Why Would The Earlier 1100 SACS Engine....

[H2RICK]

have different valve clearances than the 1200 Bandit engine ???

I have the FSM's for both the GSX1100F (1988-94) and my 3G 1200.
The earlier manual shows 0.10 - 0.15mm for BOTH intake and exhaust...
but....
The 3G manual shows: Intake 0.10 - 0.15 mm Exhaust 0.18 - 0.23mm

Any insights out there from anyone ?? I would have thought that they'd be identical all the way through to the end but.....
apparently not.

[pmackie]

Hey Rick

I would have thought they would have been the same as well, so I can only speculate. Maybe:
- they found over time that the exhaust needed more clearance?
- newer exhaust valves are slightly different material, with different expansion characteristics?

It would be nice to know why.

[H2RICK]

I'd put my money on your second idea, Paul, but.....let's hear some more info on this weighty question. Inquiring minds want to know!!

[gyrogearcrunch]

Hey Rick

I would have thought they would have been the same as well, so I can only speculate. Maybe:
- they found over time that the exhaust needed more clearance?
- newer exhaust valves are slightly different material, with different expansion characteristics?

It would be nice to know why.

Perhaps it's because exhaust valves run hotter, so they expand more and need a bigger cold clearance, otherwise you'd end up with poor valve seating of exhaust valves at final operating temperature?