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soft metal ( crank )
seagull - January 23rd, 2004 at 08:54 PM

I have just cut a 1600cc crank in the band saw ,I was very suprised how soft the steel was it cut like butter ,no wonder they snap off so well !

Craig Torrens - January 23rd, 2004 at 10:17 PM

was it a german crank or one of the later cast brazilian ?

seagull - January 24th, 2004 at 01:00 AM

The od of the crank was tuff ( bearing service ) this had been done by flame torch in the factory, 3mm in was this way after this the steel mach like 4140 grade I was suprised of the quality .

vw54 - January 24th, 2004 at 06:19 AM

Thats how a crankshaft is suposed to be. there only ever hardened on the bearing journals.

They need a certain amount of flexability and or twist built into them.

Its the grain structure of the metal and its alignment thats the all important factor.

If you were trying to harden the inner structure of a crankshaft , you couldnt quench it quick enough after heating to convert the grain structure. Its just too thick through the center section to do this and if it was hard the crank would fracture easier.

56astro - January 24th, 2004 at 07:52 AM

Quote:
Originally posted by vw54

They need a certain amount of flexability and or twist built into them.




:o

Fair dinkum?

seagull - January 24th, 2004 at 05:37 PM

Has some one got a snaped unit they can show and tell !

Craig Torrens - January 24th, 2004 at 06:03 PM

maybe if I had a SCAT crank I could show you.;)

seagull - January 24th, 2004 at 11:17 PM

:beer

Craig Torrens - January 24th, 2004 at 11:28 PM

haven't you seen the pictures on the USA web sites. There's some good ones, one crank is in three pieces !

I love seeing carnage !

Can you cut a crank down the middle length ways? make a good paper weight !

seagull - January 25th, 2004 at 01:13 AM

race car 5ltr with a snaped crank $$$$$ and it did 500mtrs from new :alien

In the next few days photo