Bentleys run a single T4 with external gate.

IIRC compared to a RS500 T4, they have a slightly smaller flowing comp side, and a bigger ex side (well, its a full T4, rather than the RS500 which has a large T3 exhaust side).

Not much for such a big engine, but remember they dont rev, arnt huge power, and have to have huge instant responce, they quick whafters not sports cars.