There have been reports of Mini's being fitted with C-shape counterbalance webed crankshafts.
These are not permitted as there has been no evidence that they have been used in period.
The following is the wording regarding period parts taken from the 2017 Blue Book.
Please supply documented evidence as per Article 49.6 page 329 of the 2017 Blue Book .
Only period modifications used in rallying on the particular make and model of car are permitted for Category 1,2,3 and 4 rally cars.
As always, if evidence is produced then the fitment of this type of crankshaft will be re-considered.