Quote:
Originally Posted by Makko
Oh, the woe on the Super P's: 9RD90 with the rotary exhaust valves......
Rgds.
Dave
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'Remember there were issues with those exhaust valves on the RD76s but the details escape me ; seals? blades seizing?
Have better (I mean clearer
) memories of the semi-rotary exhaust vales on a 12RSAD76. They were actuated by a rod that passed across the engine and were driven by excentrics on the fuel pump camshaft which was at cylinder head level. Truth was that the valves weren't huge problem but continually slackening tie rod were as you had to release the valve drive rods to access the tie rod nuts.
This engine had an inner and outer set of holding down bolts and the inner ones were particularly prone to slackening or fracturing. However, we found a good technical solution to that problem - we left them all slack
As far as I'm aware the engine failed to punch it's way through the tank top during the rest of it's life.