jarrid_gross(at)juno.com wrote:
>
> Alpiners,
>
> I went to go and clank some cranks last night.
>
> I friend of mine brought along a 5 main, and a 3 main crank.
>
> We clanked away!
>
> The 5 main sounded better than the 3 main did.
> The 3 main crank sounded dead in comparison.
>
> We think the 3 main was cracked or something.
>
> My 3 main at home sings like a harp.
>
> I ran accross the following information, which appears to be a tad
> more definitive than the old clank test.
>
> In WSM 124 "Alpine Series 1 to 4 workshop manual"
> On page 12, under the heading "Crankshaft, Balance"
> The text reads "Integrally forged counterweights"
>
> In WSM 145 "Alpine Series 5 workshop manual"
> On page 17, under the heading "Crankshaft, Balance"
> The text reads "Integrally cast counterweights"
>
> On page 134 of the book "Sunbeam Alpine and Tiger, the
> complete story" by Graham Robson, it is printed that the
> SV crankshaft was "a spheroidal graphite iron cast crankshaft".
>
> Jarrid:
To add to your research, I notice in my 1966 parts manual under 1725
cranks one number is listed as superceded and is followed by another
number and the notation "See Parts Data 2A/299"
"Spheroidal graphite" is another name for "nodular" and is also known as
"ductile iron" The first and second names refer to the internal
structure being characterized by spheres or nodules of graphite rather
than the flakes in grey and white cast. This is a result of special
alloy elements added just before casting and results in improved
strength and ductility.
I have looked at both crankshafts and I agree that the line on the 5
main crank looks far more like a mold parting line than the flash caused
by forging.
Ron Tebo
This archive was generated by hypermail 2b30 : Tue Sep 05 2000 - 09:56:36 CDT