An interesting bit of CSL trivia nobody knows about (?)

[roundel]

An interesting bit of trivia that will have you all under your cars checking your engine blocks this weekend........
What BMW wanted to Homologate another version of the M30 block for their race CSLs in 1973, without water channels between the cylinder bores in order to be able to increase the bore size to 94mm and achieve a capacity of 3.5 litres. The rule of the FIA stated they had to fit this into a certain amount of production cars sold to the public.......the casting number on the block was changed so they could be identified.
So if you have an E9 or E3 built in 1973 it is possible your car has one of these engine blocks. They will have a casting date of 1973 and the last three digits of the casting number would be `466`. If you have one of these you are lucky, but don`t get too excited. This was all a con...the blocks fitted to production cars were just normal blocks with a `466` casting number.
So far I have found them in a 3.0 Si sold new to Australia, and a series one Batmobile.

Good Luck.....

 

[Stevehose]

Interesting. So they all were cast with 466 then the CSL ones were then machined separately?

 

[roundel]

The Motorsport blocks were a different casting, the ones put in street cars were a standard casting with the Motorsport casting number on them....

 

[rsporsche]

i wonder if this would be more applicable for the CSi / Si cars than the base CS cars as i would assume the engine production would have only been the higher compression engines.

 

[roundel]

As the block was the same for carbs or injected it could be either....but only 3.0 litre cars.... However the two blocks I have found come from injected cars....

BMW must have had a way of tracing the cars you would think...in case they had to prove these engines existed....??