IRS Bearing Housings

[adrian]

Hi All,

I am going through the cert process (down here in nz) with Steve and Adelle Woodbridges old car. The Cert guy has questioned the material in the IRS bearing housing - he believes it is cast - I have tried to find some info on the net on the oe material in the housing, but have come up with zero.

Can anyone on here confirm or deny ? I have the photos from the build that dont look cast but I need some concrete evidence.

Thanks

[dangerous]

If original type 1/3 bearing housings, They are not cast iron.
You can see by the weld, but if need be, spot drill in a safe position and observe the swarf.

If they need concrete evidence, only a spectrometer test on the swarf will give them that,
but any decent guy should be able to see the swarf and determine that it is not cast iron.

[Bruce]

They are steel.  I have MIG welded on hundreds of them including the ones in my own car.  They've had over 150k miles on them since I did them.

Dave's suggestion is also good.  Take a small drill and start drilling.  If you get spirals, you have steel.  If it just crumbles out, it's cast iron.  Also you can do the grinder test.  Steel is yellow sparks, cast iron is orange sparks. Find pieces of scrap of both to try this out.

[adrian]

Thanks for the suggestions. Will get it sorted.

[spanners]

https://www.dropbox.com/s/sjgxm0n98qlbjni/a%20arm%20work%20003.jpg?dl=0
They are a steel forging, here is link to an a arm I am modifying showing the machined and welded bearing housing, like many others, I have been modifying, re positioning, drilling and beating on these with large adjusting hammers for decades, then racing them either off road or on circuit and never seen a failure, the wharmact did the pre production development work for us, failure was not an option.
As an aside, The 'cast' prejudice belongs back in the 19 century anyway, it should be buried together with the 'which oil for my Aircooled VW engine' questions, modern casting methods were developed by wartime German steel industrialist Walter Borbet in the early war years, in short, his advanced casting methods produced the famous 88mm German flack and tank gun barrels in the required wartime number quotas, the power and performance of which earned that fearsome reputation on a well known battle tank, the Borbet name is still synomonous today with modern racing and GP car wheels, most any high performance car engines made today are using cast cranks, Honda compacts have produced 800hp so equipped, casting is no longer the swear word of old with modern materials and pressure/centrifugal casting methods.