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Weight comparison between the previous and new exhaust systems for the 11BV model, with a proposal for further weight reduction.


Identifier  ExFiles\Box 99\1\  scan0187
Date  9th May 1940
  
Rm. {William Robotham - Chief Engineer}
423
1115

Rm {William Robotham - Chief Engineer} /WYM. {G. Harold Whyman - Experimental Manager} 7/JM. {Mr Morley} 9.5.40.

EXHAUST SYSTEM WEIGHTS.

PREVIOUS SYSTEM ON 11BV.
DOWNTAKES. S/M.
10'10" in 12.SWG.=25lbs 8ozs.
FRONT BOXES. (including inter pipes)
STAYBRITE.
With inter pipes 3' in 12.SWG= 32lbs 0ozs.
REAR BOXES S/M STANDARD.
=17lbs 8ozs.
TAIL PIPES. S/M.
11" in 16.SWG 1 1/2 dia.
= 15lbs 0ozs.
TAILPIPE EXTENSIONS.
Chromium plated = 2lbs 0ozs.
TOTAL WEIGHT.
= 92lbs 0ozs.

NEW SYSTEM ON 11BV.
DOWNTAKES. S/M.
10'10" in 16.SWG.=16lbs 5ozs.
FRONT BOXES. (including inter pipes)
STAYBRITE.
With inter pipes 3' in 16.SWG= 28lbs 11ozs.
REAR BOXES S/M SHORT TYPE.
=12lbs 10ozs.
TAIL PIPES. S/M.
11" in 17.SWG 1 1/2 dia.
= 12lbs 8ozs.
TAIL PIPE EXTENSIONS.
Chromium plated = 2lbs 0ozs.
TOTAL WEIGHT.
= 72lbs 2ozs.

The exhaust system as erected on 11BV car, has 14 flanges and 28 bolts, nuts and washers, weighing 4 lbs 6 ozs, excluding the 2 flanges and bolts etc. necessary for bolting the system to the manifolds.

We consider that 4 flanges are necessary to connect the tail pipes to the rear boxes, but 10 flanges could be dispensed with if the whole exhaust system was slung under the frame with a further saving in weight of 3 lbs 2 ozs, bringing the weight of the system down to 69 lbs.

Rm {William Robotham - Chief Engineer} /WYM. {G. Harold Whyman - Experimental Manager}
  
  
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).


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