The Chrysler 360 Rotomaster turbocharged version fitted to about 30 Beaufighters and 25 Brigands apparently has a major flaw in engine control systems as originally configured and supplied by Bristol and Rotomaster. The flaw is with ignition timing which needs to be massively retarded under boost conditions, and the set up originally supplied by Bristol is very hit and miss. If the ignition is not retarded quickly enough by the distributor set up then you get massive detonation.

Any turbo charged car maintained by Bristols or where the owner has taken advice from them will have been fitted with a MSD Ignition system (part number MSD 6BTM) which is controlled by a MSD control knob (part number 6BTM 6462). The control knob allows the user to dial in the extent of retard under boost conditions from NIL to 3 degrees per pound of boost pressure. Once set up correctly the knob is best hidden, at least from a retard like me. You will of course appreciate why straightaway! The exact set up depends on fuel quality used and the set up of the turbo wastegate.

Below are copies of the instruction manuals. Please click the appropriate heading to download a copy.