Sunbeam Alpine: Pressure Relief Valve PRV Comparison and modification

Rootes fitted numerous different pressure relief valves (PRVs) to the engines and low oil pressure has always been an achilles heel of this design. Modifications such as this one are not new, they were recommended in the very first publication of 'The Alpine Guide'. This video shows how we do this and have done so since the 1980s. It is a simple method that works but requires scrupulous cleanliness.