Peter Hubbard Berkeley

August, 2008





13th October 2004

During the 4-year restoration of UBM 114, a SE328 4 wheeler but with a 492cc 3 cylinder Excelsior engine, my mind wandered to my earlier life in the 60ís when for 10 years I raced Class 4 go-karts, quite successfully.

If only the Excelsior had more power, I could use it for competitions since its quite like a Formulae 1 go-kart.

So I went and purchased a second 4 wheeler and located the Rotax Company in Austria who produced modern water cooled 493cc twin cylinder 2 stroke engines. These were fitted with reed valve inlets, RAVE exhausts (the exhaust port is automatically increased in height as engine speed increases) and 2 massive Mikuni 38mm carbs. Output is about 90 hp at 8500 rpm.  Oil injection direct into crankshaft bearings and cylinder bores. Electric start via a specially made crankshaft pulley/flywheel. All these parts were put into store for my retirement in 2004 and some time to put it together.

Anyhow I completed the SE328 restoration but had great problems with the SIBA unit starting when hot. After the 5th engine removal to try to sort the problem, I caught site of the Rotax engine and of course slung the Excelsior under the bench and proceeded to fit the Rotax. This was 2002.

After extensively modifying and strengthening the transmission, fitting a Norton clutch and primary belt drive system, upgrading to VRA gearbox, fitting a radiator from a Kawasaki bike, electronic rev counter I ended up with car which Berkeley would build today if still alive.

All the changes were made without any bodywork modifications, I ended with 1/8 inch clearance between top of spark plugs and the bonnet. It took me 3 months to cut and weld the expansion chamber which is also thermally insulated to keep the heat away from the engine area.


Initial runs on my local roads showed great potential but the 1st competitive event, a sprint meeting at Goodwood in September 2004 ended about 100 yards from start line with the electric starter gear ring coming adrift.

So September 11/12th 2004 I managed to get an entry, really like henís teeth, at Shelesley Walsh. Its been a hill climb for 100 years and is seen as the pinnacle of the sport. August 12th  1905 meeting was won by a Daimler 35hp with time of 77.6 seconds. Today the record is down to 24 secs!!!.

Anyway I managed 54 secs. Beating a 998cc Mini Cooper but I was suffering pre-ignition giving great problems getting away on the line and incorrect gear ratios, only used 1st and 2nd. Into 3rd and it died on the incline (1 in 8) to the finish line. My top speed was theoretically 138 mph on a flat straight!!

So the winter to sort out problems, some re-gearing down to 98 mph top and I can see 44 secs next year at Shelesley.

According to their records, the first Berkeley to ascend the Shelesley hill.

I must say I am amazed at the interest the Berk caused at both Goodwood and Shelesley. At times there were 20 people peering into the engine compartment, most of them past Berk owners now driving Ferraris, Lotus F1, etc.

Peter Hubbard.



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