Valve adjustment discussion...

[allstar71]

To start I just did a valve adjustment on my honda s2000 and decided that while it was fresh on my mind I would check the valves on my ski....much to my surprise they are VERY different. The sho motor is a much harder process which involves actually having to pull the camshafts and replace these valve pads with different thickness ones to bring it into spec. This is kinda crazy! makes a very simple process hard! On the honda engine you loosen a set screw tighten the screw and reset the set screw...recheck and move to the next one....seems like it would be hard to know which thickness pad you will need to bring it into spec? attached is a pic of my honda engine...

Instructions are on 5-64 of the fx sho manual. If you're interested...


I would like to hear from any of you that have checked the valves and are they holding spec? Also, how hard is it to determine which thickness pad is needed?


This post is strickly for discussion because I'm bored....

[SHOBiz]

It is very time consuming. And everytime I measured I got different clearances and got tired of buying shims to try to match up (That was prior to the kit in the store being offered). Just one of the reasons I said screw it and shipped the motor.

I think I was measuring all without any shims to get the total gap. Then it was a matter of simple math to get what was supposed to be the right shim by subtracting the proper clearance from the total without a shim then rounding up as defined in the shop manual.

My original head was still within spec after over 160 hours of good hard use. The new used head I have no idea as it was apart when I got it. Jim's getting the joy of setting that one up

[allstar71]

That's what I thought...it took me about 1.5 hours to do my honda. This looks as if it would take 4-5 hours to do it correctly.

How do you check the clearances with the cam's out? or do you do your measurements then adjust all per measurements then put the cams back in and check then pray that they are all right?

[SHOBiz]

Pull the cams, install the shims, reinstall and torque the cams, position the cams for the right valves, measure, rotate the cams for the rest of the valves and measure. Rinse and repeat over and over.

Thank God the valves on my 944 are hydraulic.

[fx160]

That's what I thought...it took me about 1.5 hours to do my honda. This looks as if it would take 4-5 hours to do it correctly.

How do you check the clearances with the cam's out? or do you do your measurements then adjust all per measurements then put the cams back in and check then pray that they are all right?

the cams need to be in to check the clearance, but you don't need to have the head on the ski
my old kawasaki drag bike had the same shim setup, and once setup the clearance's never changed
to check what shims it needed to start with i set the head up with soft valve springs (carbie springs) and the smalest clearance shims (only one side and cam at a time)
write all the numbers down do the math to work out what shim is needed retest then fit the proper valve springs test again then fit the head
sounds like alot of work but it was very easy and quick

[allstar71]

how accurate are the shims? you are dealing with thousandths of an inch. If you do your math right do the shims usually work out to be what you expect them to be?

how do they ever get out of spec? shims compress? cam wear down? or the plate that the cam presses on wear/compress?

If it were anything other than these things wouldn't you have a bad seal below?

[SHOBiz]

I would suspect the cams, valve ends and possibly buckets would be the wear point. The shims on my #3 that blew did get messed up a bit, but when I calipered them they were still spot on to the numbers on them.

Now let's wait for everyone to pop in and say the exact same thing

[fx160]

how accurate are the shims? you are dealing with thousandths of an inch. If you do your math right do the shims usually work out to be what you expect them to be?

how do they ever get out of spec? shims compress? cam wear down? or the plate that the cam presses on wear/compress?

If it were anything other than these things wouldn't you have a bad seal below?

for me there was some movement on initial bed in and then they were fine
but i never lasted more than 12 months before doing more mods
and yes if you do the math the shims work out every time
you do need clearance though to make it work
it's a bitch if you have no clearance with the smallest shim , which is why i assembled with soft springs as it was easy to pull the valve back out and tip the end also you could spin the cam by hand
or push the bucket down and change a shim to test (best to have a mate with an assortment of shims though to make it easy)
occasionally i had to tip a valve to suit a shim rather than waiting to get one in the right size

[oldskoolmc]

Pull the cams, install the shims, reinstall and torque the cams, position the cams for the right valves, measure, rotate the cams for the rest of the valves and measure. Rinse and repeat over and over.

Thank God the valves on my 944 are hydraulic.

That is the extreme long way of adjusting shim under bucket.

a few things:

1) Using good old pen and paper, you can measure all the valve clearances at once.

Use something like this: http://www.calamarichris.com/images/valveform.pdf

2) Shim kits can be bought anywhere. Don't waste time buying singles - get a kit.

3) Use a shop manual

It's not really that hard to do and it does take longer than doing rocker style but the intervals should be much longer between adjustments using shim under bucket.

[SHOBiz]

That is the extreme long way of adjusting shim under bucket.

a few things:

1) Using good old pen and paper, you can measure all the valve clearances at once.

Use something like this: http://www.calamarichris.com/images/valveform.pdf

2) Shim kits can be bought anywhere. Don't waste time buying singles - get a kit.

3) Use a shop manual

It's not really that hard to do and it does take longer than doing rocker style but the intervals should be much longer between adjustments using shim under bucket.

Been there done that.