Although it’s an all-time classic, the MGA Twin Cam was far from trouble-free. For a start, it was an expensive engine to build, and that extra cost was passed on to the customer – a mere 2111 were sold during the late 1950s, and for those that did unreliability reared its ugly head. The engine gained a reputation for piston damage, and because of this few original cars survive. With a 110mph top speed, they were fun while they lasted. Visual differences between the Twin Cam and other MGAs were kept to a minimum, making these excellent Q-cars.
info from Octane