Rolls-Royce Archives
         « Prev  Box Series  Next »        

From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Report discussing design considerations for engine valves and ports, including temperature, shape, and cooling.

Identifier  ExFiles\Box 134\2\  scan0166
Date  16th October 1937
  
-4-

(7) Exhaust Valve Temperature - Cont'd.{John DeLooze - Company Secretary}

A point about the valve arrangement which was stressed by Bertelli, is the great advantages you can get in the way of exhaust valve cooling, even while sticking to vertical valves. It will be quite obvious, as is shown in the sketch, that ample water space can be allowed right round the valve, and it is claimed that where with the old arrangement a cooled valve was necessary, with this new scheme, coupled with the increased length of valve guide possible in the port shape used, a solid valve could be used quite comfortably.

(8) Port Shapes.

It will be noted that Fig. 1 shows square ports, and these are used as they enable a greater port area to be got in approximately the same space, and are therefore a very economical shape.

Venturi ports were used, and Bertelli showed us the one sketched in Fig. 2 as being a comparatively recent development of Ricardo's, and claimed by them to give a very good performance. He could give no figures, however, and was himself rather sceptical.

Coventry Climax stated that they had tried Venturi ports and could get nothing from them.

(9) Valve Shapes.

With regard to valve head forms, shapes similar to those in a previous report of a visit to Ricardo were confirmed as being satisfactory, i.e. the tulip type of valve for exhaust, and a flat valve with a domed head for the inlet. This confirms results we have done ourselves in which a flat inlet valve gave superior power to a tulip type. It did not have the strength given by the domed head, however, and suffered from cracking.

This summarises most of the information obtained.

Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards}
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