Valve lash, going bigger or smaller?

[thor_eyerdhal]

Hello,
Is valve lash going bigger or thinner with miles?

Some buddies on my french board are telling that lash become smaller (valve knocking and knocking on the seat=> valve become longer and go deeper in the seat..)

I am not agree, and think that lash is growinq with miles (if not, why some used motors are ticking ?)

 

[dannymax]

The way I understand it is, valve lash goes thinner or tighter with miles. The valve wears up into the head pushing the shim closer to the cam lobe and shrinking the tolerance.

 

[maleko89]

+1 Dan-o. In my experience exhaust valves go tighter......intakes usually stay close to the same but do tighten up a tad.

 

[Rusty McNeil]

I believe it depends on where the wear is, with the vmax the wear is usually the valve seats so the valve stem becomes closer to the lifter/cam and shrinks the clearance....Some bikes/cars the cam face or lifter is the part that wears and then the clearance becomes greater.......

 

[wlodek1980]

i've done quite a few clearance adjustments and typically they go tighter on kawasakis and suzukis, but bigger on hondas and yamahas. just my 2 cents. abviously there are going to be oddballs.

 

[SpecOps13]

The original engineering thought was that all the parts (Shims and Lobes) would wear as well as the seats so
the adjustment would stay the same.. Didn't happen that way. The seats on the Max will tend to wear faster...

For some reason a few VMaxer's have extremely high mileage and the valves have never needed re-shimming..:confused2:

 

[Rusty McNeil]

On my V65 the lash had to be re-set about every 3000 miles:bang head: The cam faces wore heavily making the lash get bigger....It had these wierd "Y" shaped rocker arms sort of like a push rod motor that allows one cam lobe to operate two valves.....

 

[satariel666]

The way I understand it is, valve lash goes thinner or tighter with miles. The valve wears up into the head pushing the shim closer to the cam lobe and shrinking the tolerance.

+1

Cam lobes, shims, lifter, retainers etc wears too but not at the level you would complain.

 

[Heretic]

I adjusted the valves on mine this winter. All the intake valves decreased in tolerance, some quite a bit. The exhaust all tended to be close to spec or just a tad tight.

 

[thor_eyerdhal]

Ok, thank you very much guys