Rocker Clatter No More

[Guzler]

Using TDC compression method left my rocker too loud. Actually had more clearance a little off TDC.
Sloppy chain? Dunno.
So I pulled the starter, rotated crank to intake 2 full open and chalked the crank through the starter hole.
Rotated crank 1 revolution to mark. This has the cam as close to base circle as possible. Repeat 3 times.
Runs fine and sounds like a sewing machine. No, really - a sewing machine. 

[Huzo]

It’ll sound like a single cylinder sewing machine if you burn a valve...

[oldbike54]

 Somehow I don't think this will end well .

 Sounds like you have effectively reduced the tappet clearance to near zero , why do you think this is a good idea ?

 Dusty

[Huzo]

Somehow I don't think this will end well .

 Sounds like you have effectively reduced the tappet clearance to near zero , why do you think this is a good idea ?

 Dusty

Because he hasn’t run it long enough to blow it up....

[acogoff]

     A long lived Guzzi clatters. Just saying.

[John A]

What bike? 
Edit, a couple more questions
Will it run when it’s hot?
Steel or aluminum pushrods?
Are you going to do the valve job or take it somewhere?

[Markcarovilli]

I’m with Dusty on this. 

You may want to rethink it....

Mark

[oldbike54]

I’m with Dusty on this. 

You may want to rethink it....

Mark

 Here is a fact , all of those engineers , and the thousands of mechanics who maintained Guzzis and airheads recommend running a certain clearance , a properly adjusted solid lifter design will chatter , if it isn't chattering something is wrong .

 Dusty

[CalVin2007]

 If he's setting each valve to point of max lift,marking the flywheel,then turning the flywheel one full 360* revolution and then setting the lash then it's a great way to do it. The cam will be 180* from the "point" of the lobe and will be on the absolute base circle.
   I've been doing mine that way for a long time...and on many other engines as well. 

  Terry
   

[mechanicsavant]

I don’t know about Guzzi cams . But as a Renault Tech the factory said to not deviate from the TDC method as the heel wasn’t precision ground they only got fussy in the ramp area’s. Just saying

[wirespokes]

The 84 LM III I recently got must have been set that way. When I checked the valves at TDC the intakes were about .0015 and exhausts were .003". It had been running hot and idled much better once set standardly.

Thankfully I don't think it had been run very long with those settings.

Yes, the valves will make less noise with less clearance, but they also won't rest on their seats as long. Since the valves cool down by transferring their heat to the seats, they'll run hotter. Not a good idea on an air cooled engine.

[Guzler]

What bike? 
Edit, a couple more questions
Will it run when it’s hot?
Steel or aluminum pushrods?
Are you going to do the valve job or take it somewhere?

77 T3, all stock, quite a few miles
Just got back from stoplight racing for an hour an a half
Intake and exhaust at .009 go, .010 no go.
Carbs balanced.
Starts, runs, stops. No misfire, no backfire.
Alternator is good, points look new.
Been wrenching 40 years, just can't stand a valve train beating itself to death.

[moto-uno]

 That certainly doesn't sound like overly tight clearances , within a thou or so isn't going to be reason for concern .
I've got a couple of Le Mans 2 cams kicking about , so maybe I'll check the base circles with a dial indicator and see how many
degrees it remains unchanged at .  Peter

[80CX100]

I've always set clearances at TDC, if there's a standard baseline, why aim for something else?

I've read many times that it doesn't have to be set exactly at tdc as long as the valves are both loose, you're close enough;idk?

I'm having a hard time wrapping my head around your technique and the concept, but irregardless, isn't there a saying "noisy valves are happy valves" ?
 
fwiw

Kelly
 

[Huzo]

Irregardless...? 

[oldbike54]

Irregardless...? 

 Awkward but acceptable , sorry .

 Dusty

[Huzo]

Awkward but acceptable , sorry .

 Dusty

Well if it’s unwrong, then I’m not unaccepting of it...

[oldbike54]

Well if it’s not unwrong, then I’m not disaccepting of it...

 Look mate , Okies and Ozzies should probably not be language police , fair enough ?

 Eye gno yu agrie , rite ?

 Duhstee

[Huzo]

Know eye do knot Dustie, butt eye’ll deferr two yaw quite reasonable request and resolve to cease and desist in this line of digital discourse..

[80CX100]

Irregardless...? 

     I can see the redundancy of the double negative now that you point it out, I'm sure there's a fancy grammatical term for it.

     Grammar and vocabulary were never one of my strong suits, old age has seemingly left what little I possessed in tatters,lol.

     Please feel free to keep holding me up to the standard you've established, you've set the bar high, I'll do what I can to aim above it. 

