine out my wife's voice goes from Fran Drescher to a slightly muffled Kathleen Turner. Much better. Plus, with them out, if anyone complains about how noisy the valvetrain is on that freshly rebuilt Ford, you'll never hear it OR them!

Possibility #5
Beats me. Put it together and hope for the best. As any mechanic will tell you about any mechanical issue on any type of vehicle when his best efforts are all for naught; They ALL do that!

Warbaby, most entertaining post in a while! Not sure about #1. #2 we cleaned the carbon off and out of everything with carb cleaner and really fine wet/dry sandpaper. Guides are pretty tight in there. #3. Luckily the preacher is pretty easy going and knows he only gave $500 for the tractor, heck rear tires are almost worth that! I've been called out in sermons a couple times, I don't mind! Lucky he just wants it to run and bush hog hunting club a couple times a year. Lol #4. No hearing aids...... #5. Last night at church preacher said put it back together and hope for the best. Me and another guy were discussing it and he said I'm over thinking it. Parts are dry and moving really slow, that's why we hear the noise. Head gasket will be here tomorrow. Will put it together and hope for the best..... Update on Friday evening.

could it be that the top of the lifter has a depression worn in it and when you set valve clearance you cant notice that but it will make the real clearance too big hence the valve clatter??