By on May 23, 2014
image (16)

Photo: Bonhams

TTAC contributor Abraham Drimmer has a fine piece over at Road & Track about his favorite cars that resulted from collaborations between Lotus and other, usually much larger, automobile manufacturers. Each of Abe’s five choices are worthy of note in their own way: the Isuzu Impulse, the C4 Corvette ZR-1, the Lotus Sunbeam, the Lotus Carlton, and the DeLorean DMC-12, but Mr. Drimmer is a relative youngun, so I wasn’t surprised that left off of his R&T list was the original ‘tuned by Lotus but sold by another company’ car. It’s the Lotus tuned car that Lotus purists are most likely consider to be a genuine Lotus and not an Isuzu, Chevy, Chrysler, Vauxhall or DeLorean. In some cases it fetches prices north of its contemporary Elans. It has a pedigree that includes some of the greatest luminaries of British motordom and it helped to establish the foundation of a relationship that would eventually revolutionize motorsports. According to Lotus’ factory nomenclature, it’s a Type 28, according to the sales brochures it was the Ford Cortina Lotus and according to just about everybody else who knows about it, it’s called the Lotus Cortina.

image (7)

The Lotus Cortina grew out of the development of the Lotus Elan, first introduced in 1962. The first Lotus developed primarily as a road car was the revolutionary Elite that featured a fiberglass monocoque and was powered by a Coventry Climax engine. Though it was a technical success, finding a vendor that could reliably supply bodies of sufficient quality made from the then new composite material drove up costs, as did the pricey all-aluminum racing engine. As a result, economies of scale were not achieved and Lotus lost money on every Elite they sold. Colin Chapman was resolved that Lotus’ next road car would cost less to make and that it would be powered by something based on a mass produced engine. The young Cosworth company had shown some success tuning Ford’s “Kent” four cylinder engine, developed for the Anglia in the late 1950s. Using modern casting techniques Ford was able to make a cast iron engine block that didn’t weigh much more than one made of aluminum, however its potential was limited by the head design. Chapman decided that giving the Kent block a double overhead cam aluminum head with hemispherical combustion chambers, like that on the Jaguar XJ engine, would make sufficient power for his new road car as well as being the basis for a racing engine. He hired Harry Mundy, who with Walter Hassan had designed that same Jaguar engine, offering him a one pound sterling per engine royalty fee or 1,000 pounds up front. Since Lotus was a bit of a hand to mouth enterprise in those days, Mundy took the money, which he would later regret as eventually about 40,000 Lotus Twin Cam engines were made.

image (5)

The cross flow Twin Cam head has two valves per cylinder set at a narrow 27 degree angle to each other. Mundy used such a narrow angle to prevent interference with less expensive, conventional (i.e. non wedge) pistons. In development it was discovered that the theoretically non-ideal valve angle fortuitously resulted in more turbulence and more complete combustion. Cast into the head were intake runners that carried the fuel/air mixture from two two-barrel sidedraft 40DCOE Weber carburetors with short velocity stacks mounted inside an airbox connected to the air cleaner. When introduced, the Twin Cam had 105 horsepower, while later versions would have as much as 140. It’s a highly tunable engine that breathes and revs freely. Race versions can have 180 hp or more, but 165 hp is usually considered the limit for a streetable car.

allingtonfordcortinalot

By the time the Elan started production, the Kent block had been developed into the 116E version with 1,499 cc displacement and five main bearings. Chapman acquired one of the earliest 116E castings, put the DOHC head on it and sent Jim Clark out to race a Lotus 23 with it in a FIA Group 4 event. It was determined that some production blocks had thicker cylinder walls than others, allowing slightly larger bores. Those were bored out to 1,557 cc for production Elans. The most robust blocks were given another millimeter of bore, increasing displacement to 1,598 cc, perfect for the then new Group 2 production car racing rules.

image (13)

