TOPIC:

Nessism wrote: With the Kawasaki method sometimes the adjacent valve is pushing up and sometimes not.

I don't follow what you mean. The cam lobes next to the ones being measured are either pointing down, or toward the the other camshaft. That means the valve should be getting pressed.

Kaw FSM summarized:
When #1 is at TDC on its fire stroke, measure 1 and 3 intake. (Intake 2 and 4 will be pressing.)
When #2 is at TDC on its fire stroke, measure 2 and 4 exhaust. (Exhaust 1 and 3 will be pressing.)
When #4 is at TDC on its fire stroke, measure 2 and 4 intake. (Intake 1 and 3 will be pressing.)
When #3 is at TDC on its fire stroke, measure 1 and 3 exhaust. (Exhaust 2 and 4 will be pressing.)

Which of the above positions did you find an adjacent valve not being pressed?

If you did not find an adjacent valve being pressed, I suspect you may have been measuring the wrong valve. This could explain your results. (I just checked this on a 550 head with cams and valves installed and every measured lobe has an adjacent pressing lobe.)

(I'm not sure if it matters, but I'm using a Gpz head and cams, which have a few more degrees duration than the standard 550. I don't think the standard Kz's lesser duration would be enough to let the adjacent lobe not press.)

Also, we should probably clarify "consistency", as there are two factors as I see it. One is to be consistent with how the factory designed the measurement to be taken, and the other is to get consistent (repeatable) results.


I think we are in agreement on the following:
The point-away method suffers from deficient repeatability, since there is no timing mark to align. (And we already know different positions on the base circle can yeild different clearances.) In experiments from years ago, I recall I could easily get results to be different by .001" to .002", as I think you also found. At most, that is basically one full shim increment.

Kray-Z wrote: Hey, this is getting absolutely nuts!

Any of the FSM methods, and pointing the lobe 180 deg. away, will work just fine as long as you are sure you are on the base circle of the damn cam! ....

That's not really what we're discussing anymore.

We are now talking about measurement tolerance. If you want to presume that the camshaft does not move within the bearings, and the camshaft does not flex, by any significant amount, fine.

We don't agree with that. Ed is trying to come up with an idea of how much flex and movement actually exist, and how they affect the final measurement in the 3 different measurement procedures.. Among all of the different methods, he saw a range of results possibly spanning .002". (Which is about the amount I recall seeing when I last experimented with this.) If that is +/- .002". That covers the range of two shim sizes. If it is only +/- .001", then it's still covers the span of a full shim size. It would be nice to get the measurement to within one shim size or much less.

It's never really about whether something is perfect or not. It's always about how much does it deviate from perfect.

smiles.....
what is the purpose of valve clearance?
the purpose is the valve is firmly seated on the valve seat for about 2/3 to 3/4 of the rotation of the cam, no matter how hot the engine is.

So, technically, .002 would be fine, but you can't guarantee when you measure .002 that it will be that same .002 at all temperatures. so, you give it a bit more.
air cooled aluminum heads tend to expand more than water cooled cast iron heads, so they tend to get more clearance. push rod motors have other problems, so they get special clearances depending on the push rods being steel and the cylinders being steel or aluminum.
if the clearance gets to zero, bad things happen.
if the clearance is too much, you lose duration, and it gets noisy, and it might beat up the valve stem.
in a perfect world the base circle of a cam would be equidistant (circular) so it wouldn't matter. sounds like the cams aren't that good, or there is crap in there, or who knows.
consistency doesn't matter as long as the valve gets to spend time firmly planted on the seat no matter how hot the engine.

loudhvx wrote:

Nessism wrote: With the Kawasaki method sometimes the adjacent valve is pushing up and sometimes not.

I don't follow what you mean. The cam lobes next to the ones being measured are either pointing down, or toward the the other camshaft. That means the valve should be getting pressed.

With cylinder #1 at TDC the FSM calls for checking #1 & #3 Intake.

#2 intake cam lobe is point straight down at the valve, depressing it significantly. This will influence the #1 measurement.
#4 intake cam lobe is pointing forward, only slightly depressing the valve. This won't affect the measurement of #3 very much if at all.

I consider this inconsistent. The cam is pushed up by #2, but but only minimally so by #4.

If you rotate the engine forward until #4 is heavily depressing the valve and then measure #3, the measurement is different by .001-.002".

Some of the other FSM cam positions are similar.

