Restoring the Merlin

Historic Flying has chosen Universal Airmotive of Chicago as its preferred supplier for engine restoration. This is what they say about rebuilding the Merlin:

“The Rolls Royce or Packard built Rolls Royce Merlin is one of the finest piston engines ever conceived. Employing technology fifty years ahead of its time, the Merlin engine is a true fighter thoroughbred.

The Merlin is still state of the art in piston engine technology, far beyond any automotive technology today. Rolls Royce’s goal was to create an engine that produced as much horsepower as its weight and displacement, and do so at high altitudes. This goal was achieved through the development of exotic alloys and metallurgy, and through advanced design techniques.

After a distinguished service history during the Second World War, the Rolls Royce Merlin continued in commercial service in Britain and Canada into the late fifties. These engines, most notably the six and seven hundred series, were the subject of intense testing and modification until as late as 1960.

Commercial operators logged more time on their Merlins than the military operators did by far, and consequently they had problems military overhaulers never had to deal with. In addition, it was not cost effective to replace every part when it was worn past service limits, so Rolls Royce developed thousands of repair schemes and modifications to salvage otherwise unserviceable parts, and to extend the running life of parts within the engine. These repair schemes and modifications were the product of enormous amounts of engineering, development and testing before approval by the British Air Ministry.

Warbird engines are now starting to accumulate the same time in service that commercial engines of the mid-fifties saw, making major rework necessary on some components. Some overhaulers are inserting automotive technology into the Merlin in order to meet this need. Sometimes with fair results, sometimes with disastrous results, but never with the same reliability as Rolls Royce parts and repairs, which still surpass most automotive technology today. No overhauler can expend the resources to engineer and test changes to the Merlin to the same level as they were tested by Rolls Royce, and most of the modifications and repair schemes that Rolls Royce developed for the commercial operators can be used to maintain the military engines with perfectly reliable results. No guesswork, and no lost aircraft due to questionable engineering or some overlooked variable. Rolls Royce did the testing on the ground so you won’t have to in the air.

At Universal Airmotive Ltd. we install no automotive technology into our Merlin engines, only Rolls Royce repair schemes and modifications coupled with genuine Rolls Royce and Packard parts. We have the only set of genuine Rolls Royce overhaul tools in existence, not just the tools to disassemble and reassemble the engine, but tools to rework every component as well. “

Historic Flying is confident that Universal Airmotive is the leading authority on the rebuild and restoration of Rolls Royce and Packard Merlin and Griffon engines and that the engines they deliver fully live up to our rebuild philosophy.