Rolls Royce Merlin Engine

 
 

The Merlin engines were a series of 12 cylinder, 60° "V", 27 liter, liquid cooled piston aircraft engines built during World War II by Rolls-Royce, and under license in the United States by Packard. They are widely considered to be among the most successful engines ever produced during World War II, and perhaps the finest piston engines ever built for aviation.  Merlins are still highly sought-after by aviation enthusiasts today.


In the early 1930s, Rolls started planning for the future of its aero engine development programs, and eventually settled on two basic designs. The 700 horsepower Rolls-Royce Peregrine was an updated, supercharged development of their existing V-12, 22 L Rolls-Royce Kestrel, which had been used with great success in a number of 1930s designs. Two Peregrines bolted together on a common crankshaft into an X-24 layout would create the 1,700 hp 44 L Rolls-Royce Vulture, for use in larger planes like bombers.  However, this plan left a large gap between 700 and 1,500 hp.  To fill the gap, work was started on a new 1,100 hp class design as the PV-12 – PV for "private venture" as the company received no money for work on the project. The PV-12 first flew on the front of a Hawker Hart biplane in 1935, using the new evaporative cooling system, then in vogue. The cooling system proved unreliable, and when supplies of ethylene glycol from the US became available, the engine was changed to the conventional liquid cooling system instead.


In 1936, the Air Ministry had a requirement for a new fighter aircraft with airspeeds that would eventually have to be over 300 mph.  Fortunately, two designs had been developed entirely as private venture exercises: the Hawker Hurricane and Supermarine Spitfire. Both were designed around the PV-12 instead of the Kestrel, and were the only British modern fighters to have been developed.  Production contracts for both aircraft were implemented in 1936. The PV-12 was instantly catapulted to the top of the supply chain and became the Merlin. First widely delivered in 1938 as the 1,030 hp Merlin II, production was quickly stepped up. The Merlin I had a 'ramp head' where the inlet valves were at a 45-degree angle to the cylinder. This was not a success and only 172 were made before the conventional flat head arrangement wherein the valves are parallel to the cylinder was adopted for the Merlin II.


Early Merlins were considered to be rather unreliable, but their importance was too great for this to be overlooked and Rolls soon introduced a superb reliability-improvement program. The program consisted of taking random engines from the end of assembly line and running them continuously at full power until they failed. They were then dismantled to find out which part had failed, and that part was redesigned to be stronger. After two years of this the Merlin had matured into one of the most reliable aero engines in the world, and could be run at full power for entire eight-hour bombing missions with no problems.  By the end of its production run, over 150,000 Merlin engines were built. It was eventually replaced by the Rolls-Royce Griffon, a development of the R engine.

Rolls Royce Merlin Engine - Mustang


Scale:                            1:15

Release:                        2005

Limited Edition:              50

Price:                             $1,800.00

Model Size:                   6”L x 2.5”W x 4”H

Base Type:                    Black Walnut

Base/Case Size:           9.5”L x 5.5”Wx 6”H

Availability:                    1 available