Vintage Thing No.118 - RBN Special

If Cooper had made Coventry-Climax front engined cars, this is how they might have looked

I'd heard of this car several years ago from a brief article in the Imp Club magazine and especially liked the ally panels created on an English wheel and the use of a front mounted Imp engine .

This is a Hillman Imp special par excellence. The RBN actually uses the Chrysler Sunbeam block, a 928cc version of the Imp block used in entry level versions of these rear-wheel drive hatchbacks.The RBN also uses the Avenger derived gearbox from the same source.

I think that feature line that runs all the way round the car works especially well

However, the chassis is Triumph Spitfire, shortened by a foot and clothed in aluminium bodywork hand wheeled by its constructor, Philip Robinson, who took 18 months to build it.

The 928cc Chrysler Sunbeam engine responds just as well to tuning as the Imp engine. The bulge in the bonnet was for an earlier single carb

The engine is highly modified using traditional Imp tuning, namely hogged out to 1040cc with an R20 cam, twin forties, a special manifold and a ported head. Useful rev range is 3-7000 rpm with an 8,000 rpm red line and a maximum output of 90 bhp.

As it weighs only 10 cwt - about 500 kgs - so goes like the clappers.

Phil had a problem with the liner of number 3 cylinder, which dropped slightly and blew a gasket. Andy Jones then planed the block to desk all the liners evenly.

Cooling is by a Morris Minor radiator uprated to a three core element after the standard 2 core rad made it run too hot. There is no thermostat but there is a roller blind to mask the rad when warming up that the driver operates via a cable.


Phil made his own wishbones for the front suspension but used the original Triumph uprights. He added flanges on the front mudguards to prevent being flung onto the occupants and the brackets are very substantial as he doesn't like to see them waggling.

Phil made a tubular frame for the bodywork and clothed this in panels he made himself on a specially bought wheeling machine (I'd love to be able to do this) although the internal bulkheads are steel. He deliberately styled to resemble an early Cooper F1 racing car and I reckon it works.

There's no spare (now that's what I call risk management) and the battery live sin the boot to help weight distribution. The fuel tank is a 6 gallon affair from a Minivan. Phil said he gets 28 mpg, which sounded low to me, but he assured me that he drives it hard.

Here's another view of the engine. I am an Engine Punk, you know.

He's obviously a complete petrol head and while I quizzed him about his special he mentioned how much he enjoyed going Formula 1 racing in the sixties. Naturally, I assumed he meant to spectate but I am reliably informed by Bob Allan, Imps Club Spares Co-Ordinator, that Phil was actually racing. A quick search on Wikipedia did, indeed, turn up a Philip Robinson who raced alongside the likes of Jim Clark and Graham Hill, yet - and I hope this is soon rectified by someone better qualified than me - he's the only F1 driver listed who doesn't have a Wiki page of his own!