I noticed two flights prior to this day that the cabin heat wan't that effective and put it down to the really cold weather we were having. I then removed my cowls to start the 50 hour service and discovered the sight in photo one.
The top end caps had disappeared as rods sheared at SS nuts. I must have overtightened the locknuts. I had previously spoken to Rick Robbins (maker of the muff) and he suggested SS shim between inside of end plate and exhaust. I used the1/2" SS straps Vans supply for supporting 2" ducting as it was unused - 2" peice. This shim seemed to do the trick and I certainly did not overtighten the nuts this time Thanks to John Brady (UK RV-8 Builder) for loaning parts whilst they travel from USA.
Moral of the tale here is (though normally I am fairly good at investigating issues) - if something is not right - investigate it.
