Severe Rattle from Top of Cylinder Head

[Suzuki_Don]

John, Wally, Daniel; I notice in the chart John supplied the 222, purple, low strength has an upper temperature limit of +150degC. Do you guys think the temp of where the cam cap bolts thread in would be above that temperature?

thoughts.

[49er]

John, Wally, Daniel; I notice in the chart John supplied the 222, purple, low strength has an upper temperature limit of +150degC. Do you guys think the temp of where the cam cap bolts thread in would be above that temperature?

thoughts.

Don, I wouldn't put any Loctite on those cam cap bolts. Many people over torque them, only to damage the threads or break the bolts. Ali expands at a greater rate than steel, so over torqued bolts will get higher loads once the expansion rate increases, during hard riding.

Is it possible that you got interrupted when tightening them the first time? IMO, you would need quite a lot of vibration to cause those bolts to back off.

[7981GS]

John, Wally, Daniel; I notice in the chart John supplied the 222, purple, low strength has an upper temperature limit of +150degC. Do you guys think the temp of where the cam cap bolts thread in would be above that temperature?

thoughts.

I would think that the combustion chamber area would get way over 302 Fahrenheit or 150 Celsius.

And yes, probably not a good idea to use any sealant on the threads.


Daniel

[Suzuki_Don]

Don, I wouldn't put any Loctite on those cam cap bolts. Many people over torque them, only to damage the threads or break the bolts. Ali expands at a greater rate than steel, so over torqued bolts will get higher loads once the expansion rate increases, during hard riding.

Is it possible that you got interrupted when tightening them the first time? IMO, you would need quite a lot of vibration to cause those bolts to back off.

Ian, I think you could be correct. Before I checked my shim clearances I decided to make sure the cam caps were properly seated by re-torquing the cam cap bolts. All were fine except for this one which was loose. So it is quite possible that I was called away and did not fully tighten this last one. Also it was on the intake cam which would make sense as well as when doing the cam timing the intake cam goes in and is timed last and it would make sense that those caps would be tightened last of all.

I am having a rethink about using the Loctite on these bolts and think I will just recheck the torque on them and leave them at that.

I see Daniel is of the same opinion.