A-series crank dampers

Can someone settle a question that's gnawed away at my subconscious for 30
years? Is a crankshaft damper of any benefit on an in-line A-series engine?
They are highly recommended for transverse engines (eg Vizard).

Subject: A-series crank dampers
From: "Les Rose" **lesrose@**ntlworld.com
Date: 07/07/03 11:32 GMT Daylight Time
Message-id: <%YbOa.4308$ju6.78626 (AT) newsfep4-glfd (DOT) server.ntli.net

Can someone settle a question that's gnawed away at my subconscious for 30
years? Is a crankshaft damper of any benefit on an in-line A-series engine?
They are highly recommended for transverse engines (eg Vizard).

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 (www.pumaracing.co.uk)
One's taste in music is the key that fits the lock of each individual person's
psyche.

In article <%YbOa.4308$ju6.78626 (AT) newsfep4-glfd (DOT) server.ntli.net>,
Les Rose <**lesrose@**ntlworld.com> wrote:

Can someone settle a question that's gnawed away at my subconscious for
30 years? Is a crankshaft damper of any benefit on an in-line A-series
engine?

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

--
*Rehab is for quitters.

Dave Plowman dave.sound (AT) argonet (DOT) co.uk London SW 12
RIP Acorn

"Dave Baker" <pumaracing (AT) aol (DOT) comma> wrote

Subject: A-series crank dampers
From: "Les Rose" **lesrose@**ntlworld.com
Date: 07/07/03 11:32 GMT Daylight Time
Message-id: <%YbOa.4308$ju6.78626 (AT) newsfep4-glfd (DOT) server.ntli.net

snip

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.

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.

"Dave Plowman" <dave.sound (AT) argonet (DOT) co.uk> wrote

In article <%YbOa.4308$ju6.78626 (AT) newsfep4-glfd (DOT) server.ntli.net>,
Les Rose <**lesrose@**ntlworld.com> wrote:
Can someone settle a question that's gnawed away at my subconscious for
30 years? Is a crankshaft damper of any benefit on an in-line A-series
engine?

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

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