Bag of hammers

[swooshdave]

I set the tappet clearance at .22mm and started the 850T up. It sounded like a bag of hammers. Decided not to ride it like that.

I reset them to .005/.007in and they sound much better. You can still hear them work but they don't sound like they want to come through the valve covers.

I suppose talking about tappet clearance is probably only slightly less controversial than talking about oil.

[Matt Story]

Pretty certain you'll get a scolding for this.  Its supposed to be noisy.  A little loose is better than a little tight. I've always set mine to a tight .009".  It may sound noisy, and people who are not familiar with Guzzi will tell you its loud, but oh well.  Maybe look at the ends of your rockers at the valve.  Ive heard they can develop a pocket where the valve stem touches making it hard to properly lash.

[Tom]

"Loud valves save lives!"   

They will be noisy if set right.  They won't bother you as much if you wear earplugs. 

[lucian]

.22?  sounds more like a plug gap.

[Lannis]

The usual saying is "As dumb as a bag of hammers", since it's hard to move a bag of hammers around enough for them to be noisy; however, a bag of hammers IS very dense, and so is a good simile for stupidness.  (No comment on that relative to setting your valves too tight because of the noise!     )

The new standard for "Unwantedly Noisy", especially related to Moto Guzzis, is the Roperism

"As noisy as a washing machine full of Crescent wrenches."

Now THAT would be an unpleasant sound, assuming the washing machine could even turn under such a load .... Not only unpleasant, but deafening.   

Lannis

[swooshdave]

.22?  sounds more like a plug gap.

mm

[swooshdave]

The usual saying is "As dumb as a bag of hammers", since it's hard to move a bag of hammers around enough for them to be noisy; however, a bag of hammers IS very dense, and so is a good simile for stupidness.  (No comment on that relative to setting your valves too tight because of the noise!     )

The new standard for "Unwantedly Noisy", especially related to Moto Guzzis, is the Roperism

"As noisy as a washing machine full of Crescent wrenches."

Now THAT would be an unpleasant sound, assuming the washing machine could even turn under such a load .... Not only unpleasant, but deafening.   

Lannis

Hammers or crescent wrenches, either way it was too loud.

[pete roper]

The valvetrains, especially on the roundfins and even more so after forty odd years, do tend to be noisy. There are lots of contributors to the clanking from worn tappets, (Puting in oversized ones sometimes quiets 'em down, sometimes not.) to worn rocker spindles and bushes, worn rockers and indented valve stems. Probably a few other things too!

At the end of the day though it should be remembered that even if everything is as good as it possibly can be the original round fin motor was designed for police and military work. That meant not only was it designed to be worked on by spotty conscripts but it was also expected to sit for hours, idling, with a fat copper or squadie sitting on it in summer heat! The specified clearances are extraordinarily generous in terms of dealing with thermal expansion.

FWIW I ran all my roundfins at 5 & 7 thou, a tight 5 & 7 at that and never had a problem. Did it quieten them down? Yes, it did, to a degree. It doesn't explain though why my Convert is whisper quiet whether I set the clearance at 5 & 7 or 8 & 8!

Pete

[rodekyll]

I quieted down my 40-y-o Convert with the liberal application of a hydro engine.   

[swooshdave]

The other advantage of tightening up the clearances is the perceived horsepower increase. I'd guess conservatively it's up at least 20hp!

 

[oldbike54]

 I want what some of what Swooshdave is smoking 

 Dusty

[swooshdave]

I want what some of what Swooshdave is smoking 

 Dusty

Well, it's legal here! Come on over!   

[rodekyll]

I tried some of that Oregon pot.  It's almost the real thing, except for the taste and mine's better.  Oregon pot makes a Bag of Hammers sound like grammy-winning musical group. 

And I'm not saying if that's a good thing or a bad thing.   

[swooshdave]

Does anyone bench flow test Guzzi heads for fun? It would be interesting to see the flow numbers between the recommended clearance and acceptable tighter ones. Probably isn't significant as it's only about .005 in...

[oldbike54]

 You do understand that the only cooling period for an exhaust valve is when it is fully seated . What ever infinitesimal flow gains would be more than offset by increased exhaust valve temperatures , but go ahead , I'm sure that the 1 1/millionth of a HP gained by slightly more flow will be worth the burned exhaust valves .

 Dusty

[swooshdave]

You do understand that the only cooling period for an exhaust valve is when it is fully seated . What ever infinitesimal flow gains would be more than offset by increased exhaust valve temperatures , but go ahead , I'm sure that the 1 1/millionth of a HP gained by slightly more flow will be worth the burned exhaust valves .

 Dusty

Have you measured the clearances when it's hot? Does it actually close up? I'd assume with all alloy parts (head, barrel and I assume pushrods) they should expand uniformly.

At .007in on the exhaust I'm only .002 less that the book. I'm sure the valve will be able to take that.

But we'll see which dies first, the chrome bores or the valves! 

[oldbike54]

 I forgot , this is a test to destruction experiment ...