Oh, and regarding this comment: "And we already know different positions on the base circle can yeild different clearances."
The base circle is just that, a circle. Technically, you can measure the clearance anywhere on the base circle, EXCEPT that the position of the adjacent valve has an influence so the results will vary based on that.

Nessism wrote:

loudhvx wrote:

Nessism wrote: With the Kawasaki method sometimes the adjacent valve is pushing up and sometimes not.

I don't follow what you mean. The cam lobes next to the ones being measured are either pointing down, or toward the the other camshaft. That means the valve should be getting pressed.

With cylinder #1 at TDC the FSM calls for checking #1 & #3 Intake.

#2 intake cam lobe is point straight down at the valve, depressing it significantly. This will influence the #1 measurement.
#4 intake cam lobe is pointing forward, only slightly depressing the valve. This won't affect the measurement of #3 very much if at all.

I consider this inconsistent. The cam is pushed up by #2, but but only minimally so by #4.

Ok, thanks for clarifying. When you said "sometimes not", it implied not at all, which clearly is not the case.

Nessism wrote: If you rotate the engine forward until #4 is heavily depressing the valve and then measure #3, the measurement is different by .001-.002".

My results differ from that. I get soemwhere less than .001". Feelers always round down from the actual distance.

Intake:
1....... 2....... 3....... 4.......
.005h .007s .005s .006h FSM method. h means adjacent pressing hard. s means adjacent pressing softly.
.004s .007h .005h .006s moving camshaft slightly to get alternate h and s on adjacent lobe.

Exhasut:
1....... 2....... 3....... 4.......
.008h .011s .009s .008h FSM method. h means adjacent pressing hard. s means adjacent pressing softly.
.008s .011h .009h .008s moving camshaft slightly to get alternate h and s on adjacent lobe.

#1 intake .004s was very loose, but could not get .005 to go.
#4 exhaust .008s became much looser, but still could not get a .009 to go.

My results show most readings came out about the same. Only one actually changed, and one became noticeably looser.
Due to the nature of using feeler gauges always rounding down, they mask the actual difference. But if the difference was always .001 or greater, all of the measurements would have changed by a full feeler size. They did not, so the difference is somewhere under .001 when going from adjacent pressing hard versus adjacent pressing soft.

A hard pressed valve is somewhere around halfway pressed. A soft pressed valve is about a quarter pressed. Only a few degrees makes the difference since the valves are moving rapidly in that range.

Nessism wrote: Oh, and regarding this comment: "And we already know different positions on the base circle can yeild different clearances."
The base circle is just that, a circle. Technically, you can measure the clearance anywhere on the base circle, EXCEPT that the position of the adjacent valve has an influence so the results will vary based on that.

Yes, that is what I meant. Other lobes will influence the measurement, so we can't assume (even though we would intuitively like to assume) we can measure at any point of a base circle and get the same measurement.

I also measured the difference between the Suzuki method and the FSM method, but only on a couple valves since I was running out of time. That also yielded differences of about one feeler size, so less than, but up to .001" differences.

So adding the possible permutations, the FSM and Suzuki methods may give results different to within .002" or less.

Even if the Suzuki method is more consistent, valve-to-valve, (I haven't had time to check that yet, but I'm willing to go along with that) the results between Kawasaki method and Suzuki method differ by possibly a full shim size (.002").

The range, on the 550 clearances, only spans two shim sizes, meaning, at most, there are only three possible shim sizes that are acceptable for a given valve, and more often, there will only be two acceptable sizes.

So the question is, which method gives the clearance results that Kawasaki expects? I would still recommend following the Kawasaki FSM when working on a Kawasaki.

All of the FSM and Suzuki method values were repeatable, though, which, in itself, is probably good enough, at least in not pulling out hair. The last time I investigated the point-away method, it gave non-repeatable results since there were no real marks to line up. That was disconcerting. Plus with the point-away method, it means some valves will be fully pressed. (The lobes on a camshaft are pointed at 90 degree intervals.)

drmiller100 wrote: smiles.....
what is the purpose of valve clearance?
the purpose is the valve is firmly seated on the valve seat for about 2/3 to 3/4 of the rotation of the cam, no matter how hot the engine is.

