Page 1 of 1

Whirriing noise when running over 1500RPM

Posted: Wed Feb 21, 2024 17:32
by Zaphod
Now I have oil pressure I seem to have a new problem.
The engine displays the symptoms of a cam belt that is too tight and make a loud whirring noise when the revs go much above idle. I have run it with both the alternator belt and PAS belt removed, and that makes no change. My Burroughs guage shows the belt to be tensioned at somewhere between 90 and 95 (Crank at 30 degrees BTDC) which I believe is within the factory range. The frequency test gives a results in the range of 103-108hz using the gates belt app on the phone. I did change the tensioner bearing which was a 'Breda Lorett' item for a new Flennor bearing in case that was a problem, however it has not solved the issue. There is a very low volume high pitched whine at idle, but this could just be air entering the carbs? I do know the plastic cover under the distributor cap is missing, the noise seems to be more central than at the front of the engine. It reminds me of a dry ball race

Re: Whirriing noise when running over 1500RPM

Posted: Thu Feb 22, 2024 12:05
by rbgosling
You definitely have the correct cam belt, with either the trapezoidal or semi-circular teeth profile to match the pulleys?