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).
Vehicle cooling system efficiency, comparing fan and radiator performance.

Identifier  ExFiles\Box 22\1\  Scan214
Date  25th November 1924
  
R.R. 493A (20H) (D.A. 652 20-5-24) J.R.D.

-5-
Expl. No.

REF: Hs{Lord Ernest Hives - Chair}/Bm/LG25.11.24.

EXPERIMENTAL REPORT.

40/50 is enormously dependent upon its Fan. When the RR. fan is removed, the efficiency of the system drops 30 %. The Hispano, on the other hand, under similar circumstances, only drops 10%.

EAC.11. Radiator Tubes.

Shortening the radiator tubes from the std. length of 4.8" to 4.4" reduces the efficiency of any given size of matrix by about 4% at 30 m.p.h.

Painting the matrix face.

We could detect no difference between the performance of painted and unpainted matrices.

Present limit of improvement of 40/50 HP.

By fitting the 22" matrix and 8" X 14" shutters, the efficiency of the 40/50 HP. cooling system can be brought within 2% of that of the Hispano at 30 m.p.h. This means that under these circumstances the critical temperature of the latter will only just be over one degree more than that of the RR. At 20 m.p.h. however, the discrepancy between the two cars increases, as the RR. system cannot deal with the heat given to the cooling water so well at this speed.

In all cases, unless the RR. fan is functioning satisfactorily, over-heating is liable to occur under quite normal atmospheric conditions.

contd :-
  
  


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