setting valve clearance

[louloupa]

Do you know how is setted the valves on the M8 ?   

[rigidthumper]

No adjustment available on the stock valve train. The system uses hydraulic lifters to take up any slack.

[rbabos]

With rockers on, one valve should have roughly about .002 - .005 clearance with the other foot touching. Hydros will only sense the longest valve from there. Realisticly the only thing that can happen is one developing too much clearance like in around .008 where it will be audible. A valve held open cannot exist due to the lifter sensing the valve that applies pressure to the lifter first. How to adjust, well valve seat depth altering valve stem protrusion and or rocker foot grinding.
Ron

[louloupa]

Each valve must be setted separatly . So, it is impossible to use hydraulics lifters .

Maybe ,there are calibrated tips between the rockers ans the valves .
As this picture :
[attach=0]

[Hybredhog]

    I suspect and hope as someone will build a rocker with 2 mini hydraulic tappets built in. Someone brought up a picture of a rock that Kawsaki uses that is like this. I'm just wondering if there'll be enough oil pressure up there to run them?

[HV]

There is a procedure for checking the Valve Lash on a M8

[SP33DY]

Maybe the MOCO or the aftermarket will come out with lash caps of varying thicknesses.

[HV]

3.

Allow lifters to bleed down. When lifters have bled down, pushrods can be rotated by hand.
NOTE

Do not rotate crankshaft until lifters have bled down. Rotating crankshaft sooner could result in valve-to-piston contact resulting in damage.

4.

Check valve lash after lifters have bled down.[/color]a.
Position crankshaft at TDC of compression stroke. All valves will be closed.b.
While holding rocker arm against valves, attempt to slide a feeler gauge between each valve stem tip and the rocker arm.c.
The maximum allowable lash on a common rocker arm is 0.2 mm(0.008  in). A measurement in excess requires disassembly and repair of cylinder head assembly.

[/font][/color]

[Karl H.]

Reading this thread might be of interest:
http://harleytechtalk.com/htt/index.php/topic,93345.msg1079076.html#msg1079076

Karl

[kristian]

During the rumors and info coming out slowly, i for sure thought that a ball and cup pushrod would be used in this case but a solid its is.  Anyways, not the greatest setup!

[rbabos]

Each valve must be setted separatly . So, it is impossible to use hydraulics lifters .

Maybe ,there are calibrated tips between the rockers ans the valves .
As this picture :
[attach=0]

No, only one valve needs to be less then the other with hydraulics. One will have 0 lash, the other about .002-.005 tip clearance as a nominal setup. While HD didn't bother with shims, adjusters etc, what they have will work quite well.More of a pain to set up when heads/valves are worked on then just popping in shims like in the pic but adjustment periods will be extremely long in time. For most a life time. Then you can either sink a valve in a couple thou more or touch up the rocker foot to regain that one valve tip clearance. .002-.003 won't make a rat's where you chose to do it. Keep in mind this is only needed if the difference between the two exceeds .008. At that point it will be a bit more noisy. At no point in this hydraulically controlled setup can a valve be held open to cause a leak. The tightest it can get is 0-0. Should over time one valve sink in .002 for example, it is now the 0 lash valve and the other will have .002 clearance. While I generally don't have a lot of good to say on some HD designs and obviously this is the cheap ass way to do things compared to traditional adjustments commonly seen, it is simple and effective.
Ron

[jsachs1]

I believe there will be adjustable rockers relatively soon.
From what I understand, if the heads come off for repair, the MoCo has a measure and grind process to equal the installed heights of the pair of valves in that cylinder.
I should have info on the depth of valve stem hardness in the next weeks.
John

[N-gin]

Adjustable rocker tips, on the valve stem side, are nothing new. As we all know. However they are installed on solid designs usually. I don't see an issue with hydraulic designs.. I'll bet Baisley will have a solution before long. His rocker are works of art.

[rbabos]

Adjustable rocker tips, on the valve stem side, are nothing new. As we all know. However they are installed on solid designs usually. I don't see an issue with hydraulic designs.. I'll bet Baisley will have a solution before long. His rocker are works of art.

I don't either and correct on the solid lifters needing all the extra crap to set clearances. Head porters or anyone who services the valves need to be more exacting now in protrusions.
Ron

[guppymech]

I'm bumping this thread for discussion.  All the MoCo had to do is make one rocker tip adjustable to correct for valve wear over the engines service life. I don't understand how the final rocker arm design made it through to production.  This is how Yamaha  addresses this issue.

[Karl H.]

I'm bumping this thread for discussion.  All the MoCo had to do is make one rocker tip adjustable to correct for valve wear over the engines service life. I don't understand how the final rocker arm design made it through to production.  This is how Yamaha  addresses this issue.

See reply #8 

Karl

[HD/Wrench]

Just checked the stock springs 56-66 is spec all of these feel into that range , per the book it states that .008 ( variation between valves pairs operated by a common rocker arm ) VSP max 1.752.  Adjustable tips sure why not seems that it has worked for other motorcycles for what 50 years or more .


Untitled by GMR Performance, on Flickr

Untitled by GMR Performance, on Flickr

Untitled by GMR Performance, on Flickr

Untitled by GMR Performance, on Flickr

[guppymech]

I'm bumping this thread for discussion.  All the MoCo had to do is make one rocker tip adjustable to correct for valve wear over the engines service life. I don't understand how the final rocker arm design made it through to production.  This is how Yamaha  addresses this issue.

See reply #8 

Karl

I read through that thread and a lot of thoughtful responses where given, I was intrigued by the diesel guy who said 4V diesels don't use adjusters any more.  On the whole I'm glad the guys on this forum (I'm a new member) are talking about this.  On some other forums I belong to they're more interested in the latest skull doodads.

[rbabos]

With solids adjusters are a must but in a hydraulic lash control system like this, all adding one adjuster will do is free up a bit more manufacturing slop, offering a way to bring the valve clearances within spec if variations between valves is off a bit more then norm. .008 is a very liberal slop I might add. I'd prefer much less, knowing it would operate just ducky at even .001
Ron