     Carry on mate

     

[Guzler]

I've always set clearances at TDC, if there's a standard baseline, why aim for something else?

I've read many times that it doesn't have to be set exactly at tdc as long as the valves are both loose, you're close enough;idk?

I'm having a hard time wrapping my head around your technique and the concept, but irregardless, isn't there a saying "noisy valves are happy valves" ?
 
fwiw

Kelly

Sure, TDC let's you adjust both rockers at once. To save time I guess.
Like I said TDC compression does not give max lash on this OLD farm tractor. I can hardly see any markings on the flywheel. Left cyl. ignition timing is different from the right as is carburetor adjustment. I think Mandello was hammering out as many T-3s as possible for the quick money.
Anyway, mine is my only transportation. Ridden to the church, doctor, and grocery store. Other wise in shelter and never sees rain.
Present dress is gloss black paint, black velvet seat, and fishnet stockings.

[Huzo]

    I'm sure there's a fancy grammatical term for it.

There is a term for it and it’s far from fancy...
Carry on, all in fun...
But I digress..(as usual)
I thought my Norge was getting rattley  in the valve train and was opening my wallet for a new set of guides, spindles and anything else that a near 200,000 k bike would need.
I did the mod required to fit a better cam chain tensioner in and it’s as quiet now as a VFR 800 Honda at idle.

https://youtu.be/C3wsYLPEoYA

I had taken the clearances hazardously close to try to get rid of where I thought the slappiness was originating, only to find it made little or no difference.
Now I run 4 and 6 thou’ and she’s as sound as a nut....

[Tkelly]

Nice T3!

[bodine99]

 :huh:Oh boy not goodski

[John Croucher]

I had an SP engine that had more clearance past tdc on all 4 valves.  Checking the piston position at tdc with a dial indicator an timing mark matched, cam did not.  I adjusted the clearance based on the cam position. Not the timing mark. 

On a hydro/PI engine, the adjustment is 1-1/2 turns past contact with push rod.  The three PI engines I have taken apart all had worn rockers and valve stem ends.  I attribute this to low oil flow caused by oil loss around the tappets.   A PI engine should have the valves adjusted also. I would suggest every 20,000 miles.

[John A]

77 T3, all stock, quite a few miles
Just got back from stoplight racing for an hour an a half
Intake and exhaust at .009 go, .010 no go.
Carbs balanced.
Starts, runs, stops. No misfire, no backfire.
Alternator is good, points look new.
Been wrenching 40 years, just can't stand a valve train beating itself to death.

Cool, it’s true that it’s better for the cam&lifters to run a tighter clearance at the expense or dwell time on the valve seat. All a balancing act.  What is the clearance hot at TDC, bearing in mind the factory markings for that are notoriously inaccurate to say the least.  Steel pushrods can be safely set at.002”, both intake and exhaust but I’m uncomfortable setting them that tight but haven’t had trouble doing so.

[SIR REAL ED]

I've always set clearances at TDC, if there's a standard baseline, why aim for something else?

I've read many times that it doesn't have to be set exactly at tdc as long as the valves are both loose, you're close enough;idk?

I'm having a hard time wrapping my head around your technique and the concept, but irregardless, isn't there a saying "noisy valves are happy valves" ?
 
fwiw

Kelly

I think it is "A clappy tappets is a happy tappets!"

I always set mine a thou or two greater than max spec.  As pointed out, time in contact with the head, is cooling time!

[chuck peterson]

I think your technique removed the worn spots on your rockers

Dave R in guzziology mentions it on high mileage bikes

The valve stem pounds a depression that sits masked by the width of the feeler gauge

That depression depth adds to your clearance when the feeler gauge is removed and bingo, too much clearance

My machine shop wouldn’t reface the rockers suggesting I’d lose hardening on the surface

Neat trick on the bottom of the cam, never heard of it

[John Croucher]

I think your technique removed the worn spots on your rockers

Dave R in guzziology mentions it on high mileage bikes

The valve stem pounds a depression that sits masked by the width of the feeler gauge

That depression depth adds to your clearance when the feeler gauge is removed and bingo, too much clearance

My machine shop wouldn’t reface the rockers suggesting I’d lose hardening on the surface

Neat trick on the bottom of the cam, never heard of it

The picture I posted above is and example of this wear. You would not see this without taking the rocker Arms off.  The feeler gauge would bridge this wear.

[moto-uno]

 On the occasion that I felt the feeler gauge and my feeling clearance were off , I'd get out my magnetic based dial indicator and
simply check the play at the end of the rocker arm ( over the valve stem ) and adjust as necessary , a nuisance , but hey how often
are we checking valve clearances after a few years of ownership ?  Peter