Getting in a spin
I was interested to read your piece on the Mazda Luce (December), and your comments on the 13A engine. I became a fan of these units after buying a Chevron B16 in 2002 and racing it for five seasons. The car came with a 12A, which had been thrashed by the previous owner in the States, and when it died of rotor-tip seal failure I put in a 13B built by rotary specialist Pip Gardner of WGT Developments in Cheshire. After a lot of fiddling with carburetion, the engine was dyno’d at 311bhp and 199lb ft.
These engines were astonishing: very powerful, completely reliable, simple and cheap to run. I think Pip charged £1500 to rebuild the 13B; for a BDG it was nearer £6000 – every 600 miles. Its smoothness allowed the FT200 transaxle to handle the power and torque of the 13B engine without any problems.
We ran the 13B for four seasons without laying a finger on it, and when I sold the car the engine was still as sweet as ever. One of its great beauties was that, after building it and getting it right on the dyno, there was nothing more you could fiddle with. Often I walked down the pitlane and found a BDG owner with head in hands because the injection was up the creek, there was a misfire or a big hole where there shouldn’t have been.
It was a low-compression engine so unfussy about fuel, to which was added a dose of oil to keep those rotor-tip seals happy. Engine oil was just as important for cooling as water. Plenty of oil and coolant capacity was vital; as long as this was built in, you had no problems.
When Mazda started shipping rotary cars to the West Coast it ran into huge problems. They were thirsty and dirty, which didn’t go down well with the oil crisis and environmental lobbies, but above all they suffered tip-seal failures, so Mazda threw in the towel. The racers kept on it, and with quiet help from Mazda’s engineers they solved the tip-seal problem.
I’m amazed there has not been greater use of these rotaries as race engines; cheap, simple, powerful and reliable – what’s not to like?
Stephen Minoprio
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