()then, ise. the IAN l’ design was hillom,ed, tin. combustion chamber layout of Nyhieh had far exceeded expectations. %slide I he sump was
already of light alloy, although it was made slidttly la 101 Hie Siang l’ar yen:inn, and the oil-pump capacity was increased by 50 per cent.. a float-type oil filter being provided for the wimp and the sump suitably baffled to obviate surge of the lubricant. Naturally, a flywheel had to he provided 1.41 aeeommodate a Borg and Beck elutelt and a starter ring, and provision was made for ;1 .•ooling fan if’ required. ss Idle the cylinder-head rusting Was slightly altered so that a dynamo could Ii,’ mounted. After much experiment at ion. I win I .’,..in, sem doss ildratiglit I….I_ car
buretters were adopted mid there wms the I’M sports-car engine. .ehiell proceeded to win races :limosi from itincept ion.
As a mailer of fact. Mundy at first developed it as a 1,020-c.c.
Unit with the e.i. crankshaft and, in V, II . formic, h, hp. was developed at 6,000 r.p.m. The comprcs!-Mil-ratio of the subsequent 1,097-c—version was raised from 7.4 to I to 8.8 to I for the. 1954 prototype, and last year is as increased to 9.8 to I for the production engines. This EWA engine has the useful and endearing characteristic of improving its power output with use, but the official figure is
75 b.h.p. at 6,100 using Clevecol petrol. Champion N A10 plugs and with dynamo, water pump and Burgess silencer in situ. The dry weight. of’ the engine is 215 lb., complete with carburetters. distributor, single front and rear mounting plates: A piston speed of 2,500 ft. per minute is reached at 5.730 r.p.m. Incidentally, the main bearings arc 24 in. dia. by 1 in. wide leadbronze steel-baeked thin strip type, aml the hig-ends are of the
same type, measuring in. by ‘4 in.: the valves are of X 13 steel. seating in shrunk-in Austcnitie rings in the alloy head. The top piston rings are chromium plated and easily renewable slip-fit dry liners are used in the alloy cylinder block. An oil-cooler can he fitted if required. Tappet adjustment is by packing shims within the piston:tappets, a set of extra shims being carried in the camshaft vover for resetting the tappets correctly after valve-grinding.
A first batch of [26 [‘WA engines WWI laid down, of’ which 90 have Imen delivered, notably to Lotus Engineering, Cooper Cars. Kieft and others. Amongst eXinn-t s, two have already gone t.ci Australia and others to America a nd Canada. These engines are made mainly for itrestige, rather than commercial purposes, for the makers sensibly reeognise the value of motor-racing successes. The next hatch of production engines is likely to he put in hand this month.
It will be seen that the makers have every reason to term the EWA a proper sports-car engine. It has required surprisingly little production developnient. Last June an improved rear oil seal was introduced, using ring-type seals in a cast-iron housing,, because above 6,000 r.p,m.–trte original design-maximum for the engine-occasional failure was eXperieneed, especially when owners elhninated the cantshaft-cover breather, causing excessive pressure to build up in the crankcase. Chapman lost a certain class win in last year’s T.T., when he. was ahead of many larger ears, due to the oilgauge pipe breaking at the T-joint with the valve-gear oil pipe; a new arrangement has since been adopted. In the Goodwood NineHour Race Watling-Greenwood had several dynamos born out as a result of the continual high engine speed. up to 7,000-7.300 r.p.m., necessitated by low-gear running on this circuit, so for 1956 the dynamo speed has been reduced and an improved rev.-counter drive developed.
What of the future ? It is ciumnan knowledge in racingear circles that ‘a new camshaft has been developed for the EWA engine. The Cooper-Climax which broke the Class G one-hour record at Montlhery had one of these cantShafts installed. in conjunct km with this camshaft, which gives greater lift and overlap, -a new induction system has been designed. However, this couldn’t be fitted in the restricted engine compartment of the Comier-Clintax, so only about half the available increase of pawer was realised. Even SO. on a hack-axle ratio of 4.1 10 1 a Max iinnin speed of just on 140 m.p.h. was obtained and, by the way. the. car was able to reach this speed within half a lap of the Montlhery traek after starting from rest in top gear, proisf that the new CHM COMO nr hasn’t spoilt the lower-end performance of tliis remarkable engine. Cidin Chapman has also used the new camshaft experithentally, hut again without the induction system which will be complementary to it. By the beginning of the tanning season Coventry-Climax expect that the experiments is ii Ii olex and Weber carburetters will have
concluded and that the new camshaft, induction system, and a slightly altered cylinder head to suit, will be available. Output should be increased by 10 b.h.p., to 85 b.h.p. at about 6,900 r.p.m.
It is significant that up to now the engine has been raced with the normal industrial camshaft. Its latest application is as a power unit for the new Albatross motor-boat, slightly modified and with the drive taken front what is the front of the car engine.
Each engine is bench-tested for 41. to 5 hours before delivery and is required to give 72 b.h.p. at 6,000 r.p.m. with dynamo and silencer in place; new engines are purposely not taken above 6,000 r.p.m., but it is commonplace for them to be returned after, say, 800 racing miles and for the output to have risen to 75 or 80 b.h.p. or even a shade higher. An old Morgan 4/4 is used as a mobile test-bed.
Apart from the FWA engine this old-established Coventry company has some interesting developments in hand for the future, but about these the Editorial lips have been sealed. Meanwhile, congratulations to Coventry-Climax on the excellence of their 1,100.c.c. race-winning sports-car engine.—W. B.