Posts Tagged ‘Zerex Special’

2022 McLaren MCL36 Mercedes (McLaren)

For the last few decades the aerodynamics of racing cars have been developed with the aid of complex computer modelling and sophisticated wind tunnel testing. Things were a bit different in 1964 as Bruce McLaren finalised the specifications of the first McLaren built from the ground up in his own factory – as against the Tasman Cooper T70s he and Wally Willmott built at Cooper in later 1963 – the McLaren M1.

The Kiwi’s head was full of ideas, he was up to his armpits doing countless laps of Goodwood helping to get the best from Ford Advanced Vehicles’ new Ford GT40. His nascent Bruce McLaren Motor Racing Team was racing the Cooper Oldsmobile, a further mutation of the ex-Roger Penske Zerex Climax Special. Then there was his day job with Cooper as leader of their F1 team. Not to forget Cooper’s own Climax engined ‘Monaco’ sporty, or Lola’s Mk6 GT Ford, he had done plenty of laps in those too.

Bruce McLaren at right, and Eric Broadley – lead design engineer – in the brown shirt at left and Ford GT40. It’s the May 1964 Nurburgring 1000km, race debut of the car, DNF suspension. Note the radiator top-ducts (unattributed)

Never was a man better placed than Bruce right then to know exactly what a winning sports-racer’s attributes needed to be. After all, in June he’d won the Players 200 at Mosport in front of some of the best in the world (Dan Gurney, Jim Hall, AJ Foyt, Roger Penske and Ken Miles) aboard his just finished Cooper Olds aka Zerex Special. This very finely honed grandfather’s axe had just copped a new McLaren built centre cockpit section and 3.9-litre Traco modified Oldsmobile V8 to replace the lissom Coventry Climax FPF four. More on the Zerex Special here; Roger Penske’s Zerex Special… | primotipo…

While testing the Cooper Olds at Goodwood, McLaren’s mechanics, Wally Willmott and Tyler Alexander got tired of continually removing the front section of the Cooper Olds bodywork, just to check brake and clutch fluid levels. So they decided to cut a small access hatch above the master cylinders, it was hinged at the front and held shut with a Dzus fastener at the rear.

Cooper Oldsmobile and a busy Tyler Alexander in the Goodwood paddock, June-July 1964 – still with the Mosport ‘quickie’ stack exhausts and winning numerals attached (W Willmott)

On one of Bruce’s test runs the fastener came loose. McLaren noticed the flap lifting, showing negative pressure just where he thought it would be positive, and would therefore hold the flap shut.

Bruce, Wally and Tyler discussed the phenomena. They concluded that if it was a low-pressure area, they could exhaust hot air from the water and oil radiators through the top of the body to assist cooling. The method until then had been to exit the air around the front wheels.

They decided to change the radiator air exit, so Tyler set-to with tinsnips and cut a big square hole in the body behind the radiator. The flap of alloy wasn’t cut at the top but folded down behind the radiator to deflect the air upwards.

Tyler Alexander takes the tinsnips to form the Cooper Olds’ radiator exit duct. The smaller flap which popped open is clear, Goodwood (W Willmott)

After his test run with the changed nose, George Begg wrote, “Bruce reported that the front of the car now had better grip, this helped reduce high speed understeer. In turn this meant a larger rear spoiler could be employed so as to again balance the car’s handling at high speed.”

“This was a big breakthrough as it meant both better cooling and higher downforce from the body. Back at the factory an alloy panel was made and fitted to smooth the flow of air through the big square vent in the top of the bodywork.”

The Cooper Oldsmobile raced with the top-duct fitted for the balance of its life.

Bruce McLaren was the class of the field in the August 1964 RAC TT at Goodwood until clutch failure ended the Cooper Olds run – complete with now more refined bonnet top radiator duct (Evening Standard)

This innovation – I’m not saying McLaren were the first to do it, check out the duct on the Ford GT40 shown above that May – was then deployed on all front-radiator McLarens. Right from the first M1 sportscar – with the exception, for some reason, on the 1967 single-seaters – until the 1971 side-radiator M16 Indycar headed in a new aerodynamic direction initiated by Lotus’ epochal types 56 and 72.

McLaren’s approach quickly became the global paradigm. It really was a major advance, one borne of a dodgy Dzus fastener and the computer like brain of Bruce Leslie McLaren, with not a data-base or wind tunnel to be seen.

(GP Library)

Bruce McLaren aboard his brand new McLaren M1 Oldsmobile at Goodwood in mid-September 1964.

