P-51XR “Precious Metal”: The Most Radical Mustang Reno Racer

The P-51XR Precious Metal is one of the most unusual aircraft ever derived from the legendary North American P-51 Mustang. While many Mustangs were converted into racing aircraft after World War II, Precious Metal became something entirely different. Engineers transformed the classic fighter into a powerful experimental racer by installing a massive Rolls-Royce Griffon engine and a rare contra-rotating propeller system.

As a result, the aircraft gained a distinctive appearance and extraordinary performance. Its long nose, large spinner and twin propellers immediately distinguish it from standard P-51D Mustangs. Today, Precious Metal remains one of the most recognizable aircraft associated with the famous National Championship Air Races.

The Mustang After World War II

The North American P-51 Mustang became one of the most successful fighters of the Second World War. Introduced in the early 1940s, the aircraft quickly proved its value when equipped with the Rolls-Royce Merlin engine. The Merlin provided excellent high-altitude performance and allowed the Mustang to escort Allied bombers deep into enemy territory.

However, after the war ended, thousands of surplus military aircraft became available to civilians. Many Mustangs were purchased by private pilots and aviation enthusiasts. Some aircraft were restored to original condition, while others were heavily modified for air racing.

In the United States, air racing soon became a popular aviation sport. The Reno Air Races in Nevada developed into the most prestigious competition for highly modified warbirds. In this demanding environment, engineers pushed piston-engine aircraft far beyond their original limits.

The Creation of Precious Metal

The aircraft that became Precious Metal was assembled in 1988 using components from several Mustang airframes. The project was carried out by World Jet Inc., a company well known for its involvement in warbird restoration and air racing.

The goal of the project was clear: build a Mustang capable of extreme performance in unlimited-class air racing. Instead of improving the original Merlin engine, the designers decided to install a much larger and more powerful powerplant.

They selected the Rolls-Royce Griffon engine, a British engine originally used in late-war fighters and maritime patrol aircraft such as the Avro Shackleton.

The Griffon engine was significantly larger than the Merlin and capable of producing more than 3,000 horsepower. Installing it inside a Mustang airframe required major structural modifications.

Technical Modifications

Transforming a standard Mustang into the P-51XR configuration involved several complex engineering changes.

Griffon Engine Installation

The Rolls-Royce Griffon engine is both heavier and more powerful than the Merlin. Therefore, the aircraft’s forward fuselage had to be redesigned. The nose section was lengthened in order to accommodate the larger engine and the propeller gearbox.

Additionally, the engine mounts and structural components were reinforced to handle the increased torque and vibration produced by the Griffon.

Contra-Rotating Propellers

One of the most distinctive features of Precious Metal is its contra-rotating propeller system. This design uses two propellers mounted on the same axis that rotate in opposite directions.

This configuration helps eliminate torque effects that normally occur with high-power piston engines. It also improves aerodynamic efficiency by converting more engine power into forward thrust.

Because of the gearbox required to drive the dual propellers, the aircraft’s spinner and nose profile became noticeably longer than those of a standard Mustang.

Modified Cowling and Cooling

The larger Griffon engine required a wider and reshaped cowling. Engineers also modified the cooling system to ensure proper airflow during high-power racing conditions.

These changes significantly altered the aircraft’s appearance while maintaining the basic Mustang airframe structure.

Racing Career

Once completed, Precious Metal quickly attracted attention at the Reno Air Races. Its unusual configuration made it one of the most visually striking aircraft in the unlimited racing class.

During qualifying runs, the aircraft reached speeds approaching 453 mph (approximately 729 km/h). These speeds placed it among the fastest piston-engine racing aircraft ever flown.

The aircraft was eventually owned and flown by American warbird pilot Thom Richard, who continued to operate the aircraft in racing and demonstration flights.

The 2015 Fire Incident

In 2015 the aircraft suffered a serious setback. While taxiing at an airport in Florida, a fire broke out and caused significant damage to the airframe.

Fortunately, the pilot exited the aircraft safely. Although the fire did not destroy the aircraft completely, the damage required an extensive restoration process.

Since that incident, efforts have been underway to rebuild and restore the aircraft.

Modeling the P-51XR Precious Metal

For scale modelers, Precious Metal is an extremely interesting subject because it combines the classic Mustang airframe with unique racing modifications.

Unlike standard Mustangs, however, no mainstream model kit represents this aircraft directly. Therefore, a conversion project is required.

The most practical starting point is a P-51D Mustang kit in 1/48 scale.

1/48 Scale Conversion Guide

To accurately reproduce the P-51XR configuration, several visible changes must be made to the base kit.

Nose Extension

The Griffon engine installation resulted in a noticeably longer nose.

In 1/48 scale, the model should be extended by approximately:

13–14 mm

This can be achieved by cutting the fuselage slightly forward of the firewall and inserting a plastic spacer.

Larger Spinner

The spinner used on Precious Metal is significantly larger than the standard P-51 spinner.

Recommended diameter in 1/48 scale:

21–22 mm

Contra-Rotating Propellers

The aircraft uses two five-blade propellers mounted in tandem.

In 1/48 scale the propeller diameter should be approximately:

81 mm

The spacing between the two propellers should be about:

3–3.5 mm

Cowling Modifications

Because the Griffon engine is wider than the Merlin, the upper cowling should be slightly expanded.

Adding approximately 1 mm per side using modeling putty will help reproduce the correct shape.

Paint and Markings

The aircraft is well known for its distinctive racing finish, combining polished metal with bright yellow markings.

https://en.wikipedia.org/wiki/Precious_Metal_%28aircraft%29?utm_source=chatgpt.com

https://www.mikekillianphotography.com/Aviation/PM2015/i-jWZJT7m

https://www.aerialvisuals.ca/AirframeDossier.php?Serial=228030

https://www.globalaviationresource.com/v2/2013/09/09/world-jet-inc-p51xr-n6wj-precious-metal/