Splitting the single – 1948 EMC 350cc

Bike Profile

1948 EMC 350
1948 EMC 350 Split-single two stroke.

Dr. Joseph Ehrlich, who was born in Vienna and died in Britain in 2003 aged 89, has been described as a “volatile man” and “difficult”, among other things. But there is no disputing that in engineering terms, he was a trail blazer and an innovator who brooked no acceptance of convention. His was a life of experimentation – of challenging the norm.

Dr. Joseph Ehrich.
Dr. Joseph Ehrich.

He fled to Britain where by 1939 he had built a 240cc split single engine, with each 44mm piston running in a 79mm bore. During the war was engaged on several military projects, notably the development of a motorcycle engine which he fitted into an Ariel frame for evaluation by the army. That engine was a two stroke with twin pistons working on an articulated connecting rod. In 1946 Ehrich moved into a tiny factory in Park Royal, Isleworth, London, where he planned to put his motorcycle into production as the 350cc EMC (Ehrlich Motor Company).

The buying public were ambivalent towards two strokes in general, so a twin-piston two stroke was something to be eyed with considerable suspicion in a market where single and twin cylinder overhead valve four strokes reigned supreme. Added to the engine’s quirky specification was its appearance; the massively finned, square barrel and head, with the exhaust pipe emanating from the left side of the barrel, giving the bike an ungainly and slightly unbalanced look. Close inspection of the barrel revealed that the fins were actually of two different sizes – six large fins interspersed with smaller ones. This, Ehrlich explained, was to provided what he referred to as “differential cooling”; to allow the liner to slightly deform or corrugate when it reached operating temperature, and thus retain oil around the pistons.

The rest of the EMC followed normal British practice, with a four-speed Burman C Type gearbox, Dowty Oleomatic (air suspended) telescopic forks and a rather neat double cradle tubular frame with a rigid rear end. The frame was rather unique in that it used a magnesium-bronze steering head and top backbone to which the steel frame tubes were bolted. Ehrich’s own hubs and 7-inch brakes were used; a conventional “cotton reel” with bolted up drum and sprocket on the rear, and a Vincent-style double-sided job on the front. With a retail price of £185, the EMC was only slightly more expensive than the popular 350cc BSA B31.

1948 EMC 350.
1948 EMC 350.

Early versions of the EMC, designated the Mark One, used the antiquated total loss lubrication system with a Pilgrim pump, but this was soon replaced with his own design of reciprocating pump controlled by the throttle. The oil pump was housed in the outer half of the timing chest with two feeds and a plunger to pressure-feed lubricant to the big end bearing. The end of the pump plunger was located in a taper groove machined along the length of a cylindrical slide, with the slide being actuated by cable from the twist grip, matching oil delivery to throttle opening rather than engine speed. To publicise the venture, he also prepared several racing models in 250cc and 350cc sizes which enjoyed reasonable success in Britain, notably in the hands of all-round racer and scrambles star Les Archer who won the very prestigious Hutchison 100 in 1947. By 1948, the racing 350 was pumping out 45hp at 5,500 rpm.

Detail refinements of the road bike were made for 1948. A new frame with plunger rear suspension also differed from the rigid (which was still available) in that the manganese-bronze frame ‘backbone’ was now of forged duralumin. New conical hubs, attractively cast in L33 aluminium alloy with cast-in brake liners and straight-pull spokes, replaced the steel components and by all accounts worked very well. The alloy wheels alone gave a weight saving of 12lb, with the alloy frame section further reducing overall weight. The new model, presumably the Mark Two, was listed with a top speed of 80mph and a retail price of £198 for the plunger (plus the punitive UK Purchase Tax of £57).

Out in the Colonies

Production of the 350cc EMC never reached more than ten motorcycles per week, with Sweden and Australia being the primary export markets. Dean Govan owns two EMCs and has delved in what records exist to compile a local history.

“I first saw an EMC at the Port Pirie Easter speedway in 1948. I had read all about them as my father subscribed to both English magazines, The Motor Cycle and Motor Cycling. My memories of the bike stayed with me, however and I did not see another until in 1999 whilst visiting my friend Peter Allen’s shed I noticed he had a very sad and sorry bike in his collection.

“The bike had been in his collection for many years and he had also collected much literature and information about the bikes. Sven Kallins were the agents in South Australia and I was told that only 7 or eight machines were imported however accurate records were not available and I ultimately located the remains of 10 machines. I was able to contact several people that had owned one at various stages including former employees of Kallins.

