Oil scraper rings are spring steel and much easier - a lot less fear of the dreadful snap.

Domed aluminum pistons with two compression and one scraper ring.

The pistons were of aluminium alloy, with three compression rings and one scraper ring.

Gummed-up oil scraper ring and drain holes.

The third ring is an oil scraper ring whose function is helped by the second ring.

Three compression rings, two scraper rings.

Pistons are aluminum domed- head carrying three compression rings and an oil groove in the skirt serving instead of scraper ring.

The pistons were forged from alugir, with three compression and one scraper ring and floating bronze bushes for the gudgeon pins.

The various parts of the strut are sealed with O-rings or similar elastomeric seals, and a scraper ring is used to keep dust and grit adhering to the piston from entering the strut.

Later production R engines featured sodium-filled exhaust valve stems for improved cooling, while additional modifications included a redesigned lower crankcase casting and the introduction of an oil scraper ring below the piston gudgeon pin; a measure that was carried over to the Merlin engine.