Rolls-Royce Phantom III - oil level gauge & pressure relief valve


Next page
Go find


R-R PIII - dirty oil level gauge Rear view of the oil level gauge;  still working despite a generous covering of gloop.  The pipe feeding into the top is the return pipe for any liquid oil collected in the crankcase breather.  This pipe was still open but, unfortunately, the breather outlet was completely blocked with oil sludge.
R-R PIII - oil level gauge parts The components - delightfully simple and beautifully made.  The drain tap is a tapered brass plug with a cross drilling.  The black spring ensures that the drain plug does not leak when closed.
R-R PIII - rebuilt oil level gauge Back in one piece and showing 'MAX' as the unit is resting on the float.  The drain plug leaver required straightening due to a gorilla's touch some time in the past.  It is important to make sure that the spring-loaded retaining catch (in front of the 'SHUT' lever) is free to spring in and out.
R-R PIII - oil pressure relief valve components

The oil pressure relief valve in bits.  The high pressure relief valve is on the left and is set to lift at 15psi.  Centre is the low pressure valve, also set to lift at 15psi, which is in a common chamber with the rocker outlet on the right.  (NOTE the ball bearing non-return valve which is not shown in the drawings.)  The effect of the two valves is to feed the crankshaft at 25-35psi and the rockers at 15psi.

Various factory modifications were made to overcome operating problems encountered in service; the majority being due to the poor quality of oil available at the time.  These solutions created further malfunctions that were, in turn, rectified with unsatisfactory results.  I have returned the springs back to original settings (supplied by the PIIITS) with satisfactory pressure results.  As the valve mechanism has also received the secondary modifications I will monitor the eventual performance, on a clean engine, with interest.  The oil holes in the two banjo screws on the tappet filter have been enlarged to the original dimensions in order to return the rocker oil flows to original specification.  Valve seals have also been replaced with Teflon chord.

R-R PIII - oil pressure relief valve The cleaned item.  Oil inlet, at the left, from the pressure filter.  The small outlet at the base is for the oil pressure gauge in the dashboard.
R-R PIII - oil filter pipes The left hand pipe connects the top of the pressure filter to the inlet of the pressure relief valve.  The right hand pipe connects the oil pump to the bottom (inlet) of the pressure filter.  Yet another example of the idiot's charter to car maintenance.  This will require replacing before the engine runs.
R-R PIII - sump oil filler pipe The oil filler pipe deeply pitted from years of water leaking from the cracked block - obviously before the 'temporary repair' was effected.  I have just cleaned this and painted the corroded area to stop further degradation.
R-R PIII - oil filler pipe lid The lid, right, shown partially dismantled.  The spring loaded plate, still in the lid, was not removed as it is riveted and I did not want to risk permanent damage.  Everything was cleaned thoroughly and re-assembled.  The holes in the leather seal are copper grommets.
Back to the diary.
Go find
Next page