Rolls-Royce 20/25 - pressure testing the crankshaft



blanking crank


The oiling holes in the crankshaft nose were blanked off using leathercloth and Jubilee clips.

pressure tank


A pressurising system was rigged up using a modified garden spray, the standard oil supply pipe and a spare oil pressure gauge.

An interesting point of note is that the crankshaft and oil supply pipes contain about 3 pints of oil.



The system was sealed, pressurised to 20psi and left for inspection.  The crankshaft was slowly rotated to allow oil to bleed from each set of big end bearings.

When these engines are running at the correct temperature the oil pressure should read 18psi.



All good news!

Oil eventually started to leach from each of the main and big end bearings.

No oil was seen weeping from any of the unwanted sources: -

  • the supply pipe joints were dry
  • the soldered joints on the oil gallery pipe were dry
  • the cylindrical plugs in the cast webs were dry - even where they had been leaking prior to treatment
  • the sludge traps were dry

All in all a most satisfactory result.