It’s his first run with bodywork – note the neat radiator duct – his first laps of the spaceframe machine were completed sans body, a practice followed for years with McLaren’s single seaters and sportscars.

The McLaren M1’s Engine at this stage was a Traco prepped circa 310bhp 3.9-litre aluminium V8, gearbox a Hewland four speed HD, wheels are Cooper magnesium. More on the McLaren M1 here; Lola Mk6 Ford, Bruce McLaren and his M1 Olds… | primotipo…


The finished product during the Bahamas Speed Week at Nassau in December 1964.

Bruce placed second to the Hap Sharp/Roger Penske driven Chaparral 2A Chev in the feature race, the Nassau Trophy, despite giving away a litre or so and several years of ongoing development to the Rattlesnake Raceway boys.

Wally and Tyler sending Bruce away after a pitstop during the 405km race – 56 laps of the 7.2km Oakes Field Course.

Apart from the two factory Chaparrals (Penske jumped into Sharp’s car after an off-course excursion), the classy field of outright contenders included Pedro Rodriguez in a NART Ferrari 330P, Walt Hansgen’s Scarab Mk4 Chev, Dan Gurney’s Lotus 19 Ford and Jerry Grant’s Chev engined 19.

It was a great start for McLaren, orders for the cars poured in, this led to the deal Teddy Mayer concluded with Elva cars to produce customer McLarens, an incredibly smart and lucrative way to deal with the punters…

(Getty – Bernard Cahier)

Reference and photo credits…

‘Bruce McLaren: Racing Car Constructor’ George Begg, Wally Willmott, GP Library, LAT Images, Getty Images – Bernard Cahier



Roger Penske fits the mould of racer-billionaire rather nicely, as a model he doesn’t look quite so comfy…

I found these Zerex Special shots, as is so often the case lookin’ for something else. They are interesting in an historical context in the journey this chassis took. F1-16-61 was built as a Cooper T53 GP car then converted into an edgy central seat sportscar by Penske and his team. It then evolved into a two-seater and finally passed into Bruce McLaren’s hands as a foundation piece in his journey to ultimate Can-Am domination a few years later.

So, in the McLaren pantheon, its an important car. I wrote about it early in 2015, click here to read the article;


Cooper fans will easily pick the origins of the chassis. Both the photo date, September 1963, and the two equally sized seats reveal this as the third evolution of the car.

When the SCCA regulators, aided and abetted by some very cranky competitors and car owners cracked- the-shits with Roger’s innovative Rule Bender they re-wrote the regs to ensure sportscars were two seaters rather than Rogers seat-and-a-bit approach. This is the bendy-tube rebuild of the car at that time to meet the new rules…


James Drake




penske zerex

Roger Penske aboard his devilishly clever Zerex Special sportscar in 1963…

By 1962 Penske was a well established competitor. While later his friend and driver Mark Donohue coined The Unfair Advantage phrase in racing, Roger himself contrived a clever plan to develop a very quick sportscar for the lucrative US series.

After careful study of the SCCA Rulebook Penske concluded that while the sports car regulations required said cars to have two seats, the rules didn’t define their dimensions.

Roger’s cunning stunt involved resurrection and fitment of a very small passenger seat and sportscar bodywork to a Cooper T53 Climax F1 car (chassis #T53 F1-16-1) crashed by Walt Hansgen during the 1961 US Grand Prix at Watkins Glen.

Walt was launched over Olivier Gendebien’s Lotus, Olivier having spun and re-entered the circuit right in Walt’s path. Briggs Cunningham, the Cooper’s owner, sold the damaged car to Penske in the ‘Glen paddock less engine.

hansgen cooper

Walt Hansgen Cooper T53 Climax T53 F1-16-1, the Zerex donor car, behind is Penske in his Cooper T53 Climax. US GP Watkins Glen 1961. Both cars 1.5-litre Coventry Climax FPF powered (Ron Nelson)

zerex puerto rico grid

Zerex Climax looking absolutely superb on pole as Penske settles himself into the cockpit for the 200 mile Puerto Rico GP in 1962. He won from Tim Mayer’s Cooper T57 Monaco and Dan Gurney, Porsche 718 WRS (Getty Images)

The car was then repaired, rebuilt and transformed by Roy Gane and Penske himself  by fitting a wider alloy body with round and square tubing and added brackets to support the new body and mini-seat. Its first race, still 2.7-litre Climax FPF powered, was the LA Times Grand Prix at Riverside in October ’62.