 Dusty

[bobdar]

Recent thread on valve clatter with some interesting ideas: 
http://wildguzzi.com/forum/index.php?topic=84761.msg1337140#msg1337140

What I found most interesting:  The OP (Jabberwocky) said that he set cold clearances at .006"IN/.008"EX at piston TDC's but measured .004/.006 hot and found by measuring at other positions (other than TDC's) that the hot clearances were as much as .011/.013.  Calvin 2007 suggested (Reply #9) that the proper position to measure clearance is not at TDC but at 180 camshaft degrees (360 crankshaft degrees) from maximum lift, which is the centerline of the base circle.  That's exactly how we measure clearances on our pushrod FF race motors.  Measuring at piston TDC really doesn't make a lot of sense:  the exhaust valve is going to start opening before piston BDC (less than 90 degrees of camshaft rotation).  May not make a lot of difference on a short-duration cam, but Calvin claimed it made his engine quieter.

[not-fishing]

Hey some of us like to Battle Rattle and a noisy valve train is just fine.  I don't want to do any valve work until after 100,000 miles, not before.

[swooshdave]

Recent thread on valve clatter with some interesting ideas: 
http://wildguzzi.com/forum/index.php?topic=84761.msg1337140#msg1337140

What I found most interesting:  The OP (Jabberwocky) said that he set cold clearances at .006"IN/.008"EX at piston TDC's but measured .004/.006 hot and found by measuring at other positions (other than TDC's) that the hot clearances were as much as .011/.013.  Calvin 2007 suggested (Reply #9) that the proper position to measure clearance is not at TDC but at 180 camshaft degrees (360 crankshaft degrees) from maximum lift, which is the centerline of the base circle.  That's exactly how we measure clearances on our pushrod FF race motors.  Measuring at piston TDC really doesn't make a lot of sense:  the exhaust valve is going to start opening before piston BDC (less than 90 degrees of camshaft rotation).  May not make a lot of difference on a short-duration cam, but Calvin claimed it made his engine quieter.

I seem to remember setting the adjustment on my MG (MANY years ago) by setting the intake valve when the exhaust was full open. I wonder if that would work here?

[oldbike54]

 I'm guessing you are being facetious ?

 Dusty

[bobdar]

No.  I think you are mis-remembering.  On an inline four cylinder motor you can adjust (for example) No. 1 exhaust lash when No. 4 exhaust is fully open or No. 2 intake when No.3 intake is fully open.  Doesn't work for a 90 degree twin.

[Penderic]

Meanwhile, back in the transmission .....


 

[swooshdave]

No.  I think you are mis-remembering.  On an inline four cylinder motor you can adjust (for example) No. 1 exhaust lash when No. 4 exhaust is fully open or No. 2 intake when No.3 intake is fully open.  Doesn't work for a 90 degree twin.

Oh, yes. Well that was about 30 years ago. Not surprised I got it wrong.

[trumps]

I had been running 6 and 8 since I rebuilt my motor 7000kms back, and it was rather rattly, even when well warmed up! Just last week I checked and adjusted them, they were still 6-8 as they were 3000kms ago when I checked last, but this time I set to 5-7, the reduction in valve train noise is quite noticeable! This week if I get a chance I will get her up to temp and check them hot just out of interest... Or maybe I won't, and will just keep getting up the poor thing LOL!

Craig

[Zoom Zoom]

Recent thread on valve clatter with some interesting ideas: 
http://wildguzzi.com/forum/index.php?topic=84761.msg1337140#msg1337140

What I found most interesting:  The OP (Jabberwocky) said that he set cold clearances at .006"IN/.008"EX at piston TDC's but measured .004/.006 hot and found by measuring at other positions (other than TDC's) that the hot clearances were as much as .011/.013.  Calvin 2007 suggested (Reply #9) that the proper position to measure clearance is not at TDC but at 180 camshaft degrees (360 crankshaft degrees) from maximum lift, which is the centerline of the base circle.  That's exactly how we measure clearances on our pushrod FF race motors.  Measuring at piston TDC really doesn't make a lot of sense:  the exhaust valve is going to start opening before piston BDC (less than 90 degrees of camshaft rotation).  May not make a lot of difference on a short-duration cam, but Calvin claimed it made his engine quieter.

TDC on the compression stroke. Bottom line is as long as you're not on the ramp of the cam, it should be ok to adjust the lash.

John Henry

[huub]

if  the bike has the original valve covers, and you want to quiten it , you can fit modern ( T3 etc) rocker covers.
the old model resonates.
the noise is not a real issue , just part of the joy of owning a old guzzi.

[John in PA]

I kinda like the "Song of the Valves" at about 4K RPM.  Reminds me that all's right with the Goose. 

A bit like running commercial tires on a dually pickup truck.  You get used to the "Highway Song of the Rubber"  too.

[TBShorty]

Tappet noise?  I've been riding my 3 cyl. Triumph Thunerbird Sport for 6 yrs. now.  The valve and cam chain clatter on it make the Guzzi sound kind of pleasant.  Just enough to let me know it's strumming along.  Those early Hinckley Triples were built with little consideration for quiet.  They make a glorious sound WOT though.

[swooshdave]

I had been running 6 and 8 since I rebuilt my motor 7000kms back, and it was rather rattly, even when well warmed up! Just last week I checked and adjusted them, they were still 6-8 as they were 3000kms ago when I checked last, but this time I set to 5-7, the reduction in valve train noise is quite noticeable! This week if I get a chance I will get her up to temp and check them hot just out of interest... Or maybe I won't, and will just keep getting up the poor thing LOL!

Craig

Let's see who's bike blows up first!