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

[jabberwocky]

I could make this a very long story, but will try to pare it down. On a cold start, the engine sounds great, mostly just the exhaust sound, and the whir of the timing chain. AFter about five minutes of running the valve start getting clicky, but not bad. Then after a few more minutes they start to get LOUD, like loud enough that when I pull the valve covers off, I expect to see marks showing that the rockers are hitting the covers , but they don't look to be. I have the valve clearances set to .006 intake, and .008" with the engine cold. Last night I retorqued the head bolts and reset them to the above figures. So today I ran it, just let it idle for 5-7 minutes and just listened to it at a slightly elevated idle to see how the noise progressed. Once it got noisy after 5 min or so , I quickly pulled off a valve cover and measured the clearances with the engine hot and noisy. I expected the clearances to increase, based on the noise, but it had actually tightened a little, .004 int.006 exhaust. Just for fun, I took clearances with the crank in other positions, and noted that the exhaust clearance got as wide as .013, and the intake.011. both cylinders did this. I don't know if that is normal or not, but I assumed that The clearance would be at it's greatest with he piston at TDC compression stroke. Last night while re-torquing, I actually measured each rocker shaft for wear, and found none, and the rockers seem to ride on the shaft without any slop. I realize that this bike will exhibit valve noise when everything is as it should be, but this is just off the charts. I hope someone here can shed some light on this. Thanks.

[Triple Jim]

Are you sure it's the valves that are making the noise?  Is the noise on the left and right cylinders equally?

[oldbike54]

 Setting the valves on the wrong stroke maybe ?

 Dusty

[RinkRat II]

 Yeah Buddy, doesn't sound like your on TDC Compression stroke.  Those clearances shouldn't increase that much. My .02$

      Paul B

[jabberwocky]

No, I definitely didn't do that. In the final push to get it all together, I DID manage to set the ignition timing 180 degrees out, which caused a delightful fireball out the mufflers. I am 99% certain that it is valve train noise, it seems roughly the same both sides. Maybe tomorrow, I'll improvise a stethoscope.

[jabberwocky]

IIRC, if you went to set clearances at TDC there wouldn't be any clearance at all, beast the valves would be  in overlap. You guys will have to trust me that each cylinder was at its TDC on the compression stroke when the clearances were set.

[oldbike54]

IIRC, if you went to set clearances at TDC there wouldn't be any clearance at all, beast the valves would be  in overlap. You guys will have to trust me that each cylinder was at its TDC on the compression stroke when the clearances were set.

 Not sure I understand the no clearance at TDC comment . Humor us and double check your methodology .

 Dusty

[Triple Jim]

I assume he meant the wrong TDC, when the valves are in overlap.

[oldbike54]

I assume he meant the wrong TDC, when the valves are in overlap.

 That's what I'm thinking .

 Dusty

[CalVin2007]

  I've seen this before...and my CalVin exhibits a bit of it too. Actually the most clearance should be not right at TDC but 180 camshaft degrees from maximum tappet lift on each valve.That's where the base circle center is. Finding peak lift then turning the crankshaft one full turn will put the cam where it needs to be for each valve adjustment. It's picking fly specks out of the pepper I know...but that's the deal. I adjust my CalVin valves at the point of greatest lash...and it's much quieter. And something else....sometimes cams are sloppily ground and the base circle isn't true. Then you just have to find a happy medium for adjustment. Too tight and you risk a burned valve, so caution should be exercised.

  Terry

[pete roper]

Too long bolts in the rocker spindles? Worn bores for the tappets?

Pete

[Two Checks]

That's what I was about to post worn rocker shafts/bushings and clogged rocker shaft oil passages from timing chain tensioner bits.

[atavar]

OK, my guesses, rod bearings or cracked exhaust.  Does the noise get better or worse above 2KRPM?

[jabberwocky]

I assume he meant the wrong TDC, when the valves are in overlap.

Yes, that is what I meant, thanks for the benefit of the doubt.

[atavar]

I have had exhaust leaks from thin cracks that sounded EXACTLY like tappets and got worse as it warmed and the crack opened. 

[unclepete]

Guzziology mentions the possibility of a groove the width of the valve stem being worn into the rocker arm surface , so the feeler gage bridges the worn area and measures from unworn area of rocker arm to valve stem , allowing a wider gap than intended . I have no personal experience with this , but it seems possible .
Also , my info indicates .009" clearance both in and exhaust for the T-3 . That's what it was when I got it , so I did not question it . Is that wrong ?

[Triple Jim]

Finding peak lift then turning the crankshaft one full turn will put the cam where it needs to be for each valve adjustment.

Maybe not.  I'd think that ideally you'd measure clearance at the tightest place in the base circle, since that's the spot you're trying to keep from accidentally opening the valve at the wrong time.  Barring that, which I usually do, I follow the manual's instructions for the particular engine.  No disrespect meant, I'm just trying to think of what might be happening here.

[fotoguzzi]

Guzziology mentions the possibility of a groove the width of the valve stem being worn into the rocker arm surface , so the feeler gage bridges the worn area and measures from unworn area of rocker arm to valve stem , allowing a wider gap than intended . I have no personal experience with this , but it seems possible .
Also , my info indicates .009" clearance both in and exhaust for the T-3 . That's what it was when I got it , so I did not question it . Is that wrong ?

what he said, how many miles on this motor?

[chuck peterson]

Grade of oil? Old t3 beast like that probably a 20-50

[jabberwocky]

So heres the history of this engine in the time I've had it.

