Rolls-Royce 20/25 - block & tappets



block off



After removing the tappet bridge pieces it is a simple matter of lifting off the cylinder block. In this case it slid off without the slightest resistance - probably helped by the amount of oil that has leaked out of the bottom gasket over the years.




After removing the bridge pieces the block will lift off. If the upper tappet spring retaining collars are loose in the block they should be removed, along with the spring and push rod cup, before lifting the block.

tappet removal



A complete tappet assembly being lifted out. Note that the hole in the crankcase face has 4 slots cut into it. The cam follower wheel, at the base of the tappet, is aligned across the engine.

teppet assembly



Spot the deliberate mistake.

This is number 4 tappet, which has a broken spring, which accounts for the clicking noise that has been evident for the last few years.


main bearing studs



The main bearing studs pass through the crankcase casting and are located beneath the cylinder block. The studs are screwed into a cylindrical head, are cross-pinned and retained in specially shaped rebates. They are loose enough to drop out if the engine is inverted at this stage.