Maybe this is the reason Lampredi design features are not used in current engines such as Honda or Mercedes Benz and the reason Ferrari had the most success with the Colombo designed engines. The V-12 Lampredi engine has cylinders that thread up into the cylinder head instead of pressed into the block, but the camshaft and valve actuation are similar to the Colombo designs.
The block of this 4 cylinder Lampredi engine is actually the head, a huge casting with enormous cylinders that thread into it like the V-12′s. The valve actuation is a different style with a huge aluminum followers and a roller of the same size as the V-12 engines. There are huge and very strong “hairpin” style valve springs and enormous coil springs to keep the aluminum followers from floating.

Ferrari 750

Cam Follower Ferrari 4 cylinder

Roller followers Needle Bearing

Ferrari Camshaft wear repair
Due to lack of Ferrari Factory testing in the mid 50′s, they didn’t observe that this is just too much spring pressure for the roller follower to handle so after less than 2000 miles something gives up, be it the roller follower or the camshaft… and in these photos you can see what happens. The tiny needle bearings come apart and scatter in the engine and the cam is torn up. Maybe the load is too much for the roller follower and it blows apart or the camshaft gets worn and hammers the roller follower until it deteriorates?