Bill Thomas on the EMC
Bill Thomas on the EMC which he rode to equal 1st place in the 1948 Adelaide Advertiser 24 Hour Trial.

“Kallins, as part of the promotion of the make, sponsored Bill Thomas to ride a bike in various trials in 1948, including the Advertiser 24 hour, in which he came equal first. The late Bruce Hector rode one in the Marion Road races in 1948 and at the Flinders Naval Base races in Victoria. Bruce told me that it was a rather disappointing ride as the bike was nowhere as quick as the B.S.A. Bantam that he was also racing.

The two completed EMCs on show in July 2001.

“I had collected enough components to complete up to four bikes and did complete two, with one bike being used quite a lot. I found it a very torquey bike to ride, really only needing top gear, it could be started off in top and pull away without a care. I subsequently put together 2 bikes, SA 12041 and SA 99611 and 75% completed SA 93001. SA 99611 came home early in 2000, it had no oil pump, rear wheel, headlight, magneto, carburettor or gearbox and had a cracked frame. 12041, which was the bike Peter had, arrived soon after minus a carby and with a broken frame, with a rear wheel for 99611 and another motor. Subsequently I acquired 4 further motors, two frames and other sundry parts that assisted in me completing two bikes. I repaired the frames, fitted springs to the forks, made the stands, mudguard fittings, found headlights, footrests, levers and other sundry parts. They were not intended to be restorations as such; the project was to complete two running rideable bikes.

EMC Amal Carburettor
Horizontal Amal 1 1/8” carb supplies the mixture.

“The engines, being two strokes rely upon crankcase compression, and one of the faults of the design was the manner in which the crankshaft was sealed. On both sides there was a series of plates with felt seals in between. These had been one of the design faults so I replaced the bearings on both sides with sealed bearings and they worked satisfactorily. Another fault was the design of the pistons; they were about 90mm long and the gudgeon pin was about 30mm from the bottom. Every piston in all the engines that I had showed signs of being severely seized at some time. In building the engines I picked the best parts from whatever I had. I had new gudgeon pins and piston rings made. They are fitted with Pilgrim double acting oil pumps and they had to be “timed” so that the correct amount of oil was delivered to the big end and the rear cylinder, and that proved a complicated process. The first one – 12041 – was completed and ridden in October 2000. It was a pleasant torquey bike to ride however it did not live up to all the claims Dr Joe made when first announced. The bike was registered and ridden by myself and Peter many times over the following year. 99611 was completed by July 2001. It seemed to be a better bike than the first one however it has not been used since completion. 93001 was about 75% completed and is somewhere in the Birdwood Mill Museum from where some of the parts came from.”

Completed EMCs 2001.
August 2001, and Dean Govan now has two completed bikes.
1948 EMC 350
1948 EMC 350 Split-single two stroke.

In NSW, Greg Freeman owns a 1948 EMC, one of the very few ‘late models’ to come to Australia. This motorcycle was purchased new by Greg’s grandfather, Bob Jones, who will be familiar to a generation of dirt track riders who raced at the still-operating Nepean Speedway – the only remaining dirt track in Sydney. Bob was ‘the man’ at Nepean, living on site in a very basic shack, operating the equipment that kept the track in top condition, building fences – you name it.

Bob’s EMC was used for everything from daily commuting to various forms of competition – reliability trials, observed trials, scrambles and Short Circuit racing. In Greg’s hands, it has even appeared in Historic Road Racing. As it is substantially complete and original, Greg has no plans to restore the EMC. It has the standard fitment 20-inch front wheel with 19-inch rear, a Lucas TT magneto and Amal 29-Type carburettor.

Specifications: 1948 EMC 350

Engine: Split-single two stroke
Bore x stroke: two cylinders 50mm x 88mm
Capacity: 346cc
Compression Ratio: 7.6:1
Carburettor: Amal 1 1/8”.
Power: 18hp at 4,000 rpm
Transmission: Burman 4-speed gearbox with oil bath primary chain.
Suspension: Front: Dowty Oleomatic forks, Rear: Plunger or Rigid.
Frame: Double cradle, electrically welded, with cast top section.
Tyres: Front 3.00 x 20”, Rear: 3.25 x 19”
Petrol tank capacity: 3 gallons.
Ignition: Flange-mounted BTH ‘TT” magneto.
Electics: Lucas dynamo.
Colours: Maroon or Black

This article first appeared in Old Bike Australasia Issue 49.