In the early 1960s the Ford Motor Company, under the slogan of “Total Performance”, embarked on a broad motorsports agenda that would eventually lead to great success at LeMans, Indianapolis and in Formula 1. Those big Ford wins would start in 1965, when Jim Clark won the Indy 500 at the wheel of a Lotus 38 powered by a Ford V8. Ford didn’t just decide to fund Lotus’ Indy effort out of thin air, the huge Dearborn automaker and the tiny British specialist already had success working together in Group 2 with a Lotus powered Cortina.

image (10)

Walter Hayes was a British journalist who went to work doing public relations for Ford and was instrumental in the Total Performance program. In time Colin Chapman would convince Hayes to commit 100,000 pounds of Ford’s money to fund the development of the landmark Cosworth Ford DFV engine that went on to great success in F1, but in 1962, it was Hayes who commissioned Chapman for Lotus to develop Ford’s Group 2 racing effort, to be based on the upcoming Cortina sedan, which was going to be launched in 1963.

image (42)

Hayes was in charge of the UK part of Ford’s 5 year plan to dominate auto racing and by mid 1962 he had heard of what Chapman and his boffins were doing with a Ford block and their own heads. Lotus has almost always existed in precarious financial circumstance, all the more so in the early days. Chapman saw the deal with Ford as a possible lifesaver for his company and in many ways it allowed the company to get established as a legitimate, albeit small, manufacturer of road cars. Ultimately, the deal with Ford made Lotus a household name among auto and racing enthusiasts.

image (49)

To go racing in Group 2, rules required 1,000 production cars to be made for homologation purposes. Final assembly was assigned to Lotus, which partly explains why the model is considered by brand enthusiasts to be a Lotus, not a Ford. It really was a deal that Chapman couldn’t refuse since the cars would be sold as Fords, by Ford dealers, with the huge automaker promoting the Lotus brand. Part of the relationship between the two companies also involved Ford supplying Lotus with components. In addition to the Ford engine block, the Elan used a Cortina based transmission and while the Elan’s differential housing is a custom aluminum Lotus casting, the internal parts are also sourced from the Cortina. That deal would incidentally benefit owners of Lotus cars and later Lotus restorers because many Lotus parts from that era also have a Ford part number, including everything that goes into making the Twin Cam engine.

image (62)

Lotus’ revisions to the Cortina were extensive and went far beyond just an engine swap. Bodies were pulled off the regular Dagenham production line to be modified on a dedicated line per Lotus designs and then installed with parts common with regular Cortinas like glass, heaters, lights and locks before they were shipped to Lotus’ factory in Cheshunt for final assembly.

image (57)

The 105 horsepower Twin Cam was given a cold air intake in the nose of the car and a larger capacity radiator than was used in the regular Cortina was installed. The Elan’s close ratio gearbox was used and it had an aluminum tailpiece and bell housing. A single piece driveshaft ran to the rear end.

The original coil spring A-frame rear suspension for the Lotus Cortina was too fragile. Custom leaf springs and radius arms proved to work just as well, and were cheaper to build.

The original coil spring A-frame rear suspension for the Lotus Cortina was too fragile. Custom leaf springs and radius arms proved to work just as well, and were cheaper to build.

Early Mk I Lotus Cortinas had a trick rear suspension that replaced the leaf springs with coils and located the solid rear axle with radius arms and a wide A frame member, similar to one of the rear suspensions used in the Lotus Seven. When that suspension proved to be fragile, Lotus reverted to leaf springs with reversed mounting eyes, along with the radius arms. The simpler suspension proved to handle just as well in competition.

image (52)

To match the lowered rear suspension, up front the springs were shortened and the McPherson struts were calibrated for stiffer damping. Longer, forged control arms were installed to eliminate wheel camber changes and a thicker anti-roll bar with longer ends was installed to reduce castor. A high geared steering box and different steering arms were used to increase the effective steering ratio while reducing the Ackermann angle.

