What shim kit size range to get for valves?

[Rembrant]

The Hot Cams Kits just don't do the job, they are 90% out of the range you will be needing.

it seams like it is simpler to buy a kit, but really it's a waste of time and money, as will will ALLWAYS have to get one that doesn't come in the kit.

Hey MOB,

I have to disagree on the Hot Cams kits being a waste of money...they're actually quite handy if you do valve checks and adjusts often enough. You can buy two different range kits, and if you want you can buy specific sizes in refill quantities.

I used to try to adjust valves to some sort of level of perfection that wasn't actually required....it was a personal preference, nothing more, but it became increasingly more and more frustrating waiting on specific shims from the Kawasaki dealer with a set of cams laying on my bench that I wanted to put back in the darn bike. It's nice that the OEM shims come in the more refined 0.001" increments, but they're not always needed. Our local dealer(s) don't stock all the sizes...just a small handful.

Since the valve specs on most bikes are in the 4-5 thou range, the Hot Cams shims, which are in 0.002" increments, will be just fine for adjustments, assuming the valve is at the edge of the spec.

In my experience, I usually find between 4-8 valves that can be adjusted. Usually, half of them can be adjusted by simply moving existing shims around. In the end, I rarely ever need more than 3-4 "new" shims from a kit (or the dealer, whatever).

To add to this...I have made the second valve adjustment on two Kawasakis (one Z1000, and one C-14) that had previously had their valves adjusted at two separate Kawasaki dealers. Guess what I found inside them? Hot Cams shims...lol. No joke. (<---BDF likes this:)/

All I'm trying to say is...don't dismiss them as being completely useless...if I can find a shim or two that I need in the kit, so that I can snap the valve cover back on the bike in the same day...then having that kit is like money in the bank for me, and makes for a much more seamless job. A valve check and adjustment is a big enough job without having the bike down for several days while you track down the shims you need.

Do enough valve adjustments, and eventually you'll end up with a pretty decent supply of various sizes...assuming that you keep the OEM shims you remove, and refill the Hot Cams shims as you run out.

As always, YMMV.

[B.D.F.]

?? Not sure what you mean here but I have no opinion on any shims. They are merely hardened discs of metal that anyone can make (any manufacturer). No difference what brand as long as the thickness is what is needed. Nothing wrong with Hot Cams or any other brand of shim.

Brian

<snip>

To add to this...I have made the second valve adjustment on two Kawasakis (one Z1000, and one C-14) that had previously had their valves adjusted at two separate Kawasaki dealers. Guess what I found inside them? Hot Cams shims...lol. No joke. (<---BDF likes this:)/

<snip>

[Rembrant]

?? Not sure what you mean here...

I was pointing at the "No Joke" part...lol, nothing to do with you and your opinion of shims at all...lol.

[B.D.F.]

Ah, gotcha'.

 

Brian

I was pointing at the "No Joke" part...lol, nothing to do with you and your opinion of shims at all...lol.

[spatten]

So, those of you that have adjusted valves on this engine have only seen them go tight?  Has anyone seen them go loose too?

On my Honda Civic, I've been told to just run it and not worry about it, as the valves go loose and you'll hear them if they are out of spec.

My way of thinking is that stems, cams, and tappet surfaces wear increases tolerance.  Valve heads and seats wear decreases tolerances.  Generally, due to the specific valve train, one or the other tends to create tolerance changes primarily in one direction, but some engines seem to go both loose and tight on different valves, showing a balance in wear surfaces.

Not that it really matters, but I can't help but want to know more about this engine, as I need to work on mine soon enough.

[Rembrant]

I can't remember on the C-14's I have done...I'd have to dig out the shim maps, but for example, I just finished a 2008 Suzuki GSXR 750 last week, and found one exhaust valve a full 0.001" outside of the tight spec, and one intake valve all the way to the loose end of the spec.

Seems to me that the exhaust valves are usually all on the tighter side, and the intakes are more often where you'll find a loose clearance. I can't say why...just thinking back is all.

Maybe somebody else can chime into why this happens.

I'm not saying that it always does...but it's somewhat common IIRC.

[B.D.F.]

There is no rule, but a basis for valves tightening rather than loosening as they wear.

If an engine is used fairly lightly, the wear does seem to be about even between the valve train mating components (increasing clearance) and the valve seat and valve face (decreasing clearance). But, the harder an engine is used, i.e. putting out a lot of power at high RPM's, the valve train wear stays about constant but the valve seat and valve face wear increase due to contact speed and heat increase. So, the trend is generally toward balanced movement (no change in clearance) and tightening clearances.

A gentle correction if I may: the space left in things so they fit is clearance, not tolerance. Tolerance is the allowable change in something like clearance. For example: the clearance on valve lash may be 0.006" to 0.008", and in that example the tolerance would be 0.002" or the total allowable change in clearance.

Brian

So, those of you that have adjusted valves on this engine have only seen them go tight?  Has anyone seen them go loose too?

On my Honda Civic, I've been told to just run it and not worry about it, as the valves go loose and you'll hear them if they are out of spec.

My way of thinking is that stems, cams, and tappet surfaces wear increases tolerance.  Valve heads and seats wear decreases tolerances.  Generally, due to the specific valve train, one or the other tends to create tolerance changes primarily in one direction, but some engines seem to go both loose and tight on different valves, showing a balance in wear surfaces.

Not that it really matters, but I can't help but want to know more about this engine, as I need to work on mine soon enough.

[spatten]

That also makes sense, as exhaust valves run far hotter than intake valves and the seats and faces should wear quicker, tightening the CLEARANCE. 

[spatten]

I like this site a lot.  On the Buell site this thread would already have turned Democrat Vs. Republican.  I like this tech talk quite a bit.  Really informed people here too.

[B.D.F.]

Well, the reason the exhaust valves have more clearance is because they get much hotter and therefore expand a lot more. Remember, we are setting the valve lash cold but it is actually used when the bike is at normal running temps. or even higher.

Again, as power increases, so too does the temperature difference between the intake and exhaust valves. As the exhaust valves are always hotter, they will always be longer in proportion to their cold temperature; expansion is a direct result of temperature. So the greater clearance on the exhausts is to allow them more room for expansion.

Now for the odd part: usually if a valve gets to zero clearance or less (it can be less if there is a gap in the valve train throughout it's rotary travel) a valve will never seat (known as 'hanging a valve'). As the intake valve cools itself much more by using contact with the valve seat than the exhaust valve does, when both valves hang open, it is usually the intake valve that ends up burned. You would not think so but that is typically what happens. It is an odd world.

Brian

That also makes sense, as exhaust valves run far hotter than intake valves and the seats and faces should wear quicker, tightening the CLEARANCE.

[theAmazingKickstand]

Thanks for everyones replies.
After some thought I think I'll be getting rid of this bike as is and getting a brand new one (hopefully)