It was an International event that attracted the world’s best including Jack Brabham, Graham Hill, Dan Gurney, Innes Ireland and Masten Gregory as well as world class Americans Penske, Jim Hall, Hansgen, Ken Miles, Lloyd Ruby and others.

The Zerex, to all intents and purposes a current GP car with an all-enveloping body, promised to be competitive!

At a distance, even up close, the car appeared to be a single seater in contravention of the rules, as soon as it was unloaded in the paddock the SCCA was deluged with protests.

Watched by a large crowd of media, mechanics, spectators and drivers Penske calmly undid the Dzus fasteners attaching the left side panel to reveal a small, cramped, passenger seat, whereupon the lanky Philadelphian attempted to insert himself into said seat…The car was kosher, legal to the letter of the rules, Penske was canny enough to have the SCCA Chief Technical Inspector see the car when it was being concepted and approve it as being compliant.

penske in car

Nearly in…Penske sees the funny side even if the competition doesn’t before the car takes to the track, LA Times GP 1962 (Dave Friedman)

The car won three events in late 1962; at Riverside during its first race meeting from Jim Halls Chaparral 1 Chev, at Laguna Seca and the Puerto Rico GP.

The Riverside and Laguna races were USAC sanctioned. The car was protested but USAC allowed it to run, but storm clouds were brewing from some very pissed off, wealthy, influential car owners.

la times 62

LA Times Riverside 1962. Penske leads # 63, the Hansgen Cooper Buick, #5 McLaren Cooper Monaco Climax, #8 Jerry Grant Lotus 19 Buick, #66 Jim Hall Chaparral 1 Chev, #3 Masten Gregory and #26 Lloyd Ruby both Lotus 19 into turn 1 lap 1. Penske won (Dave Friedman)

zerex pqurto

Penske on the grid at Puerto Rico. The car looks simply fantastic, workmanship a treat (Dave Friedman)

pr circuit

In the winter of 1962, the entire chassis centre section was cut, shut and widened by Penske’s team to provide a seat either side of the Zerex centre-line to meet the quickly-tightened 1963 rules…

The car (lets call it Evolution 3 in this form) was sold to John Mecom, the body modified to conform, a new windshield and roll bar was added and the machine repainted in Mecom’s blue and white colours.

zerex in paddock

Zerex in the paddock, circuit unknown in 1963 with full roll bar and space for second seat, offset driving position-Zerex Evolution 3. Climax FPF and CS5 ‘box on display, as are simple brackets to retain the body and truly ‘orrible but seemingly effective curvy frame (unattributed)

The Zerex raced throughout 1963 in this form winning two SCCA national events at Marlboro Motor Raceway and Cumberland. Across the Atlantic it was first in the Guards Trophy at Brands Hatch in August, Roy Salvadori placed second in a Cooper Monaco Climax that day.

mecom owned la times 63

LA Times GP, Riverside 1963. Owned by Mecom, still driven by Penske it was  second to Dave McDonald’s Cooper Ford ‘King Cobra’ (Dave Friedman)

la times 63 penske and macca

LA Times GP ’63. A fantastic 200 mile race initially led by Halls Chaparral, DNF. Here is the later dice between Penske and McDonalds’ Shelby Cooper Ford for the lead, McD prevailed in the 289cid small block Windsor engined Cooper (Dave Friedman)

See this YouTube footage of both the 1963 LA Times GP and 1964 Sebring 12 Hour…

The Zerex is historically significant in that it was sold to Bruce McLaren after Nassau in 1963. It was effectively the first in the long line of very successful McLaren sportscars which became the dominant force in Can-Am/Group 7 racing from 1967…

In 1962 Bruce, a factory Cooper driver, and Penske shared a Cooper Monaco Maserati at Sebring. Bruce later wrote, “After that race I came back to England and asked Charlie Cooper if I could run the sports car side of the Cooper Car Company because I felt sure there was a tremendous market for this type of car to use an American engine for American racing. I was convinced at that stage that sportscar racing was going to really boom providing there were cars available, and that it would be a great market for an English manufacturer. Charlie turned me down flat.”

Penske moved on from the Zerex as it became less competitive. He drove a Chev engined Cooper for Mecom and later a Chaparral before retiring from driving in late 1964, having signed to race for Jim Hall again in 1965.