YouTube Preview Image

Girling supplied the brakes with 9.5″ discs up front and 9″ drums in the back. A vacuum booster provided braking assist. The Lotus variant was the first Cortina model with power assisted disk brakes. Tires were originally bias ply, later switched to radials as they became available, and were size 6.00″ X 13″ mounted on 5.5″ wide steel wheels featuring chromed “dog dish” hubcaps (standard Cortina tires were 5.20″ X 13″ on 4″ rims).

image (17)

Inside, a 15″ wooden rim Lotus steering wheel was installed as were special seats with better lateral support, more rake and greater comfort.  A center console was installed featuring a elbow rest and a storage cubby. A custom aluminum faced cluster featured full instrumentation including a 140 mph speedo and an 8,000 rpm tach. Completing Lotus’ spec on the inside was a pear shaped wooden Lotus gear shift knob.

elan twin cam

The reason why the Ford factory did the body mods is that they were too extensive to be done post production. The battery tray was moved to the trunk/boot for better weight distribution. Reinforcing tubes were welded in between the top rear shock absorber mounts and the spring shackle mounts on each side of the trunk to stiffen the structure. The trunk floor was modified to restore clearance over the differential after the suspension was lowered. Early models had brackets welded in for mounting the rear suspension’s A frame, while later Lotus Cortinas had mounting brackets for the radius arms. The rear frame rails were reinforced. The hood, trunk lid and door skins were made of aluminium. Before shipment to Cheshunt, the bodies in white were in fact painted in Ermine White by Ford. Lotus added the signature Sherwood Green side stripes and rear valence. The green was presumably chosen because Lotus’ traditional racing colors were green and yellow. Lotus badges were painted on the rear flanks and a cloisonne badge was mounted on the right hand side of the front grille. The bodywork behind the grille was blacked out. The rear quarter bumpers from a Ford Anglia van were repurposed for the Lotus Cortina’s front end.

image (6)

The result was a car with an aggressive, purposeful stance, accentuated by the arrow shaped stripes. In the UK, because of the green stripe and lowered suspension, Lotus Cortinas were immediately identifiable from more mundane Cortinas. The car got rave reviews in both the UK and the United States. I haven’t been able to determine just how many of the 2,894 Mk I Lotus Cortinas made it to these shores, but Ford dealers here did sell the car in a left hand drive version.

clark-cortina

The well known image of Jim Clark cornering hard, lifting a wheel.

Production began in early 1963 and Chapman and the Lotus racing team spent much of the year preparing racing versions. The Lotus Cortina’s competition debut was in September 1963 at Oulton Park, where Jack Sears won his class in a works car. It was only the first win in an impressive competition career. In 1964 Jim Clark, who was used as a development driver for the car and who used a Lotus Cortina as his personal car, won the overall British Touring Car Championship for the Lotus works team. Clark cornering his Cortina on three wheels, with the inner front wheel a half foot off of the ground, a serene look on Clark’s face, has become such an iconic image that more than one artist has been inspired by it.

clark chris dugan 1

Artist Chris Dugan’s rendering of Jim Clark and his Lotus Cortina

The Lotus Cortina went on to dominate the 2 liter class in saloon road racing, often competing for outright wins. Factory cars were raced by Clark, Graham Hill, Peter Arundell and Jackie Ickx to considerable success and Sir John Whitmore won the 1965 European Touring Car Championship in a privately owned Lotus Cortina. The Lotus-Ford sedan just about owned saloon racing in 1965, with Jack Sears winning the C class in the British Saloon Car Championship, Jackie Ickx winning the Belgian Saloon Car Championship, and a Lotus-Cortina winning the Gold Star Saloon Car Championship in New Zealand. Other notable wins in 1965 were at the Nuburgring Six-Hour race, the Swedish National Track Championship, and the Snetterton 500.

rally cortina a2

Jim Clark may have gotten a wheel off of the ground but Bengt Soderstrom got all four wheels of his Lotus Cortina rally car airborne

Once the rear suspension was changed to the more durable leaf spring setup, the Lotus Cortina also proved to be a competitive rally car with factory driver Bengt Soderstrom winning the Acropolis and Royal Automobile Club rallies in 1966.

rally cortina

When the second generation Cortina was introduced in 1966, a Lotus version of that car was also manufactured and sold, but it wasn’t as hardcore as the Mk I Lotus Cortina and while it has its enthusiasts today, the Mk II isn’t nearly as collectible as the original.

