anyone (preferably local.. dc/md/va) got one of the 2.15mm shims i can borrow so i can figure out what sizes i need to order? i could pick it up, or maybe someone could mail me one to use? pulled the valve cover off today, and my .04in feeler won't fit under ANY of the cam lobes.
thanks,
dan
hope you mean .004" strip
der.... yeah.
ummm
I *really* hope you mean .04mm
because .004" == 0.1016mm, which would be .02mm over the allowed clearance, and *shouldn't* fit.
Be careful when you use the 2.15mm shim, make sure you rotate the engine 5 or 6 times with it in to force out as much of the oil from under it as possible, so it doesn't float on top of it and decrease your measured clearance.
good luck, and let us know how it goes! I did that maintenance recently and found mine to be much further off than anyone could reasonably expect, but WOW it runs better now =]
man... i don't even know anymore. it was the smallest one i had, which was one bigger than the minimum spec. i'm having a brain fart. :dunno:
you might want to check that. =] if a .10mm blade doesn't fit, that just means your clearances are probably not too *big*.
if a .04mm blade doesn't fit, chances are good that your clearances are too small.
I have heard it speculated that if the shim bucket rotates freely with the cam in "measurement" position, your clearances are probably not too small. It would mean you have at least *some* clearance, and I think the biggest problem is when you have *no* clearance.
However, when the engine heats up, the clearances shrink (metal expands) if I'm not mistaken... so I guess it depends on how close to spec you want it.
Just a few suggestions.
OK for the last time... Clearances in the Gs and most other amuminum motors... goes up as it gets hotter.
This is why...
The aluminum of the head also gets hot, so the distances between the valve seat and the cam end caps increases, and its aluminum so it expands a lot more than steel.
Now to the valves - the valveface, to the stem tip increases... as in valve gets longer, the cam diamater also gets bigger... so those to do want to close up the gap, but they are steel... and hence expand less than aluminum. So clearances go higher at full operating temp. Now the only twist to this tale is... the valve seats get to the temperature first, the cylinder last... for that reason running it tight is bad. There may be a small window where its too tight to close.
My virago 535 was this exact way.
Cool.
Srinath.
I bow before the wisdom of the expert =]
Then it sounds like chances are if the shim bucket rotates freely, even if your feeler blade doesn't fit under, as long as the clearance isn't too *big*, you're probably good?
but only if it rotates *freely*.
check that feeler blade width
Also may want to make sure you get the right size you need by measuring with micrometer or similar device. When I did my valves I went by the size labeled on the shim and just experimented with other shims that were only one or two sizes different according to label.
Of course this doesn't take into the shim wear into consideration.
ASLAM.
and just one other thing to consider, on that note, is that sometimes the feeler blades aren't really the width they claim, so if you measure the shim with a micrometer/caliper, check the blades too.
we had some that were pretty far off. =]