The Dorman diesel engine business was bought in 1987 by Broadcrown and was later purchased by the Perkins Engines Company of Peterborough in 1993. The last Dorman-branded engine was produced in 1995, however the DNA of the Dorman engines lives on to this day in the form of the Perkins 4000, which is a development of the Dorman SE.
In 1998 Perkins sold the Ruston & Hornsby range to RHL Spares Ltd following the closure of the Dorman Diesels Central Spares Division in Lincoln. Formed by a group of experienced former Dorman employees to support the Ruston & Hornsby and Dorman Diesel engine ranges; RHL purchased the stock and rights to exclusively support the old Ruston & Hornsby range of engines. The RHL Spares business was purchased in 2006.
In September 2010 Perkins Engines agreed to sell all of the Dorman Diesels non-SE related parts business including all of the technical records and intellectual property relating to the ST, DA,Q, J, L, LS, P, Y, Monair, F, and DWD engine ranges.
Above right: a selection of historic Dorman literature taken from Grace’s Guide to British Industrial History.
Right: design department at Dorman Diesels factory on Tixall Road, Stafford, photo taken around 1985.