So, technically, .002 would be fine, but you can't guarantee when you measure .002 that it will be that same .002 at all temperatures. so, you give it a bit more.
air cooled aluminum heads tend to expand more than water cooled cast iron heads, so they tend to get more clearance. push rod motors have other problems, so they get special clearances depending on the push rods being steel and the cylinders being steel or aluminum.
if the clearance gets to zero, bad things happen.
if the clearance is too much, you lose duration, and it gets noisy, and it might beat up the valve stem.
in a perfect world the base circle of a cam would be equidistant (circular) so it wouldn't matter. sounds like the cams aren't that good, or there is crap in there, or who knows.
consistency doesn't matter as long as the valve gets to spend time firmly planted on the seat no matter how hot the engine.

Seated for 2/3 to 3/4 cam rotation? Where do you get that?
The valve, on a gpz 550, is seated for less than 1/2 of a cam rotation when using zero checking clearance. Even with the normal clearance, it's far less than 2/3.

Yes the head expands, but the valve also gets longer, and the valve gets much hotter. In the 550, the clearance gets smaller when the internal engine parts are hotter, as in going at highway speed. But some report on the 650, that the clearance gets bigger with heat.

You can't assume cams are ridgid and perfectly straight. There is no such thing as a solid material that does not bend, and not even a laser is perfectly straight. Gravity bends light.

loudhvx wrote: All of the FSM and Suzuki method values were repeatable, though, which, in itself, is probably good enough, at least in not pulling out hair.

For what it's worth, I'm going with the Suzuki method. This way I know that every valve will be measured such that the adjacent valve will never influence the measurement. We can not say this is the case using any other method.

Yes, splitting hairs.

The other thing I've decided is to target the middle-lower half of the adjustment range. The 750/4 bikes (like mine) use the range from .10 to ,18mm, but I set all my valves at .13 to .15mm. The Suzuki method if anything will measure a little tighter, so targeting the lower end of the range makes sense to me.

Actually, with aiming for mid to lower end of the gap range, then we'd be in total agreement on the Suzuki method.

By my very rough estimate, it would be more or less the same as aiming for the middle range of the Kawasaki method.

This thing has been hammered to death but carry on.
Steve

loudhvx wrote: Actually, with aiming for mid to lower end of the gap range, then we'd be in total agreement on the Suzuki method.

By my very rough estimate, it would be more or less the same as aiming for the middle range of the Kawasaki method.

With the Kawasaki method 1/2 of the valves will run tighter than what the measured clearance would suggest. Shouldn't be a problem per say though as long as they measure in spec.

loudhvx wrote: [

Seated for 2/3 to 3/4 cam rotation? Where do you get that?
The valve, on a gpz 550, is seated for less than 1/2 of a cam rotation when using zero checking clearance. Even with the normal clearance, it's far less than 2/3.

Yes the head expands, but the valve also gets longer, and the valve gets much hotter. In the 550, the clearance gets smaller when the internal engine parts are hotter, as in going at highway speed. But some report on the 650, that the clearance gets bigger with heat.

You can't assume cams are ridgid and perfectly straight. There is no such thing as a solid material that does not bend, and not even a laser is perfectly straight. Gravity bends light.

my apologies on the first sentence. I should have said "2/3 to 3/4 of CRANKSHAFT rotation". Implicit is the crank goes around twice for each rotation of the cam.

fwiw, gravity does not bend light. Gravity bends the space/time continuum. Light goes "straight", but the universe gets bent..

btw, so you adjust your valves so they are PERFECT (whatever that means),. Drive it 1000 miles. the valves will no longer be perfect. You will be riding a motorcycle that is out of specification. You will be riding on worn tires, and worn brakes, and there will be dirt all over it.

Nessism wrote:

loudhvx wrote: Actually, with aiming for mid to lower end of the gap range, then we'd be in total agreement on the Suzuki method.

By my very rough estimate, it would be more or less the same as aiming for the middle range of the Kawasaki method.

With the Kawasaki method 1/2 of the valves will run tighter than what the measured clearance would suggest. Shouldn't be a problem per say though as long as they measure in spec.

Yes, but the amount is so small based on my measurement, it's likely statistically insignificant.

Since we can't really measure less than .001" accuracy, without investing in many more feelers, we can only measure the difference based on statistics. Out of 8 valves, it affected the outcome on only one. So if we extrapolate (albeit, admittedly, with a very small sample in this case) and assume a uniform, random, distribution of sizes, the difference would be about 1/8 of .001".

If two results had changed it would make it about 2/8 or 1/4 of .001". So I think it's fairly safe to say it's less than .001". If it was .001" or more, all of the results would have changed, obviously.