The bike was a basket case when I got it, and I went through everything. Thankfully I had several engines to cannibalize.
I got some near new iron sleeved cylinders with matching Venolia 89mm high compression pistons. I built the engine with a like new crank, new rod bearings, I had a local machine shop grind the valves and k-line the valve guides. Out of what I had on hand I came up with a good unpitted cam, smooth lifters, unworn rocker shafts, rockers with smooth contact faces and tight bushings. New timing chain, used gears. Knowing that the pistons were high domed, and pinging would be a likely problem, I used two base gaskets on each side(this is an important detail in the story). The bike ran great, no bad mechanical noises, but it did ping. I backed off the timing, but then it was hard to start, so I put it back to stock timing, and used octane booster, which worked but was annoying. I put about 5000 miles on it in that first season, and like I said it ran great, only complaint was the pinging.


That winter, I took the top end off and sent the pistons to a machine shop to have the crowns milled down to match the height of Guzzi 88mm  pistons. I also got custom copper gaskets made, stock thickness, which were 89mm bore, as the stock Guzzi 88 mm gasket hung into the bore previously, which didn't seem like a good thing. When I put it back together, this time I only used 1 base gasket o each side, because the CR would now be lower. All back together and running, it ran well again, and no pinging. A few weeks into the riding season, I started noticing the engine making a hollow knocking sound in the bottom end when I pulled the clutch in, and the later it started doing it on overrun. The rest of the season I looked into the cause of that sound, and in the process, pulled all sorts of things apart, never finding anything wrong. It was very frustrating, and to make matters worse, the valves started seeming noisy. Seemed like two different problems, but maybe related. Maybe rode the bike 2000 miles that summer. Pulled it apart in the fall, determined to find the problem.

I found that the notches in the cylinder skirts has some marking where the rod bolts had been hitting them, just barely. It didn't do any real damage, so I just clearances the notches just a bit more with a die grinder and files, and then re-honed them, and checked to see that there was adequate clearance. It seems that having two gaskets in there raised the skirts just enough that the rod bolts never hit the sleeves/skirts, but when I went to one gasket, it started making noise. While the engine was apart, I examined the rod bearings, lifters, cam, rocker shafts, rocker faces and bushings, push rods. Gave the valves a light lapping, and put it all together. I started it for the first time about a week ago.

The bottom end knock is gone, because I clearances the notches in the skirts. It runs beautifully, great power, no smoke, no unusual vibration, but lots of tink-tink-tink after warming up for a few minutes. So last night, I tightened up valve clearances a little, just to see what it would do, knowing that it isn't a good long term solution. I also doubled up valve cover gaskets, because although there are no telltale marks, it really sounds like the rockers are hitting the valve covers. So I started it up again cold this morning, and again it sounds great. Idled for about five minutes with occasional throttle blipping, and it stayed quiet longer than I bought it would, then  suddenly the loud tapping started again. I thought it was interesting that it started so suddenly. I do indeed have the proper rocker shaft securing bolts, and I have confirmed that oil is going where it should. I may soon just swap out push rods and rockers and shafts with others that I have, just to see what happens. Oy Vay!

[bobdar]

I'd try Calvin2007's procedure to find CL of the base circle, makes perfect sense to set the lash at that position.  TDC is not going to give you CL of the base circle.  You mentioned that you first noticed the lower end noise when pulling the clutch in, and I'm wondering if there is excessive end float on the crank.  Make sure you have clutch free play, then put a dial indicator on the crank nose and move the crank back and forth from the flywheel.  Not sure what the spec is, but .005" to .010" would be typical.

[jrt]

I may soon just swap out push rods and rockers and shafts with others that I have, just to see what happens. Oy Vay!

Are you using matched cam followers, rockers and pushrods?  The radius on the ball ends changed around the time from loop frame to Tonti frame.  Not exactly sure when, but if I recall, you can't mix early and late parts. 

[sbaker]

Loud valves save lives...

[Dick]

Cam end float ?? Rod small end bushing ?? Loose pushrod end ?? Loose valve guide ?? I believe the pushrod ends, rocker adjusters, and lifters all updated with the T3. Did you happen to check the squish during top end overhaul??Good luck.

[mar54]

have you checked that the valves do not touch the pistons?

[jabberwocky]

^funny you should mention that, as this afternoon's messing about with it led me to pondering that. I'm going to borrow a friends borescope and check out the piston crowns for marking. Thanks for the suggestion.

[jabberwocky]

Well, I had started to think that I had a situation where the valves were kissing the pistons, so I pulled a head off. I was sure there would be some marking, but nope, not even the slightest blemish. Hmm, now what? I had recently read something about the shimming of the valve springs, and I remembered that I hadn't really understood what was going on there when I last put the heads together, I had just put them back together the way I had thought they came apart. 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. It doesn't make the noise anymore. I guess the springs were binding, but only when the engine was fully warmed up. I'm a little skeptical still, but I rode it for an hour today, and it never got noisy. Whew! I have had the valve covers on and off at least a dozen times in the last couple of weeks trying to figure this out. Boy what a nice machine a Guzzi is. The handling is such a joy compared to my /5 which I've been riding exclusively while sorting this mess out.

[chuck peterson]

Your the Weiner! No one guessed that...good fix

[Groover]

Are the shims you mention located between the spring and the spring retainer?

[jabberwocky]

No, they're between the spring(s) and the cylinder head casting. I'm afraid to declare victory until I've retorqued and adjusted the valves again, but last nights ride gave me warm fuzzies.