Rikki von Opel leads Colin Vandervell at Mallory
in 1972.
   
Mo Nunn is perhaps best known today for engineering the cars of a number of CART champions such as Emerson Fittipaldi and Alex Zanardi and he now runs his own two-car CART team. However many people don't realise the Nunn was a mean racer himself back in the days of the F3 1-litre screamers when he drove for the works Lotus team and then he subsequently became a constructor of F3 and F1 cars, the F3 cars in particular being very successful.
Originally Nunn intended to race in F5000 in 1970 but when the drive fell through he decided to turn constructor instead, with backing from Bernard Lewis he built the first Ensign in a lock-up at the back of his bungalow! Such was the success of this first chassis in 1971 that orders for more soon came and Nunn had to obtain premises and begin producing the cars seriously. In 1973 Rikki von Opel who had been racing an F3 Ensign asked Nunn to build an F1 car for him and as a result Ensign withdrew from F3. Ensign continued in F1 until 1983 although lack of a proper budget meant the cars only ever showed flashes of promise, notably when Chris Amon and Clay Reggazzoni were driving.
   
  
Alan Rollinson testing the Ensign at Silverstone in December 1970. As can be seen it was fitted at this time with a 1-litre engine.
 
Steve Thompson at Brands Hatch in October 1971.

The square tube spaceframe chassis, it extends well forward to carry the wide based lower wishbones.
The F3 Ensign was first displayed at the 1971 Racing Car Show although, as can be seen on the left, it was in fact testing prior to this time. Sometimes known as the F371 but more often as the LN1 it was an instant success with Bev Bond putting in some sterling drives, including several victories in the works car. Steve Thompson, David Purley and Mike Walker also winning in their examples. The chassis consisted of a square-tube space frame with stressed alloy side panels and was fitted with a conventional suspension set up although the wishbones were very wide based. Most noticeable was the very sleek bodywork with its neatly ducted side radiators. Three cars were built during the course of 1971.
   
  
Mike Walker finishing 4th at Rouen

Colin Vandervell in his Potterton car.
Initially the only noticeable change for the F372 was the sleek Alpine-like new engine cover with its built in wing. The Ensign certainly seemed to be the fastest car in a straight line but a weakness under braking led to mid-season revisions including lowered suspension pick-up points and a general all over tweaking. This certainly seemed to help and after a midyear slump the Ensign was winning again by season's end.
   
  
A second place for Mike Wilds at Mallory.
At the beginning of the season Ensign sold a number of cars that were unchanged versions of the 1972 chassis due to Nunn's preoccupation with F1. As their best drivers left for the March camp Dave Baldwin was recruited from Lotus to do some design work which resulted in a much improved car that allowed Brian Henton to win races at the end of the year but the effort required for Grand prix racing meant the end of F3 for Ensign.
   
  
Dick Parsons in the Smiths Crisps Ensign at Thruxton.
Although Ensign were no longer building F3 cars Dick Parsons raced a car that was entered as an F373/74. It would seem to be a 1973 car with the 1973 late season modifications that were carried out to Brian Henton's car (see above).
   
Drivers  
1971 F371
Bev Bond, David Purley,
Alan Rollinson, Steve Thompson, Mike Walker.
 
1972

F372
Bob Evans, Jeremy Gambs, Neil Ginn, Mike Greenwood, John Littler, Rikki von Opel, David Purley, Cavan Riley, Tony Trimmer, Mike Tyrrell, Colin Vandervell, Mike Walker, Mike Wilds.

F371
Ken Mackintosh, Ken Sedgley.

 
1973

F373
Mo Harness, Carlo Giorgio, Brian Henton, Tom Hilliar, Roberto Marrazi, Larry Perkins,
Lorenzo Sassi, Ole Vejlund, Mike Wilds, Roelof Wunderink.

F372
Roger Craven, Spencer Elton, John Littler, Jac Nelleman, Frank Scurria, Mike Tyrrell.

F371
Ken Sedgley, Roelof Wunderink.

 
1974

F373/74
Dick Parsons

F373
Arie Luyendijk.

F372
Frank Scurria.

   
1975

F373
Bob Howlings.

?
Buzz Buzaglo