Round 3 of the Vintage Sports-Car Clubs “Formula Vintage” event at Cadwell Park was a refreshing change from the more modern machinery. The event was well attended with plenty of strange and unfamiliar (to me) cars
Mark Walker’s absolutely brilliant GN Thunderbug caught my eye with its unique appearance as I wandered through the paddock.
It has a patina on it and it’s taken nearly 30 years to get that look with stubborn stains. I go over it with an oily rag and some WD40. There is a bit of paint missing on the top where I barrel rolled it at Phoenix Park about 20 years ago.
Motorsport News 15 Aug 2018
The 4.2 litre vee-twin engine revs to just 1600 rpm taking it to a maximum speed of around 90 mph. The barrels are from a V12 radial aero engine and the transmission is 4 speed chain drive. Only the rear wheels have brakes. Mark also drives it on the roads.
There’s an excellent video from the Goodwood Road and Racing YouTube channel of Mark Walker talking about and driving the Thunderbug.