I noted a strange exhaust note during a recent track session in my stock '71 911T. I perceived a loss of power too but with a stock 2.2T, there isn't much to begin with. There was an obvious engine vibration at lower revs. I brought it in straight away (still under power) and noted significant valvetrain clatter from the right side of the car as I took off my helmet and got out. Thought I could isolate the noise to the intake side and shut the car down. I expected based on the noise to find a broken rocker but instead found a missing nut and swivel foot on the #6 intake side:
I last adjusted the valves about 18 months ago and have driven the car several thousand miles and several track sessions. No obscure valve noise, car was running great, etc. Looks like the valve stem is unharmed from what I can see thus far and the adjuster screw ball end also doesn't have witness marks.
Ideas to cause and/or where the nut and swivel foot might be found? Sustained high RPM running, somewhat elevated temperatures (this was a cool track weeeknd and temps stayed very reasonable)? I'm crossing fingers that both missing pieces might be resting directly below on the exhaust side under the rocker cover but I haven't opened that up yet. Wish me luck on that!
Sad part is that I'm building a 'hotrod' engine on the side so that I don't subject the #'s matching original engine to as much risk on the track......but it isn't completed yet and wasn't planning on going into the car probably until next winter. I also debated about adjusting/checking valves before this driving season begain in earnest but I decided to wait. Silly me!
Cheers,
Chet