WAM has its origins in 1994, embarking on the blank sheet design of an all new 2 Cylinder, 2 stroke diesel prototype with the aid of a government SMART grant.

By 1997 the first flight of a prototype form of the engine had taken place, resulting in several awards including the DT Millennium Product Award in April 1999. Also in 1999, the three cylinder WAM 120 engine was unveiled to the public, with the first flight in a Europa aircraft following on the last day of December.

Production development continued, with the first production engine installed and flying in a Thorp T.211 in May 2003. For production to be established, WAM required more extensive facilities including automated test cells capable of operating 24 hours per day. Much of the following year was spent on seeking funding to facilitate this, with part of the funding requirement finally secured in March 2004. Although this was not the full level of funding required, it allowed WAM to move from its initial limited facilities in Buckinghamshire to new facilities in Dursley, Gloucestershire, including space for stores, limited production assembly and two fully automated engine test cells.

In 2006 a significant review and restructuring of the business was undertaken, including a thorough review of the baseline design and principles, with a number of key goals :

• The current 3-cylinder design to a production standard, as the WAM-100 LSA, having resolved a number of pre-production issues, culminating in certification to ASTM F 2538 with a TBO of 1000hrs.
• Successful re-location to initial premises at Staverton Airport, Gloucester, with new engine test bed facilities.

Major design innovations commenced development creating an improved ‘2nd generation’ design, including:

• New, lower cost piston and connecting rod design,
• Increased bore and stroke for increased power output within the same 3-cylinder package.
• New cylinder head and combustion system including a new pre-combustion chamber for improved TBO at higher engine outputs, with significant SFC improvements, and negligible smoke emissions the package comes out at a similar weight.

The 2nd generation engine required significant modifications to the key components, primarily the cylinder head, combustion chambers, pistons and connecting rods.

In 2008 the first initial testing confirmed the target performance goals. An additional benefit was that noise and vibrations were also noticeably reduced.

In early 2010, WAM moved into a custom built facility at Staverton Airport, Gloucester providing admin and design offices, stores and inspection areas, a workshop area sufficient to accommodate build up to 30 engines per month or greater, and the engine test cells, with space for a further dual engine test cell, and specialised fuel pump test rigs etc.

Since then ongoing testing has been undertaken achieving durability on the revised connecting rod and piston assembly and the new head and pre-combustion chambers.

In late 2012 endurance cycles to FAR33 format were successfully completed. Based on this success the prototype parts for the development commenced on the 4 cylinder engine.

The four cylinder engine, with a 167HP output in its initial build is now running successfully on the test bed, and ready to undertake full production tooling.The four cylinder WAM-167BB represents an important and exciting step forwards for the business, as it opens up a much wider range of aircraft suitable for this engine.