What exactly are Wills Rings and how do they work? the picture will explain most of those questions,the words below should tell you the rest of the story.
This is no ordinary Hillman Imp head,its a sport version with its larger valves and ports,plus its been further cleaned up and the ports opened up further too. The black rings are the Wills Rings,they are gas filled tubes which are located in a special groove thats milled into the face of the alloy head,they alone keep the water and gasses seperate.The blue gasket is paper,that keeps the cooling water in its place.
Seen mainly on competition engines due to the cost but only on engines with steel cylinders,that are fitted to 998cc engines and larger,the Wills Rings can not be fitted to a standard 875cc engine,as the pressure of the steel ring will crush the alloy on the top landing of the cast Iorn bore.
This is no ordinary Hillman Imp head,its a sport version with its larger valves and ports,plus its been further cleaned up and the ports opened up further too. The black rings are the Wills Rings,they are gas filled tubes which are located in a special groove thats milled into the face of the alloy head,they alone keep the water and gasses seperate.The blue gasket is paper,that keeps the cooling water in its place.
Seen mainly on competition engines due to the cost but only on engines with steel cylinders,that are fitted to 998cc engines and larger,the Wills Rings can not be fitted to a standard 875cc engine,as the pressure of the steel ring will crush the alloy on the top landing of the cast Iorn bore.