67_KAK_Rallyt_Bengt_S_derstr_m_Gunnar_Palm_Ford_Lotus_Cortina_1st_1

What’s it like to drive? A complete blast. How do I know? Not too long after I got my driver’s license in the early 1970s, my older brother Jeff decided to replace his 1965 Buick Special convertible with a 1966 Lotus Cortina. Jeff taught me how to drive a stick shift in that car and when he spent a year servicing machinery on a kibbutz in Israel, I used the Cortina to drive home from college in Ann Arbor. Yes, it had all of the flaws of British cars of that era, we called it the “Gorktina”, the starter motors were particularly unreliable, however it jump started easily and once it was running it drove flawlessly. Fast, comfortable and it could carry your whole crew. Think of a BMW 2002, a tuned Datsun 510, or the 190E “Cosworth” Mercedes-Benz that our Editor in Chief pro tem so loves, before such cars existed. The handling was as you’d expect from Lotus, in fact it inspired a friend of our to buy an Europa and me to buy my Elan. We all knew that Jeff’s car was special. We’re not the only ones. Fifth Gear calls it a “performance car icon” and “the daddy of all super saloons”.

YouTube Preview Image

 

Chapman’s philosophy of soft springs and stiff shocks gave it a reasonably comfortable ride. Plus, it was quick. While 110 hp may not seem like much today, the car weighed less than 2,000 lbs and the Twin Cam pulls from idle and revs well enough that they came with governors in the distributor to keep things below 6,000 rpm.

Sir Jack Brabham, who recently passed away, leads Jim Clark's Lotus Cortina with a Mustang. Oulton Park, 1965

Sir Jack Brabham, who recently passed away, leads Jim Clark’s Lotus Cortina with a Mustang. Oulton Park, 1965. Competing in the 2 liter class, the Lotus Cortina challenged cars with much bigger engines.

Though in the UK the distinctive livery and stance made the Lotus Cortina highly visible, in the United States, particularly driving around Detroit where we lived, it was just an obscure British Ford. Since it was a small European sedan nobody driving a America muscle car with a small block or bigger V8 would think it was some kind of performance car. Of course, in the 1960s the measure of performance in Detroit’s car culture was straight line speed, measured stoplight to stoplight on Woodward or Gratiot. If things went well, and they usually did, at the next light, when the Mustang or Mopar driver would ask “Whachu got in that thing?!”, replying “A 96 cubic inch four cylinder” came with a certain amount of satisfaction (and pride in high specific output motors).

YouTube Preview Image

As mentioned, today Mk I Lotus Cortinas are highly collectible. With less than 3,000 made, they are far rarer than the Elans and Europas of similar vintage and while Elans have significantly appreciated, as folks like Jay Leno and Gordon Murray sing their praises, a nice Lotus Cortina can sell for more than the nicest Elan. A superb Elan today might sell for as much as $40,000. Last September at a Bonhams auction held in conjunction with the Goodwood Revival a ’66 Mk I Lotus Cortina sold for the equivalent of $73,703 and a month earlier at the Quail Lodge sale Bonhams hammered off a one owner, 6,200 mile barn find 1966 Lotus Cortina that sold for $115,000. The Lotus team car in the famous Jim Clark photo above sold in 2007 for £136,800 (US$ 230,723) including the auctioneers’ fee. Not bad for a funny looking English car with a 96 cubic inch four. If you’d like one for yourself, Bonhams will be selling a race prepped ’65 with 170 hp and a limited slip rear end this fall at Goodwood.

Modern photos courtesy of Bonhams.

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can get a parallax view at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

Get the latest TTAC e-Newsletter!

