Alfa Pages

[richard33]

I thought that it may be worth passing on a failure mode that I have discovered on some Alfa 33 engines. I have had two bottom end failures on standard 16v engines that I used in race cars. Both engines were original factory built units and failed due to a big end bearing turning in the rod. Both failures appear to have originated from a loosening of a b/e bolt. In both instances I found that the rod in question had misplaced numbering. Clearly, the Alfa factory simply employed a gorilla with a hammer to index the rods and every so often he missed! On the rods that failed, I noticed that the number stencilled on the side of rod assembly partially ran over the interface between the upper and lower parts. This raised a small lip of metal – just where you don’t want it. Subsequent building of the engine then proceeded normally with the bolt being torqued up without any indication of a potential problem,. However, as the engine is run over time, considerable force is repeatedly applied to the interface which brinells the small lip away, so that the bolt torque is lost, and the rod starts to open up and the bearing rotates with catastrophic results.
As a matter of course now, I always look for this aberration and if necessary carefully file away any raised lip caused by clumsy numbering.
Incidently, on stripping a different untouched factory built engine, I found the crank to have three big ends on standard size and one 10 thou under! Fortunately, the bearings fitted were the correct size for each one, but I had to buy second set of bearings to complete the rebuild. I don’t think Quality Control existed in those days.

[johnboy]

Great info , thanks for sharing
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[mg907]

I read several car magazine articles about the weak work organization in the Pomigliano D'Arco Alfa Romeo factory and about the reorganization made by Fiat when they became the factory owner.
It should be interesting to know if the issue you noticed affected even cars build after years 1987/88.