Jaguar V12 Racing Engine Recreated for Modern Use

Jaguar never used its V12 racing engine, but the ‘tera’ is ideal for a modern project car.

Back in 1966, Jaguar chief designer Claude Bailey created a unique V12 racing engine for the company’s XJ13 Le Mans Prototype. The plan was for this massive engine, which was designed specifically for racing, to help Jaguar dominate LeMans with all 12 cylinders roaring as the sleek racer rocketed down the Mulsanne Straight. Sadly, this V12 engine never saw racing duty, as the company opted to get out of endurance racing.

Instead, Bailey’s V12 was re-engineered as a single overhead camshaft design and used for road use. The ensuing V12 was still a great engine in the likes of the E-Type, XJS, and XJ12, but it fell well short of Bailey’s original design.

Fortunately, Bailey’s design has been recreated by British sports car builder Building the Legend, allowing those folks who are building a classic Jaguar road car or race car to rely on this legendary power plant.

Jaguar V12 Becomes ‘tera’

The V12 engine offered by Building the Dream is called the tera with a lower case “t” and it is as close of a replica as you will find to Claude Bailey’s race engine in the 1960s. While the original engine was intended to measure 5.0-liters, the road version was a 5.3-liter mill. The modern version is even larger, being offered in 6.1- or 6.8-liter variants. The smaller engine has a bore of 96 millimeters by 70 millimeters while the larger displacement option measures 96 millimeters by 78.5 millimeters.

All of the tera V12 engines feature an 11.7-to-1 compression ratio and the cylinder heads feature a 2-valve, over-square architecture with chain-driven camshafts. The engine features 12 individual injection units and buyers can pick between an era-correct Lucas mechanical injection system or a modern electronic system. All of these engines have a rev limit of 8,000 to 8,500 rpm, and all of that engine speed surely leads to a sweet sound under hard throttle.

The tera can be uniquely built for any classic Jaguar project car, whether you are looking to go racing or just cruise your local strip. As a result, horsepower output ranges from 250 to 650 and torque levels vary from 300 to 600 lb-ft. Needless to say, a naturally aspirated V12 with 650 horsepower and 600 lb-ft of torque would make any classic Jaguar very, very fast.

Introduction of tera

While there is plenty of information on the Building the Dream website, the tera V12 will make its grand debut later this month at Race Retro on February 21 through 23. At that event in Stoneleigh Park, Coventry, the company will have an engine on hand for closer examination, along with company representatives who can answer any questions about this unique custom engine. We can expect that the company will also have one of their custom cars which is also based on the 1966 Jaguar XJ13 Le Mans Prototype.

Photos: Building the Dream

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Patrick Rall

"Before I was old enough to walk, my dad was taking me to various types of racing events, from local drag racing to the Daytona 500," says Patrick Rall, a lifetime automotive expert, diehard Dodge fan, and respected auto journalist for over 10 years. "He owned a repair shop and had a variety of performance cars when I was young, but by the time I was 16, he was ready to build me my first drag car – a 1983 Dodge Mirada that ran low 12s. I spent 10 years traveling around the country, racing with my dad by my side. While we live in different areas of the country, my dad still drag races at 80 years old in the car that he built when I was 16 while I race other vehicles, including my 2017 Dodge Challenger SRT Hellcat and my 1972 Dodge Demon 340.

"Although I went to college for accounting, my time in my dad’s shop growing up allowed me the knowledge to spend time working as a mechanic before getting my accounting degree, at which point I worked in the office of a dealership group. While I was working in the accounting world, I continued racing and taking pictures of cars at the track. Over time, I began showing off those pictures online and that led to my writing.

"Ten years ago, I left the accounting world to become a full-time automotive writer and I am living proof that if you love what you do, you will never “work” a day in your life," adds Rall, who has clocked in time as an auto mechanic, longtime drag racer and now automotive journalist who contributes to nearly a dozen popular auto websites dedicated to fellow enthusiasts.

"I love covering the automotive industry and everything involved with the job. I was fortunate to turn my love of the automotive world into a hobby that led to an exciting career, with my past of working as a mechanic and as an accountant in the automotive world provides me with a unique perspective of the industry.

"My experience drag racing for more than 20 years coupled with a newfound interest in road racing over the past decade allows me to push performance cars to their limit, while my role as a horse stable manager gives me vast experience towing and hauling with all of the newest trucks on the market today.

"Being based on Detroit," says Rall, "I never miss the North American International Auto Show, the Woodward Dream Cruise and Roadkill Nights, along with spending plenty of time raising hell on Detroit's Woodward Avenue with the best muscle car crowd in the world.

Rall can be contacted at QuickMirada@Yahoo.com