16 Comments on “Mk I Lotus Cortina – The Original Lotus Tuned Car...”


  • avatar
    snakebit

    A great account of the Lotus Cortina Mark 1. Like the BMW 2002 and Datsun 510, it showed small sedans could be just as exciting to drive as ponycars, and as reported, it lead the way. This story reminds me of the account by auto writer Jamie Kitman of attending an auction in the UK for cars from the Lotus corporate collection, and Jamie snagging the gold Cortina Lotus Mark 2 that was Colin Chapman’s personal car. Again TTAC, a great story, people.

  • avatar

    Thank you, Ronnie! I was thinking the same thing, when I read Drimmer’s article–where is the Cortina?

    Cars like the 2002, VW GTI and Cosworth Mercedes 190 owe much of their existence from the Cortina. I wish Ford and Lotus still had a partnership, not that Ford needs it considering the Fiesta ST. But some limited edition Lotus Focuses would be cool…

  • avatar
    davefromcalgary

    Damn that is a cool car. Look how tiny that engine appears in that engine bay!

    My dad has often commented that his Cortina GT (I don’t know what year) was one of his favorite cars of his youth.

  • avatar
    tjh8402

    Great article Ronnie. Wonderful history of a fascinating car. Makes you wish it was this easy to take something mundane and make it something special. Yes, Ford has done something impressive with the Fiesta and Focus ST models, but I think the conversion was far more complicated than this (seeing as the base cars are already pretty complex machines). Also, I don’t see them establishing a racing pedigree like this Lotus, nor are they likely to be as out of the box competitive on track as the Lotus was. I hope Lotus continues to stick around. There is so much engineering talent available there. Also nice to see how committed Ford was to motorsports at that time. Wish they’d take that sort of lead again. Formula 1 and Indy are not the same without them, yet for so many Americans, they have no idea that Ford has a history of being one of the top companies in international motorsport, with a record to rival Ferrari or Porsche.

  • avatar
    ExPatBrit

    That pic of Brabham and Clark made me tear up.

    The best drivers of the day racing sedans as well as Formula 1/ 2 cars.

  • avatar
    scroggzilla

    A fine article on one of my favorite homologation/factory tuner specials, Ronnie. A few bits of pedantry: In addition to the works racing efforts, Alan Mann Racing found success in the ETCC with their red and gold liveried LoCorts, usually with Sir John Whitmore at the wheel. Bob Tullius’s Group 44 racing campaigned Cortinas between 1965-67,with Bob Tullius, Buck Baker, and Tony Adamowicz taking turns in the driver’s seat. Lastly, Colin Chapman built a single Cortina with a fully independent rear suspension, which served as Jim Clark’s ‘company car’ up until his death in 1968.

  • avatar
    Lorenzo

    In 1971 when I was in the Navy in San Diego, there were a few of these, and at least one was “saved” by the Cortina’s racing reputation.

    The big, burly guys from Operations and maintenance – steel workers, pipe fitters, welders – drove big American iron and thought so little of the Japanese subcompacts, they once picked up a sailor’s Honda 600 and left it on the second floor landing of the enlisted men’s quarters. One sailor I knew had bought a Cortina from his uncle and driven it from Seattle, and parked it in the same lot used by the O&M guys.

    The O&M guys were looking it over and I went over and told them it was a Ford, made in a Ford factory in England. They were sceptical, but fortunately, another guy from O&M came over and told the rest about the Cortina’s racing record, and they left the car alone. No telling what they might have done to it.

  • avatar
    wmba

    To quote, yet again, from Cosworth by Graham Robson:

    ” “The head had been designed by Harry Mundy,” Keith (Duckworth) relates, “then drawn up by Richard Ansdale. Colin (Chapman) approached us, not only to make a racing version, but to sort it out to go into a production car. It wasn’t all bad, but at the time the head joint wasn’t sound, the head structure wasn’t any good, and its ports didn’t look like ports ought to look like. By that time, we (Cosworth) thought we knew a lot about ports — we tended to bore them as far as possible, to keep them straight, to make sure there were no valve guide bosses to get in the way, because we trying to take air around the bend and through the valve with as little disturbance as possible.

