Welcome to Twiniminis

This site is all about 

"Twin Jag Mini"  

620 AXE 

Read about its history 

and recent re-build.

Summary Article

From Morris Mini Minor 848cc to Twin engined Jag Mini 2950cc.

In 1960 Gordon Allen bought Morris Mini Minor Registration Number 620 AXE for his wife to learn to drive in. At that time he had an engineering and tool making business and his spare time was spent on modifying engines, mainly for motorcycles.  He enjoyed owning various cars but favoured Jaguars.  His wife did not take to driving and the Mini became little used.  Having driven the Mini, Gordon got to like it and admire its driveability (of course he would!).  Naturally the driving experience is enhanced when more power can be added, so various tuning parts were fitted, mainly from Alexander and Speedwell.  Gordon’s thoughts then turned to racing the Mini and so in 1961 a number of saloon car races were entered.  See photo 1.  The Mini ran well at Silverstone and Gordon won his class and was presented with a Colibri cigarette lighter by the sponsors.  The next day at Brands Hatch Gordon lost control of the Mini and rolled it, the incident being captured on a photo.  See photo 2.


Thankfully Gordon wasn’t hurt but the Mini would need a replacement bodyshell.  The car gained a 1,000cc Formula Junior engine which Gordon had to adapt to drive the Mini transmission by fitting the tail end of a Mini crank onto the inline engine, Formula Junior crank. 


You’ve never got enough power, so for the 1962 season the engine capacity was increased to 1150cc by fitting larger 66mm pistons and a longer stroke 997 Cooper crank.  The car was successful in numerous races and would do a lap of the old Silverstone Club circuit in 1min 18 seconds.  See photo 3.


Gordon had driven up to this point but he had to concede that a competitor – Rod Embley was a better driver.  In early 1963 he noticed from an advert that Rod was selling his car to raise funds for a marriage and house purchase.  Gordon got in touch and suggested he would build a better race car if Rod would drive it. 


Gordon felt that he could not get any more power from the “A” series 1150 – remember that there were no 1275cc bigger block engines at this time.  Therefore during the 1963 season he fitted a modified 1500cc Ford engine onto a Mini gearbox.  The gearbox casing was extended to accommodate the Ford block.  A special aluminium cylinder head, made by Ted Martin was fitted. This had 2 inlet valves and one exhaust valve per cylinder operated by push rods.  (I need one of these heads if anyone can help?)  Twin Weber carburettors stuck out at the front which necessitated a bulge in the front of the bonnet.  See photo 4. 


This car was an instant success with a win on its first outing at Snetterton.  Other wins followed but the most notable race was at Mallory Park on 22/9/63 when the Mini came a close second in both the heat and final behind John Adams Team Tourist Trophy 3.8 Jaguar, thrilling the crowds in the process. 


Towards the end of the season the engine put a conrod through the side of the block at Mallory Park and that was the end of this successful combination. 


For some time Gordon had been considering what could make the car even faster and more reliable.  He wanted to go to a hemi type head as used in Jaguars and the new Lotus Elan/Cortina.  He tried to obtain a Lotus head but these were all required to fulfil orders for new cars.  High performance engines usually had shorter strokes and bigger bores and with his engineering knowledge and connections he reckoned he could create the engine he wanted by having his own block cast.  Being into Jaguars he happened to have two six cylinder Jaguar 2.4 litre engines spare – with hemi type heads. 


As Gordon relished an engineering challenge he thought why not convert the cylinder head into 4 cylinders from 6?  The centres were the same as on a Ford on cylinders 1,2,3 and 6 so he cut out  the number 4 and 5 cylinder section and rewelded the two ends back together.  Special 4 cylinder camshafts had then to be made from steel billets and these were based upon Coventry Climax profiles, which were popular racing profiles at that time.  The Jag pistons were too long and heavy, so an alternative was found from a Vincent Black Shadow motorcycle, which also had a hemi-head.  The Jag conrods could be used but the crank – a Ford 1500cc one, had to have the big end journal sizes increased to accommodate the Jag rods by welding and then grinding smooth.  A Mini crank tail was brazed into the end of the Ford crank.  The gearbox from the 1963 season could be reused.  This was already fitted with Speedwell close ratio gears.  This engine was 1475cc and produced around 115bhp at 6,000rpm.  See photo 5.


At this time the saloon car modified class was seeing more and more extreme modifications, for example Jaguar engines in smaller saloons, Buick in a Cortina.  So Gordon thought why not put two engines in the Mini?  So the whole process was repeated for a second engine and modified gearbox.  The car then became known as “Twin Jag Mini”.  It raced with the 2 engines in the 1965 season and did well.  The most memorable race was at Silverstone on August Bank Holiday Monday 1965 when the highlight of the meeting was the closely fought first and second places between Twin Jag Mini and the 4.7litre V8 engined Mk1 Ford Cortina of Doc Merfield.  The Cortina won by a small margin when the Mini had gear selection problems during the last three laps.  Twin Jag Mini did win at Silverstone on 11/9/65 and also held the 3 litre class record. 


At the end of 1965 significant repair work was needed on one of the engines and by now Cooper “S” engines were available, so Gordon decided to fit two Cooper “S” engines of different capacities to try and make the car understeer less.  This was not a success and it spun fairly easily when tested by Roger Bunting.  It came very close to rolling and Gordon decided his nerves could not take much more.  His health was not good at this time anyway, so he decided to give up with the idea.  I have also heard that as the modifications in this class were getting out of hand, the rules changed to outlaw twin engine racers. 


The car was dismantled and the “S” engines went into more conventional Minis.  The Twin Jag Mini engines went through various owners.  One was subsequently raced in South Wales at Llandow for some years, whilst the other was just kept by the same owner for spares.  Amazingly the two engines were not separated.  In 2010 I managed to purchase them and other parts from the car.  Then followed 3 years of tracking down more missing parts but sadly not the bodyshell .  Therefore a Morris Mini Minor shell in Old English White from the correct date in 1960 was located and enough parts assembled to be able to reclaim the original registration number. 


I now have the better of the two engines running again and installed in the front of the car. See photo 6.  The second engine and gearbox have some parts missing which need to be remade as they are non standard and this will take time and money.  Eventually it is hoped to get both engines back working in the car. 


The sight and sound of this early “Special Saloon” up and running again would be of great interest to those who enjoy modified Minis.  It would be a fitting tribute to the engineering vision and talent of Gordon Allen who sadly passed away in 1984. 


If anyone has any photos, film, further information or personal memories relating to this car’s history I would be very grateful to hear from you.   


The photographs in this article were copied with the kind permission of Mrs Allen and she retains the copyright. 


Neil Preston 

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