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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).
Letter from Alta Car & Engineering Co. Ltd. detailing performance tests of RR 56 connecting rods in their racing cars at Brooklands.

Identifier  ExFiles\Box 27\2\  Scan219
Date  31th May 1934
  
TELEPHONE—ELMBRIDGE 3157
TELEGRAMS—ELMBRIDGE 3157

ALTA CAR & ENGINEERING CO. LTD.

Directors —
C. TAYLOR
L. TAYLOR.

May 31st, 1934.

FULLER'S WAY,
KINGSTON BYE-PASS,
SURBITON.

Your Ref. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}14/KW.
Our Ref. GT.LV.

Messrs. Rolls-Royce Limited,
Derby.

Dear Sirs,

For the attention of Mr. Robotham.
==============================

Further to our correspondence on the use of RR 56 connecting rods on the ALTA racing cars; we have now carried out a few tests during races at Brooklands, one of which was won by us at a record speed, of the RR 56 rods exactly as previously fitted but lined by the Glacier Metal Co. with .015" of white metal.

You suggested that continuity of oil feed was probably our previous trouble and we went through the system very care-fully but could not find anything that appeared to be wrong and we therefore decided not to modify anything except the rods.

The rods were finished witha a diamond tool and were not hand fitted in any way and ran with a clearance of .0012", there was no time to give them more than an hour's running in before the races, during the races the engine reached a maximum of 6500 on top gear at full blower pressure. Upon stripping down afterwards the rods showed a good bearing with no sign of heat or metallic contact which rather points to the fact that the RR 56 run direct on Nitralloy has not such a good load capacity as white metal, this is rather borne out by the fact that on the unsupercharged car RR 56 is perfectly satisfactory. We intend using white metal in future on account of the small chance of serious damage if a big end gives trouble.

We think perhaps the above details will be of use to you.

Yours faithfully,

ALTA CAR & ENG CO. LTD
G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Taylor.
DIRECTOR
  
  


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