Editing BMC B-series engine (section)

==={{vanchor |Twin-Cam}} engines===
A special Twin-Cam ([[DOHC]]) version of the {{convert|1588|cc|L|1|order=flip|abbr=on}} B-series engine was produced for the [[MG MGA|MGA]]. Output was {{convert|108|bhp|kW|abbr=on}} at 6700&nbsp;rpm in the high-compression (9.9:1) version and {{convert|100|bhp|kW|abbr=on}} in the optional low-compression (8.3:1) version. The engine block was cast iron, but the crossflow eight-port cylinder head was of [[aluminium alloy]]. Drive to the twin camshafts was by chain from a [[Gear train|gear-driven]], half-speed shaft running in the space that would have been occupied by the conventional camshaft.

This engine gained a reputation for being unreliable in service, especially in the high-compression version which needed high-[[octane]] fuel, but this has now been largely overcome. The piston burning habits — thought to be the result of [[ignition timing]] — was later discovered to be due to a vibration induced lean burn situation involving the float bowls, easily correctable by flexibly mounting the carburettors. A total of 2,111 cars were built, in both [[coupé]] and [[Roadster (automobile)|roadster]] versions.

A very few engines with the special displacement of {{convert|1762|cc|L|1|order=flip|abbr=on}} were produced for racing purposes.

Applications:
*1958–60 [[MG MGA#Twin-Cam|MGA Twin-Cam]]