Please help me figure out why the valves on my T3 are sooooo noisy

[oldbike54]

 Mr Wocky , no snark intended , a couple of questions however .

 1. Were  the same shims used in reassembly as were already in place , not sure I understand how they could have grown in thickness .

 2. Don't understand the statement re shim thickness , are your measurements that of a free spring length , or of the total length including the shim ? I'm not understanding the measurements given , they seem to be reversed .

 Thanks

 Dusty

[twhitaker]

If I understand correctly the 37-38mm is the length of the spring in assembly at TDC. You add shims under the springs to get this dimension. This is a bitsa bike he made from several.

[oldbike54]

If I understand correctly the 37-38mm is the length of the spring in assembly at TDC. You add shims under the springs to get this dimension. This is a bitsa bike he made from several.

 Alright , are the valve springs in use new or used ? Just trying to gather information . Were the free lengths measured against spec ?

 Dusty 

[jabberwocky]

I measured the springs' free length, and they were fine. It's been a while ago, and my memory is fuzzy, but I recall the shims falling to the floor when I inverted the head, not realizing at the time that there were shims to watch after. I've never seen another engine with valve spring shims, so I wasn't expecting it. It makes sense to have them I guess, as it lets you compensate for dimensional changes after grinding valves and seats. Perhaps they were always wrong, and for some reason I got away with it before. But I do know that they were all too tight by at least 1mm, which might put them in jeopardy of binding at full cam lift. I'd like to understand it, but mostly right now I'm just happy that the engine isn't making a terrible clanking noise. I'll post up after I retorque, and reset the lash.

[acogoff]

     Think I would have a look at the cam followers after all that extra pressure/ pounding, just for giggles that is. And maybe give the pushrods the old roll to see if they are still straight test.

[Curtis Harper]

Good catch on the springs for sure, sounds like you have it nailed.  But here are three other things that are common in the valve train noise area that I didn't see discussed in the thread. If they were and I missed them, well I digress.  Two are human error, one is mechanical related.

The mechanical part is that more than once we have seen the ends of the pushrods get loose on the rods them selves and after you adjust them and then start the engine, the sit back in place and then the gap is obviously off. Replacement parts are needed.

The human error parts are easy to fix.
1: (and this happens more than you think) When reading the gauge, make sure you are reading the proper thickness. Most gauges now have metric and inch measurements on one side, but I have seen them where they are on opposing sides and sometimes folks don't catch that.

2: When checking the gap remember to push lightly downwards on the adjuster screw / pushrod to displace the oil in the lifter itself. The inside of the lifter is a cup, it holds oil and will add a few thousandths if not pushed out of the way.

[Triple Jim]

2: When checking the gap remember to push lightly downwards on the adjuster screw / pushrod to displace the oil in the lifter itself. The inside of the lifter is a cup, it holds oil and will add a few thousandths if not pushed out of the way.

Thanks for that, Curtis.  I'm about to adjust the valves on my Mille, and I wasn't aware of that.  When I'm done, it will be interesting to hear if the ticking is less than last time I adjusted them.

[redrider90]

Thanks for that, Curtis.  I'm about to adjust the valves on my Mille, and I wasn't aware of that.  When I'm done, it will be interesting to hear if the ticking is less than last time I adjusted them.

Dang I've been doing it wrong for a 1/4 of a century on my Mille and I am not be factious.
It's never to late to learn.

[Triple Jim]

Dang I've been doing it wrong for a 1/4 of a century on my Mille and I am not be factious.

That's fascist, Harvey... you're not being fascist.

[twhitaker]

LOL! Facetious.

[redrider90]

I'm taking my lumps here guys. 

[Dick]

So I checked them out, and every one of the valves had too much shim thickness. They were all around 35.5 and 36mm, when 37 to 38mm is where they should be.

Interesting and surprised no one has commented. My T manual, along with the LeMans factory hop-up kit supplement recommends 35.7mm-36mm installed spring height, not 37mm-38mm. Maybe my manuals have it wrong ??

[jabberwocky]

Hmmm. Weird, man.

[Triple Jim]

When checking the gap remember to push lightly downwards on the adjuster screw / pushrod to displace the oil in the lifter itself. The inside of the lifter is a cup, it holds oil and will add a few thousandths if not pushed out of the way.

OK, I did a valve adjustment yesterday, and followed your advice.  It's pretty clear that my valves are quieter than last time I did an adjustment, so I'm sure I was adding a little by not pushing on the adjustment ends of the rockers while measuring.

Again, thank you for that information.

[luthier]

Interesting solution.
The Ambo I'm building had a weird problem with the valves.
I had new valves , klined guides and they centre punched fairly heavily around the valve seats. I was a bit surprised actually.
Anyway I had one pushrod end that was cracked so I got another set from ebay.
When the set arrived I did the setup. But I found one pushrod needed to have minimal adjustment such that during rotation the rocker was coming in contact with the side of the top pushrod end.
I could see how this would cause the  pushrod head to crack and had a lot of thinking to do about how to cure the problem.
With a bit of help from my friends we came up with the best solution being to reduce the length on that pushrod which I did.
Thus the adjustment is now extended enough so the end rotates on the ball end without having the rocker arm interfering with the pushrod end.

Very strange, I can only think that the valve was set a little too far into the seat. If at the shop I would have had a small amount shaved off the top of the offending valve stem. But being in the sticks I think the pushrod solution was the easiest as long as it doesn't become loose. I doubt it will as the effort in thumping that end back on was as much as I would consider a pushrod shaft would take without bending.

I'm expecting clearance changes as it hammers itself further on, and this will be a case in point of making sure you return the same rod to the same hole should you have those heads off again.
Anyone else had this ?

[Orange Guzzi]

I had a problem like this once.  Worked on it for weeks.  One day at a gas station, a guy walked up to me and said "nice bike, you have a small end rod bearing that is worn out and letting the piston slap in the cylinder".  He was exactly right.  Pulled the rod, bought new bearings, gave all the parts to the father in law who worked on rods everyday.  2 day later, the bike was quite. 

[normzone]

Good catch on the springs for sure, sounds like you have it nailed.  But here are three other things that are common in the valve train noise area that I didn't see discussed in the thread. If they were and I missed them, well I digress.  Two are human error, one is mechanical related.

The mechanical part is that more than once we have seen the ends of the pushrods get loose on the rods them selves and after you adjust them and then start the engine, the sit back in place and then the gap is obviously off. Replacement parts are needed.

The human error parts are easy to fix.
1: (and this happens more than you think) When reading the gauge, make sure you are reading the proper thickness. Most gauges now have metric and inch measurements on one side, but I have seen them where they are on opposing sides and sometimes folks don't catch that.

2: When checking the gap remember to push lightly downwards on the adjuster screw / pushrod to displace the oil in the lifter itself. The inside of the lifter is a cup, it holds oil and will add a few thousandths if not pushed out of the way.

Thank you very much for that, Curtis - 1) I'm aware of, but always good to be reminded. The mechanical and 2) I will look at next time I'm in there.

I love this place 

[Muzz]

Don't know what the Guzzi set up is like, but on an old beater BMC A series motor I was using the valve stem was quite a bit smaller that the slightly curved rocker face. Over a period of time the valve stem had punched/worn an indent in to the rocker; not visible when the engine was assembled. The flat face of the feeler gauge read the high spot, so effectively the clearances were too large. Finally removed and disassembled the rocker shaft, and as it was just an old beater carefully reground the face to remove the high spots. Some of these were quite large. Just used an aluminium oxide wheel on my grinder so it wouldn't burn the metal. Motor ended up beautifully quiet, and still ran beautifully until it was sold.