| Advanced Engine Research |
| Ailsa Craig Engines |
| Alta Car and Engineering Company |
| Associated British Oil Engine Company |
| B. Hick and Sons |
| Barclay Curle |
| Blackstone & Co |
| Boulton and Watt |
| British Polar Engines |
| British Racing Motors |
| British Seagull |
| John Brown & Company |
| Centrax |
| Cosworth |
| Coventry Climax |
| Coventry Victor |
| Crossley |
| Crossley-Premier |
| Cummins UK |
| Davey, Paxman & Co |
| William Doxford & Sons |
| Fairfield Shipbuilding and Engineering Company |
| Firth Brown Steels |
| Fleming and Ferguson |
| L. Gardner and Sons |
| George Forrester and Company |
| Gibson Technology |
| GKN |
| Gourlay Brothers |
| Green Engine Co |
| Hart Racing Engines |
| Ilmor |
| Anthony Inglis (shipbuilder) |
| J. A. Prestwich Industries |
| J. Tylor and Sons |
| JCB (heavy equipment manufacturer) |
| Judd (engine) |
| Kelvin Diesels |
| John G. Kincaid & Company |
| Lister Petter |
| R A Lister and Company |
| J&H McLaren & Co. |
| Henry Meadows |
| Morris Engines |
| D. Napier & Son |
| Robert Napier and Sons |
| Norman Engineering Co |
| Palmers Shipbuilding and Iron Company |
| Parsons Engineering |
| C. A. Parsons and Company |
| Paxman (engines) |
| Peter Hooker |
| Petters Limited |
| Powertrain Ltd |
| Protean Electric |
| Radical Performance Engines |
| Ransomes & Rapier |
| Ricardo PLC |
| Robey & Co |
| Ruston & Hornsby |
| Smith-Clayton Forge Ltd. |
| Turner Manufacturing Company |
| Vickers |
| Villiers Engineering |
| Vosper & Company |
| W.H. Dorman & Co |
| Wallsend Slipway & Engineering Company |
| Weslake |
| White and Poppe |
| White’s Marine Engineering Company |
| William Beardmore and Company |
| Yarrow Shipbuilders |