valves...i feel stupid...

[crazy steve]

how often does everybody on here actually check their valve shims....

Some of yours are at minimum spec, so you'll want to check again before too long; say about 3-5K miles. It also depends on which 'spec' you run; the 'early' ('78-79) intake clearance is .006-.008", the late is .004-.006". All use .008-.010" for the exhaust. If set to the early spec and at the high end of the range, checking every 10-15K will probably be ok. The valve clearances don't close up that quickly generally, but if your top end gets quiet, it's time to look...

The valves shed heat by the amount of time they're on the seat, so tighter clearances reduces that and can increase wear. But these motors are pretty bulletproof... the XJ I'm rebuilding was down to .004" or less on all the valves and showed poor compression and ran poorly. Reshimmed the valves and compression came right back up... I'm not recommending you let them go that long, but that shows what they can tolerate.

[mack]

Noise

Just redid all my shims on my SF yesterday, put them all at the upper limit. Man is it ever noisy now. On the other side of the coin though, it is running likeit did thirty years ago. Very smooth and lots of get up.

[airborneXS]

after struggling with the damn motion pro valve adjustment tool, i went ahead and just puuled the cams...these are the measurements i came up with...

Valve: feeler clearance: shim #:

1E: .20mm 280
1I: .13mm 265

2E: .20mm 285
2I: .10mm 270

3E: .20mm 285
3I: .15mm 270

4E: .20mm 285
4I: .13mm 280

ive tried reading the valve chart but im just not seeing it.....

[bikerphil]

All your exhaust valves are in spec but at the tight end of the scale. They are all at .008" and the scale is .008"-.010", by dropping all your exhaust shims one size smaller (.002"), that would put you on the loose (safe) side of the scale.

1I I would go 1 size smaller, that would put you at .007"
2I I would go 2 size smaller, that would put you at .008"
3I I would go 1 size smaller, that would put you at .008"
4I I would go 1 size smaller, that would put you at .007"

I have calculated this using the specs for the 78-79 motors which is:

IN: .006"-.008"
EX: .008"-.010"

ive tried reading the valve chart but im just not seeing it...

Me neither, lol

[airborneXS]

thanks, i found a better chart that i was able to get what shims i needed right after i posted that, just needed to look harder...my bad...thanks though....

[bikerphil]

thanks, i found a better chart that i was able to get what shims i needed right after i posted that, just needed to look harder...my bad...thanks though....

No problem, I needed the practice.