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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).
Proposal for a standardized cooling system test to gather comparative data on the 40/50 HP and 20 HP models.

Identifier  ExFiles\Box 24\4\  Scan079
Date  1st August 1923
  
X766

To Hs.{Lord Ernest Hives - Chair} from Da{Bernard Day - Chassis Design}/Ev.{Ivan Evernden - coachwork}
c. to CJ. BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer}

Da{Bernard Day - Chassis Design}/EV{Ivan Evernden - coachwork}1/M16. 8.23.
X766
X.488
X.1751.

RE. 40/50 & 20 HP. COOLING.

With a view to future design and improvements in car cooling we have made some comparative investigations and Mr. R.{Sir Henry Royce} would like you to obtain for us the following comparative data between the 40/50 and 20 HP.

We wish both cars to be run under their worst conditions for cooling, i.e., climbing their maximum gradient on top gear at full throttle. From your Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}/LG21.6.23., this appears to be :-

CAR. WEIGHT. AXLE. GRADIENT. M.P.H. REVS.
40/50 55 cwts. 15 x 52 1 in 14. 21 750
20 HP. 39 cwts. 12 x 50 1 in 17.6 17 750

As far as we can see from the chart of M.E.P's with your Hs{Lord Ernest Hives - Chair}3/LG11.5.23., in each case the revs. would be about 750 per minute.

The cars would be tested as follows :-

(1) Radiator filled full.
(2) Warm to 80°C. and note the amount lost due to real expansion prior to steam expulsion.
(3) Car put on hill, all out.
(4) Note amount of water expelled before nothing but pure steam alone is emitted from the steam pipe.
(5) Car run for say an hour (equivalent to an Alpine Pass of say about 20 miles long), and note further loss.

These results can be plotted on graph, thus :-

(see original for sketch.)

We wish this to be a standard type of test for cooling and would like you to try it for :-

contd,
  
  


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