A-series crank dampers

Vizard devotes a couple of pages to dampers in the later book (the big yellow one) and the answer briefly is yes. Inline cranks are shorter and have lighter flywheels though so the need to damp vibrations is not so pressing as on transverse engines and the resonant frequency will also be higher and so more likely to be above the actual rpm range anyway.

Dave Baker - Puma Race Engines

Thought the vibration occurred above the practical rev limit of an A-Series?

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To add to this I seem to remember the Coopr S type was the only type that actually did any good. Also fitting a rubber damped crank damper will never do any harm even if it is the wrong frequency.

Yes but the harmonics don't. Early TR engines are renowned for breaking cranks despite being low revvers. Crankshaft dampers help a lot. They can never be a bad point unless they break and that's rare. There will now be lots of people reporting damper breakages.

John