Bounced valves 996 engine

[jerryz]

 Bounced valves 996 engine
I have been asked to rebuild the heads on a Thai 996 that had belts snap , seems 2 inlets and one exhaust valve are bent the other 5 valves and the pistons and all guides all seem OK ...rockers are all good too ...the owner also wants me to replace all the 4 belt rollers and bearings I thought that only the bearings would be needed any opinions or tips on anything i may have missed here as i will be coming to UK in a couple of weeks and will buy the parts for doing the job later in the year .
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MONSTERMAN

[Speeddog]

I'd take a close look at the exhaust valve that's not bent (that had a bent mate).

Check the clearance between the top ring and it's groove on the piston that got hit.

I don't see any reason to replace the rollers themselves, but not a bad idea to replace the bearings.

Take a real good look at the guides for cracks.

[Langanobob]

Jerry,

+1 on what SpeedDog said about checking the guides for damage.  In order for the valves to bend they have to use the guides as a mini cheater bar.

For our timing belt data base, do you have any background info on what caused the belt failure? Number of miles on them, tension?

Thanks,

Bob

[jerryz]

probably poor maintenance ...the thai culture does not understand adhering to schedules.