This weird racer is an ethanol-fueled go-kart

07th April 2022
Adam Wilkins

In the 1950s, 500cc Formula Three was popular in the UK, the US and Scandinavia. Three constructors were particularly prolific: Cooper and Kieft in the UK, and Effyh (pronounced the same as ‘FE’) in Sweden. As with so many historic racing cars, the Effyh featured here was adapted in its later career in an effort to keep it competitive, and it has been preserved in its Bryntam Tyddyn Special form. But, while it may have a Welsh name, its period racing history is all Swedish and American.


Having spent its early racing career in Sweden, it moved to America where it was raced by State Senator T Newell Wood at the circuit he hosted on his own estate: Brynfan Tyddenn (Welsh for hilltop manner). Current owner Martin Shepperd takes up the story: “There were two engines used in the day, JAP or Norton. Everyone wanted Norton because it was faster and more durable more than anything. The JAPs were more torquey, but for long races the Norton was the one to go for.”

The Effyn was encumbered with a JAP engine, so Wood was naturally keen to switch to a Norton unit, but there was a problem: the Effyh chassis was too small to accommodate the better engine. Martin: “He decided to cut the car in half and put on the back end of a Cooper. He imported all the parts from Cooper and bought a Ray Petty Manx Norton engine, which is still in there. He welded the car back together and raced it for a couple of years. He had his own race on his estate, a 35-mile race. Unfortunately, someone died in one of the races and he stopped racing. The car was left in a barn until the 1970s.”


Martin found the car for sale in New York where its owner was struggling for reliability. “They’re very difficult to set up in term of fuel,” says Martin. “If you don’t get enough fuel into them, they tend to get so hot the magneto will go down or they will seize. You really need to know how to set this car up in terms of fuel.” Heat is an issue anyway, since the engines are air-cooled and designed to be fitted to a motorcycle. Getting enough air around them in a car’s engine bay is a challenge.

“The guy I bought it from never finished a race. The engine always blew. Because I’ve raced 500s – I’ve had Cooper Mk12s and Keifts – I know how to set them up,” says Martin. They run on ethanol and, despite the modest 500cc capacity, only achieve 5mpg. “They blow most of the fuel out of the exhaust!” The car remains almost completely original. “There are no new parts on there, apart from the seat which has been recovered and the steering wheel, and I put a rollbar on there; I’ve had a few of these cars and I rolled one so it’s a safe thing to do.”


Martin’s first outing in the car was at Zandvoort, at which time it was untested. “Because it’s so much longer than the original Effyh, there was a real problem with the front suspension – a patter at high speed. At 70 or 80mph, both wheels were juddering at a tremendous speed. It was so bad that at Zandvoort, when I went to take the very high-speed turn at the end of the start/finish straight, the steering arm had snapped and I just went straight on. Luckily there was a gravel trap.

“We’ve been working on it and made modifications: different angles and we’ve tried different spring rates on the front. We’re getting there. Every race we’ve been at, it’s got better and better. It’s going to be a test over the next couple of days to see where it is. I’ve raced this car three times at Goodwood and finished in the top ten.”


This, despite the fact that the Bryntam Tyddyn is heavier than its opposition. “The original car was 1950 so they were using pretty heavy steel. As Cooper and Kieft developed, they used much lighter tubing. And because it’s so long, they’ve added a lot of weight into the car. This is probably 20 or 30kg heavier than an original Cooper, and that’s a lot. When you put a big guy like me in there it makes it even heavier. It does fit me though, and I’m 6ft 2in. That’s one of the advantages of it being so long.”

It’s a challenge keeping any 500cc Formula 3 car in top condition, says Martin, “They’re difficult to keep going. There’s very heavy vibration. If you don’t wire lock it, or if you don’t glue it, it will fall off it’s as simple as that. It’s a direct mounted engine, single-cylinder, 500cc. It puts out 46PS (34kW). It’s an amazing power unit, one of the greatest engines ever built. It’s interesting, it’s a one-off and that’s why I like it. I like the curiosity one-offs and getting them going. It’s all about reliability. They’re great fun to drive. It has a fixed diff across the back so it drives like a go-kart. The skill is really not to brake, don’t scrub any speed off and when you hit the corners try to get the car into a four-wheel drift. If you have the courage to get them drifting, it’s just fantastic.”

It’s cars like this that make the Members’ Meeting presented Audrain Motorsport such a unique and unmissable event, and you can be sure there will be plenty more small-capacity single-seaters four-wheel drifting around Goodwood at 79MM.

Photography by Pete Summers and Christopher Ison.

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