The initial development of the k series into Caterham required a north / south installation as opposed to the east west. The other major issue was the height of the engine the bonnet line had to remain undisturbed . The installation was 12deg as per Rover installation. This in turn effected the design of the sump. The standard sump not being an option. During the development phase engine failures occurred, examination revealed valve failure due to oil airation. The baffle was modified and foam added to reduce the suspension of air in the oil. ( the air is purged from the oil when the airated oil contacts an object). This resolved the issue. It appears the cause of failure of the foam can be down to :- A) Foam - original quality , specification, age, contamination, batches, shelf life, stock rotation, supplier. B) Degradation due to oil, coolant, fuel. C) Working inviroment. My moneys on A. The foam fitted to my car was from 1996 .