The Zerex Climax was still sitting in John Mecom’s workshop together with an aluminium Traco modified Oldsmobile F85 engine which had never been fitted to the car. Bruce bought it and shipped it back to the UK, fitted with a 2.7 FPF. The Olds F85 (the block was used in much modified form, as the basis of the 1966 F1 Championship winning Repco Brabham RB620 3-litre V8) was on a pallet.

Bruce raced it with the 2.7 Climax and slightly modified bodywork (Evolution 4 if you like) in the Aintree 200 where he defeated Jim Clark’s Lotus 30 Ford, and in the Silverstone International where he won again, this time from Salvadori’s Cooper Monaco Maserati 5-litre.

aintree 200 sports 64

Start of the 1964 Aintree 200. L-R: #87 John Coundley Lotus 19 Climax, #95 Tony Lanfranchi Elva Mk7 BMW, Jack Sears AC Cobra, Bruce is on the right in the Zerex Climax. McLaren won from Jim Clark, Lotus 30 Ford and Sears’ Cobra (unattributed)

The day after Silverstone Zerex was stripped at Bruce’s new, modest, dirt-floor workshop in New Malden, South London where the chassis rebuilt from just behind the front suspension to just ahead of the rear suspension with a new McLaren designed centre-section welded in. The work was done by Wally Willmott and Tyler Alexander.

In its Penske modified form the car lacked the torsional rigidity to cope with the additional power and torque of the Olds V8. The (Evolution 5) chassis was far stiffer that the Zerex modified frame. The main chassis longerons performed dual purposes as structural members and as conduits for oil and water from the respective radiators to the engine. A Colotti gearbox from one of Bruce’s Tasman Cooper T70s was mated to the Olds engine.

With no time to fabricate a new exhaust system, the car was flown to Mosport with eight stub exhausts poking up through the tail, there he won first time out.

zerex mosport mac laren 64

McLaren victorious upon debut of the (then named) Cooper Oldsmobile with its new chassis centre section and Olds engine. Players 200, Mosport, Canada 1964 (unattributed)

Given the sensitivities about Jack Brabham’s departure from Cooper and construction of his own cars with Ron Tauranac, calling the car a McLaren was not going to wash with Charlie and John Cooper so the hybrid was entered as a Cooper Oldsmobile at Mosport.

Back in the UK he won the Guards Trophy at Brands Hatch in August, then starred at Goodwood’s Tourist when he started from pole, led and set fastest lap before retiring.

With all of his research complete – with the aim of building a McLaren sportscar – Bruce sold the car, via John Mecom and Teddy Mayer to Dave Morgan. The Texan raced it throughout 1965 and 1966 in the US and Nassau. From Morgan the car was sold to Leo Barboza in Venezuela and then on to two other South American owners.

The prototype McLaren M1A Oldsmobile appeared later in 1964, dominance was not too far away!

Continually modified, the hybrid Cooper T53/ Zerex/McLaren Olds maintained its Unfair Advantage for three years…

zerex in venezuela

Cooper T53 aka Zerex aka Cooper Olds in Venezuela shortly after its arrival in 1967 (unattributed)

In late June 2022 the Zerex/Cooper Olds was shipped to the UK and is to be offered for sale by Bonhams during the September 2022 Goodwood Revival Meeting.

Check out this Nostalgia Forum Thread for more information and photographs of this wonderful car; Taproot of the McLaren marque – The Nostalgia Forum – The Autosport Forums


zerex paddock 2

Paddock shot in 1963, circuit unknown. Cooper T53 standard front suspension comprises upper and lower wishbones and coil spring/damper units. Evolution 3 widened chassis and offset driving position, and second full size seat to comply with end of ’62 tightened rules is clear (unattributed)

zerex butt shot

Zerex butt shot in 1963. Beautifully fabricated aluminium body, circuit unknown, Pensacola perhaps (unattributed)

cooper mosport

Mosport ’64 colour shot of Bruce’s ‘new’ Cooper Olds – ain’t she sweet? (Bruce McLaren Trust)

Bibliography and Credits…

The Nostalgia Forum generally and Doug Nye’s posts on topic specifically, Bruce McLaren Trust, MiniWerks Forum. Photos credits David Friedman, Ron Nelson and the Bruce McLaren Trust


zerex ad

The ad which inspired this article I spotted in a pile of Road and Track magazines I bought. I was well aware of the Zerex Special, if not the infinite detail. The thing I didn’t know or care about was the derivation of the Cooper’s name. Penske secured sponsorship from Dupont to promote their Zerex antifreeze, not a product ever available in Australia, so now I know!