Rolls-Royce Archives
         « Prev  Box Series  Next »        

Acceleration and expanding carburettor tests at Brooklands.


Identifier  ExFiles\Box 13\4\  04-page001
Date  13th July 1932
  
X7080 Morning.
Copy for Brooklands File.
X788

13.7.32.

22-EX.
Acceleration tests carried out with 7 x 20 tyres fitted, over the half mile, with these tyres on, cut-out closed.
At Brooklands.

7 x 20" tyres. Lap speed Air Temp. 22.5°C.
over 1/2 mile 21.4 secs 81.62 M.P.H.

Expanding Carb.

Cut-out closed Lap. 119 secs 83.70 M.P.H.
" Open Lap. 113 " 88.15 M.P.H.
"Repeat" Cut Out open. Lap. 112.5 secs 88.54 M.P.H.

Cut-out Closed 1/2 mile - 21 secs. 85.71 M.P.H.
Cut-out Open 1/2 mile - 19.8 " 90.91 M.P.H.
"Repeat" Cut-out Open 1/2 mile - 20 secs 90.00 M.P.H.

With air-piston removed as Rn. {Mr Robinson} instructed:
Jet held in position in centre of cock.
Position:- 1 1/4" above face of carb. - Swindall know's where this position is exactly.

Series of tests - with piston out of carb - 1 1/4" from face.
Lap Speed C.O. - 111 secs 89.74 M.P.H.
1/2 mile C.O. - 19.5 " 92.31 M.P.H.

"Best Position" }
with piston } piston out of car 1 1/4" from face.
removed. }
Lap Speed C.O. 109.8 secs 90.72 M.P.H.
1/2 mile C.O. 19.2 " 93.75 M.P.H.

piston out of carb 1 3/8" from face.

Lap Speed C.O. 110.4 secs 90.22 M.P.H.
1/2 mile C.O. 19.5 secs 92.31 M.P.H.

"Best Position" }
with piston } piston out of carb - 1 1/2" from face.
removed. }
Lap Speed Cut-out closed 116.4 secs 85.57 M.P.H.
1/2 mile " " 20.5 secs 87.80 M.P.H.

Acceleration tests :-
10-20 4.7 secs 40-50 6.35 secs
with 7 x 20 tyres
20-30 5.2 " 50-60 7.00 secs
(average of two track)
30-40 4.9 " 60-70 9.5 secs.
positions.
  
  
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).


Copyright Sustain 2026, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