    “We had, after all, got more than 100 hp/litre from the pushrod 105E engine, which was GP power of only five years previously, and were managing to run that pushrod engine up to 10,000 rpm, nearly 10,500 rpm. I didn’t think the ports were as free-flowing, or as straight, as they should be. We did think we had a fair idea of how you should get air, at high velocity, through ports, and to work properly. So we straightened up the ports — we just arbitrarily redesigned them — then we added a bit of structure to the head.”

    As Miles Wilkins noted in his book, Lotus – the Twin Cam Engine: “Therefore, the final shape of the head, including the oil-breather arrangement, was produced by Keith Duckworth.””

    Ronnie, I remember the arguments about this from 1964 on. Motoring News which I got every week from my car-racing nut aunt in England during the ’60s, used to feature this ongoing controversy. But look who Ford asked to design a 3 litre Formula 1 engine. It wasn’t Harry Mundy who designed the DFV with narrow-angle valves and two cams under one cover per bank. It was Duckworth, and the modern pentroof 4 valve cylinder head was born. As he later boasted.

    As for that original rear suspension, no wonder it failed. I had been looking at Chev rear suspensions during my high school years, wondering how, with just fore-and-aft up and down location with three trailing arms, it could accomodate body roll and one wheel drops into potholes, when the suspension, on the face of it, only allowed straight up and down movement. The answer is Giant Rubber Bushings that squished just like all these modern day 5 link rear IRSs with impossible kinematics.

    Look at that Lotus Cortina rear suspension drawing, as I did 50 years ago, and you could see the bushings were too small, and that freakish forces would occur at the rear diff housing joint in roll. It was pretty obviously not good. Yes, they broke. No wonder they reverted to leaf springs.

    • 0 avatar

      wmba,

      Thanks for mentioning Ansdale’s and Duckworth’s role. The piece was long and one can’t include everything. Also, the royalty story with Mundy is cute and the design undoubtedly originated with him. FWIW, Both of Cosworth’s founders had worked for Chapman and they were more comfortable working for Lotus as contractors and suppliers than as employees.

      I suppose the Cosworth BDA, designed by Mike Hall while Duckworth was working on the DFV, more faithfully expresses the design philosophies of Cosworth than the Lotus Twin Cam, which had a number of hands involved in its development.

      The Twin Cam has some serious design flaws. The original head had no tappet liners on the exhaust side, causing wear. The water pump built into the front engine cover (requiring taking the head off to fix a water pump) is so insane that there are a number of aftermarket fixes. The distributor sits right below the big carburetors, which makes setting the points and timing a bit difficult. All of the oil supplied to the head drains back to the sump via a rubber fitting.

      But when it runs, it’s sweet.

  • avatar
    Kenmore

    Love the Angry Buick butt.

  • avatar
    Joss

    Cortina: Ubiquitous, 60′s English Pop’s Fedora.

    Lotus Cortina: Super Dave helmet edition.

    If you ask me Pop won cause Lotus didn’t go Mk II & III Cortina.

  • avatar
    Ron B.

    Lotus did build MkII Cortinas and I still kick myself for not saving one decades ago which had fallen into the hands of a young teen driver …and was being mercilessly flogged until it threw a rod because of a lack of oil. The worst lotus cars have to be the protons…. less said the better.

  • avatar
    BigDuke6

    Great story Ronnie. BTW, anyone that has commented HAS to belong to the 50 years + club. Including ME. Sad that this story doesn’t generate the same amount of participation as some new lame-ass SUV/CUV.

  • avatar

    The first car I ever drove, back in 1976, I was 17 years old, the car was a white 1.5 liter 1964 Cortina.
    I loved it back then but at the same time I wanted a newer one.


Back to TopLeave a Reply

You must be logged in to post a comment.

Subscribe without commenting

Recent Comments

New Car Research

Get a Free Dealer Quote

Staff

  • Contributing Writers

  • Jack Baruth, United States
  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Vojta Dobes, Czech Republic
  • Matthias Gasnier, Australia
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Cameron Aubernon, United States
  • J Emerson, United States