Sunbeam Thirty




The first Rootes Sunbeam was designed by Georges Roesch as Rootes’ flagship. A new 4503cc straight eight engine was designed for the Thirty. It developed 150bhp @ 4500rpm. A four speed gearbox was fitted, without syncromesh on first.

The chassis was based on that of the large Humbers of the period.

It appeared at the Olympia Motor Show in 1936. It was then decided not to put the Thirty into production. The four cars built were all broken up.

4 thoughts on “Sunbeam Thirty”

  1. The car shown above was the Sunbeam Thirty Continental Phateon. It was certainly not broken up, it was converted to Humber Imperial Cabrio and i am the proud possesor of the car !! It was delivered to Mr V.P. Mobbs, the original purchaser whose name appears on the handwritten records of Thrupp & Mabberley. I am currently having the car fully restored and the interior and hood are nearly completed.
    The car i have is certrified in writing by the Science Museum in London as being the same car converted from Sunbeam to Humber by Thrupp,s Photos and all 1936 Motor Show erecords are all in my possesion.
    Any informatioon would be greatly appreciated,

    Archie Marshall
    Perth Australia.

    1. I am interested in learning certain details about the engine of the Sunbeam Thirty. In particular, can you advise the following?

      Bore & Stroke
      Number of main bearings
      No. of valves per cylinder
      No. of spark plugs per cylinder
      No. of carburettors
      Configuration of block, I presume it was a monobloc casting?

      many thanks

  2. The engine fitted to the car on being converted by Rootes is the stasndard Humber Side Valve 6 cyl engine.
    I imagine you want to know the detasils of the original Sunbeam Thirty engine which was an 8cyl OHV engine?
    I can look up that information or i can copy the original documents and send to you ?
    please advise,
    Archie W. Marshall

    1. I am ther owner of the Sunbeam Thirty 1936 which was converted to Humber Imperial by Rootes following the abdication of King Edward V111. The car is now restored and won the W.A. Vcc car of the year award in 2005. I have all the documents proving all the history etc and would be glad to share with anyone interested. Regards to all, Archie

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