‘The Roaring Raindrop’- MG EX181…

Posted: February 26, 2020 in Who,What,Where & When...?
Tags: , , , ,

(Theo Page)

Perhaps MG saved the best till last?

EX181 was the marque’s final record breaker, which commenced with the 1930/1 EX120…

The famous company, in part built its brand very cost effectively by setting a number of Land Speed Records down the decades. Stirling Moss did 245.64 mph and 245.11 mph for the flying kilometre and flying mile respectively in August 1957, and Phil Hill 254.91 mph and 254.53 mph over the same distances in October 1959 with EX181’s engine increased in capacity from 1489cc to 1506cc- this allowed the sneaky Brits to bag both under 1500cc and under 2000cc records, both at Bonneville.

Twin inlets in the cars nose pushed air thru ducts either side of the driver and flow to the radiators, carb inlets, the engine and transmission- outlet ducts clear (unattributed)

The Roaring Raindrop was not just a teardrop shape known to give minimum aerodynamic drag at subsonic speeds- in side elevation it also had the cross section of an aerofoil to a wing section of Polish origin which was identified by MG Chief Engineer Syd Enever as ideal for the task. His theory was tested by Harry Herring in the Armstrong Whitworth wind tunnel.

The Morris Engines Experimental Department in Coventry developed an MGA twin-cam, two valve engine which had many trick lightweight competition internals ‘off the shelf’ and a massive Shorrock supercharger driven by a spur gear from the front of an extended crankshaft fed by two whopper 2.5 inch SU carbs. The fuel mix was one third each petrol, benzol and methanol.

The 1957 1489cc engine developed 290 bhp @ 7300 rpm and 516 lb/ft of torque @ 5600 rpm using 32 psi of boost. Cooling of the motor was achieved by the use of two curved radiators from an Avro Shackleton marine reconnaissance aircraft.

(mgaguru)

 

(mgaguru)

EX181 was built under the supervision of Terry Mitchell using a bespoke twin-tube chassis with MGA derived suspension at the front- wishbones, coil springs and lever arm hydraulic shocks and a de Dion rear setup deploying quarter elliptic leaf springs and again lever arm shocks.

Cooling for the single Girling disc brake was provided by a small hinged rear flap on the central spine of the machine aft of the cockpit, this popped  up when the driver pushed the brake pedal and also acted as an air brake.

The final essential element in the cars record breaking specification was Dunlop 24 inch diameter tyres capable of inflation to in excess of 100 psi.

Snug in there, Moss Bonneville 1957

Etcetera…

(S Dalton Collection)

Credits..

Autocar, Theo Page, MotorSport article August 2008, mgaguru.com, Stephen Dalton Collection

Tailpiece: Phil Hill, EX181 Bonneville, 1959…

(unattributed)

Finito…

 

Comments
  1. David E.M. Thompson says:

    I saw this in MGA ads from my earliest experience with sports cars. But only the ads. This fills in lots of blanks. Thank you.

  2. Gerry LaRue says:

    No disrespect to Syd Enever but the wing shape seems upside down to me. The longer length path on top of the body relative to the roughly flat underside should mean the air flowing over the top would have a higher velocity and therefore lower static pressure than the flow underneath. Generating lift then rather than downforce.
    Not the only example of this shape in that era of land speed cars so maybe I am missing something.
    It was a wonderful looking design and a significant speed from such small displacement and the technology of the time (and very brave drivers).

    • RG says:

      I wonder if they were even trying to create downforce. That was a pretty novel concept at the time. My assumption has always been they were looking for minimum drag. Period.

      To me, the genius of Enever was the fact it took Government Motors 30 odd years, and a very large pile of cash, to take those records away from MG.

      • markbisset says:

        RG,
        LOL luvvit re Government Motors- as i just mentioned in the response to Gerry, i’ll have a bit more of a poke around, not that my own library is ‘MG Strong’!
        Mark

    • markbisset says:

      Cheers Gerry,
      I’m afraid my humanities brain gets in the way of understanding many things not least aerodynamics. If i get the chance i’ll have a bit more of a fossick into the car, especially its aero properties.
      Mark

  3. RichardF says:

    Pretty impressive that in 1957, MG’s ‘Skunk Works’ could squeeze 290 bhp and 516 lb/ft from 1489 cc’s, albeit from a short-life engine, via the brute force of 32 psi boost, and the only standard production item (perhaps) the cylinder block.

    And such a shame that meanwhile, on the production MGA Twin Cam, they never solved the piston burning problem, that killed that model, and was later traced to just a carburettor vibration, which was easily resolvable with flexible mounts.

    • markbisset says:

      Cheers Richard,
      Yes, no doubt the engine life was very short. Interesting your comments on the production Twin-Cam, I was aware as someone not knowing much about the cars that their was an engine reliability issue but didn’t realise the fix was so simple- doubtless the process of diagnosis was not!
      Mark

  4. Walker Love says:

    This was an amazing accomplishment for 1957, but believe it or not, the 1500 cc record still stands more than 60 years later!
    How about them apples.

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