Valve clearance?

[Anonymous]

When checking valve clearance, should the cam be in line with the valve, or square to the head.?

[Anonymous]

I'm asking this because the book says the lobe of the cam should be
perpendicular to the face of the head when reading a tappet clearance.

When checking my clearances I found that there is virtually no clearance with the cam in this position.

With the lobe in line with the valve stem, there is clearance between the cam and the shim.

Just thinking about this right now, if the cam was slightly touching the shim, it would have tendancy to open the valve under the hot operating temps.

This is probably a good reason to sneeze and spit back through the carbs wouldn't it. Especially if the intake valve was held open just slightly during the combustiuon.

The air coming back through the carbs is much warmer than what is going in. Is it possible that every time it does this that it is because the valve clearances are not set with the cam in the correct position?

[Jeff Tate]

Even though my bike uses screw type adjusters, I can't understand why the lobes should be perpindicular to the head. I checked my manual and it shows the lobe parallel to the valve. Remember , mine are not shim adjusted. It seems to me you'd want to be as sure as possible as to having the clearance at it's largest. Which should be with the lobe opposite the shim. When you check the clearances in the "lobe straight up" position, do your readings look reasonable? It's been a long time since I had a bike with shims. I'm kinda curious myself now.

[Anonymous]

im going to say that i never heard of adjusting valves any other way than with the camshaft base perpendicular to whatever type of follower or bucket you have in your engine ?????????????

http://www.howstuffworks.com/camshaft.htm

http://www.pelicanparts.com/techarticles/911_valve_adjust/911_valve_adjust.htm

http://www.morrowmarsh.ca/concours/techpages/valves.htm

[Anonymous]

The answer is, it doen't matter where you find the clearance, as long as there is one.
The manual gives you a procedure which has you checking some clearances in one pos and some in the other, just whichever is handy when you spin the crank.
In theory the cam "land", i.e. the part which doesn't open the valve, should be perfectly machined so that the clearance is the same all the way round, hence Suzuki believing that you can check the clearance in any pos.
In reality this isn't the case, and as the clearance on a GS1000(say) is only 0.03-0.08mm, you will get a clearance at one point and not the other.
The engine just needs to see the valve fully seated during the 180 degrees of the cams rotation at which the valve SHOULD be closed. The ideal I suppose is immediately at the point at which it should have closed, but you ain't gonna get this.
So as Big S says either parallel with the valve stem, or parallel with the valve face, but facing outwards. or presumably at any point in between.

[Anonymous]

im going to say that i never heard of adjusting valves any other way than with the camshaft base perpendicular to whatever type of follower or bucket you have in your engine ?????????????

Check the Suzuki Factory workshop manual for a GS1000.... and probably some other 8 valve GSs.

Or trust me....!

[Anonymous]

Ok mate i trust you -now how about correcting me with some information

[Anonymous]

You mean more than in my post above the one in which I corrected you?!

[Anonymous]

You mean more than in my post above the one in which I corrected you?!

I think Scotty (Slowpoke) is just pulling your leg. We forgot to give him his medication this morning, and now he's acting up.

BTW, what part of Sussex are you from? I'm an ex-pat Brit in Colorado now but spent some of my youth in Orpington and Sevenoaks, Kent.

Simon

[Anonymous]

I live in Worthing.
I used to live in Tunbridge Wells, and work in Sevenoaks. Also I used to sell copiers and Orpington was my patch.

Boulder is a good place, I spent 10 weeks there in '98. Loadsa rich student types...

If you're from Orpington, doesn't that make you a retired armed robber? 8)

[Anonymous]

You mean more than in my post above the one in which I corrected you?!

I think Scotty (Slowpoke) is just pulling your leg. We forgot to give him his medication this morning, and now he's acting up.

Simon

Oh no, now they got irony over there.

That was all we had left.

[Anonymous]

I live in Worthing.

......If you're from Orpington, doesn't that make you a retired armed robber? 8)

Who says I'm retired? If I was a retired crim, I'd be in the Costa del Sol.

Simon