Originally Posted by italiansedanman
Well, MG wanted a twin-cam MGA. They tried it, it was a bit of a disaster, so perhaps they should have used our twink from the beginning!!
Yeah its a shame about the MGA Twin Cam engine. Indulge me here and let me tell you what went wrong.
The Pre-war MG company, which by the way I regard very much as the UK counterpart of ALFA ROMEO in terms of its Motor Sport prowess. MG was a maker of very fine Single Over Head Cam engines which throughout the 1920's-1930's when combined with a supercharger and preselecter gearboxes (think selespeed but way better) allowed MG racing cars to punch well above their weight and mix it with the likes of ALFA and Bugatti. Cars like the Q type and the R Type were highly advanced thorobreds, NA Magnettes and Magnas kicked *** in the Mille Miglia and even Nuovolari drove one to victory at the Tourist trophy. MG also designed and ran speed record breakers, not the giant landspeed cars the likes of the Bluebird and the Golden Arrow but small 1100 cc versions that broke class land speeds.
After the war MG was pumping out as many sportscars as the postwar world especially the US could buy, but they were producing fairly boring mainstream production models based along the lines of the prewar T series. These T series cars were fitted with a very unsophisticated but somewhat "sporty" 1250 XPAG OHV engines with Twin SU Carbs. There was not the money, the time or the support to go back to the glory days of the Q and R types, Le Mans and Brooklands victories. So the OHV XPAG engines ruled.
Come 1954, the TF which was the third warmed over version of the T series post war has just been given a 1500 CC makeover, but sales have slumped thanks to the introduction of the fast sexy modern Austin healeys and TR2's. MG need to do something fast, they borrowed from a sleek experimental record breaker from 1952 and an MG Le mans special from 1953 and presto enter the MGA, one of the popular sportscars of all time.
The MG had an Austin B series engine, which was the new workhorse 4 cylinder for BMC at he time. The MGA B series was a 1500 unit OHV fitted with Twin Su Carbs, the car was capable of making 96 mph.
Pretty basic stuff right ?
June 1955 : MG enters three prototype MGAs in the ill fated 1955 Le Mans 24 hours. all 3 cars are standard push rod 1500 CC engines, but MG have been experimenting with a twin cam heads they try an unit based on the Austin B series block that they are already using in push rod form in the MGA and they also try out a Morris block. The Austin B series wins out in trials but it is too late to get a car ready for Le Mans that year.
Development continues, but it is nearly 3 years before MG release the MGA Twin Cam production car. Advanced for 1958 with a sweet twin cam unit, 4 wheel disc bakes (which ALFA did not have until the Giulia) and steel disc wheels that look like they cam straight off a Le Mans winnning D Type Jag, 115 mph 0 to 60 in 9.0 seconds. Everything sweet right ??
The MGA Twin Cam starts giving trouble from the start, warranty claims are causing massive head aches for the company as "Twinnies " come in from around the globe with complaints of conrods ventillating piston crowns etc etc etc. meanwhile on the race track the MGA Twin Cam is kicking *** in its class on both sides of the pond at Le Mans and Sebring. Why ? What is it about the works maintained twinnies that is reliable and why are street versions so troublesome??
Well it took em two years to sus it out and by then it was too late. You see the Compression ratio was way to high to cope with the fuels of the time. In the late 50's one couldn't be sure that you could get High Octane 100 Ron fuel everywhere and it was a combination of this and the way to high Compression ratio that was the issue. in 1960 they reduced the comp ratio slightly and what do you know no more hassles. It was too late, the bad reputation stuck, only 2166 MG A Twin Cams were ever made and MG drop the idea of making a Twin Cam version of the replacemnet to the A the MG B.
The long and the short of it was that the Twin Cam MG A failed because it didn't have anywhere near the development time, budget or commitment that a twin cam engined required from Scratch. In contrast that wonderful engine that we know and love so well in either 1300, 1600, 1750 or 2000 cc form had a hell of a long development time and as most of us are 105 drivers know that engine was around since 1954 a good 9 years at least before any of our cars saw it. So good that it was still being used through the Alfetta up till the end of the old spiders series. What a shame MG didn't take a leaf out of ALFAs book.
Still the MGA TWIN CAM is a very rare and desirable car these days, worth big bucks and a real buzz to drive. A Twiny driven in anger is a wonderful thing and the road equivalent of flying a Spitfire. I wish I owned one. The engine is a work of art but such a ***** to maintain compared to our superb creation from Milan.