Here is the story I was told many moons ago. I have no facts to back
the story up.
Once upon a time when British automotive engineers developed their
engines they actually ran harmonic vibration tests on them. As time
went by, these companies got gathered up into British Leyland and the
data for the various engines got pooled into one repository with somehow
survived the demise of British Leyland.
I've been told that the folks who wanted the TR four cyl engine to turn
faster than 5200 RPM without breaking managed to gain access to the
crank harmonic data for all the companies that used to be in BL and
compared them all with the TR's chart. They then picked a harmonic
dampener for a crank that had curves that most closely matched the TR
crank's curve. Which happened to be an MG.
spamiam@comcast.net wrote:
> Scott, I did a little investigation into this question. The reality is that
>the modes of vibration are sufficiently complex that the dempeners were
>selected by trial and error. It was impossible to accurately estimate all the
>factors and all you could do is try it and see.
>
> I added a dampener to my (former) TR4A. I got it from Cambridge Motorsports.
> They used an MGB dampener. I tried to see if they actually tested these
>things or just found one that was from an engine of somewhat similar size and
>one that would fit.
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