Posts Tagged ‘Chaparral 2D Chev’

Jim Hall on the front row of the grid, a locale he became quite akin to and fond of in 1964/1965- Laguna Seca in May 1965, Chaparral 2A Chev…

1965 started fantastically for the boys from Midland, Texas with a mighty win over twelve hours at Sebring against the best in the world from Ferrari, Ford, Porsche and the rest- Jim Hall and Hap Sharp took pole, fastest lap and the victory.

The team contested the US Road Racing Championships using the fibreglass chassis 2A Chev- those cars in 1964 won Corry Fields, Laguna Seca, Watkins Glen, Meadowdale and Mid Ohio- Jim Hall took the chequered flag in all of these events with the exception of Mid Ohio when his Chaparral business partner, Hap Sharp triumphed.

Sebring 12 Hour 1965- MG Bridge, the Hall/Sharp winning Chap 2A Chev goes inside the Ryan/Tidwell Porsche 904, behind is the second Hissom/Jennings Chap 2A, the famous deluge of rain which pretty much flooded the place is yet to come ( N Smuckatelli)

 

Jim Hall and Dan Gurney, Chaparral 2A Chev and Lotus 19B Ford during the LA Times GP at Riverside in October 1964 (E Rickman)

 

Roger Penske, Chaparral 2A Chev, LA Times GP 1964 (E Rickman)

In 1965 the Chaparral rout started at Riverside in May when Jim again won and continued through Laguna Seca, Bridghampton and Kent in early August before Hap won at Continental Divide and Mid Ohio in the back-half of August before Hall won the USRRC season-ender at Road America in early September.

Jim Hall on the way to another win, Laguna Seca in May 1965- Chaparral 2A Chev (T Palmieri)

 

Hap in the Corkscrew on the way to second at Laguna in 1965, Chap 2A Chev, Monterey GP in October (W Hewitt)

 

To the winner go the spoils- Jim Hall Laguna USRRC round May 1965 (J Christy)

On 10 October 1965 the more conventional aluminium monocoque 2C Chev made its debut, and won in Jim Hall’s hands at Kent, the 2C formed the basis of the 2E 1966 ‘definitive’ Can-Am challenger. For 1966 the highly popular, successful and growing popularity of sportscar racing in the United States was recognised with the creation of the first Can-Am series all of us got to know and love even across the other side of the Pacific.

Chaparral campaigned the 2E in the Can-Am and 2D Chev coupe in FIA endurance championship events- the team took their first win in that car at the Nürburgring in 1966.

The evolution of the all Chaparral’s, most racing cars for that matter is ongoing, particularly so the lads from Midland in a constant quest for evolution and occasional revolution.

Hall in the 2C Chev during the 1965 Nassau Trophy weekend- led the race until suspension failure when Hap Sharp took over (unattributed)

Traditionally the pro-series of races succeeded the US Road Racing Championship in the latter months of the year with rounds in both Canada and the US. Chaparral opened their 1965 ‘Autoweek Championship’ with a win for Jim in the Canadian Grand Prix at Mosport aboard a 2A in late September 1965- the new 2C made its winning debut at Kent in October 1965- Jim won the Pacific Northwest GP from Hap’s 2A.

At Riverside Hap won in his updated in body 2A, with Jim a non-starter after an accident resulted in suspension damage which could not be made good in time for the 200 mile LA Times Grand Prix. A fortnight later in ‘Vegas Hap won again in his 2A with Jim third in his similar car- Walt Hansgen was second in a John Mecom Lola T70 Ford.

As you will see looking at the various photographs the 2A evolved quite a lot in appearance in from early 1963 to late 1965 and its pretty tricky to pick Hap’s late ’65 fibreglass chassis 2A from Jim’s late ’65 ‘spankers aluminium chassis 2C- see below the wonderful 2A cutaway drawing which inspired this piece.

The cutaway drawing is of the first Chaparral 2 (the A appellation was applied later) which made its race debut during the LA Times GP Riverside weekend of 13 October 1963, so my story should have started about there really, but lets see if we can bridge that gap from this point. So, another nutbag poorly planned piece…

Chaparral 2A and 2C Chev Design and Technical Specifications…

The Chaparral 2A of 1964/5 had evolved enormously from the original car depicted above- the LA Times debutant went like a rocket that weekend leading from pole until sidelined by an electrical fire after four laps despite using off the peg quick solutions such as a Colotti Type 37 four-speed gearbox, Lotus uprights hubs and wheels and front and rear suspension, Cooper steering rack and Girling brakes, not to forget the Chevrolet V8.

Whilst the car was utterly conventional in terms of its suspension front and rear- upper and lower wishbones and coil spring damper units and an adjustable roll bar and inverted lower wishbone, single top link, two radius rods, coil spring damper units an adjustable roll bar using magnesium uprights at both ends- the cars chassis, gearbox and body were far more edgy.

The overall design parameters for the Chap 2 chassis were laid down by Jim Hall and Andy Green of PlasTrend in Fort Worth- Hall plucked Green from the aerospace industry and backed his move to the private sector by becoming his first client- called for an overall weight of 150 pounds and a torsional rigidity of at least 3000 pounds/feet per degree.

The ‘tub’, made of fibreglass reinforced plastic (FRP), comprised pairs of ‘torque boxes’ running down each side connected by bulkheads at each end of the cockpit and extended to the rear suspension mounting points and beyond. It extended right to the cars outside contours (as can be seen in the photographs), up to form the bottom of the door openings, inward to the sides of the Chevrolet V8 and to the drivers elbows and knees in the cockpit. It took full advantage of the sportscar’s overall size to get maximum rigidity from the torque-boxes (the stiffness of a torque box is proportional to its cross-sectional area) and does two jobs in forming part of the car’s outer skin.

At the time of its introduction the chassis was claimed to be the stiffest in motor racing. In the same way that Andrea de Cesaris proved the shuntability of John Barnard’s carbon-fibre McLaren MP4 Ford at the dawn of the eighties- its parent is the Chaparral 2, so too did Jim Hall put it to the test when he used the chassis he damaged at Mosport in late 1964 to win at Sebring in early 1965 partnered by Hap Sharp.

The same principles were applied to the lighter 2C aluminium frame for late 1965 which was closely related to the Chev Corvette GS-2 or ‘actually crafted by Chevrolet’, depending upon your source, we will come to in a little while.

Photograph of a Chaparral ‘fibreglass reinforced epoxy’ chassis from the Library of Philadelphia Collection. ‘…made entirely of fibreglass reinforced epoxy. Moulded in eleven pieces and assembled with an adhesive, the rivets maintaining alignment and gluing pressures. The engine bay is at the bottom with suspension mounting points outboard. Integral seats are above, passenger’s feet fitting into the dark opening at the front (top) of the chassis. The rectangular area will be cut down to form the dashboard cum bulkhead, and in the illustration (ute is justaposed to help with providing an idea of size) hides the front suspension mounting points. The round holes are for access to interior mounting points and the fuel tank…Chaparral designed by Jim Hall…with chassis elements designed and fabricated by Andy Green of PlasTrends…’

 

Chevrolet 3 speed and reverse spur gear non-syncro gearbox downstream of a torque converter (D Kimble)

The Chaparral 2 initially used, as mentioned above, a Colotti 5-speed manual gearbox until sufficient testing miles at Rattlesnake proved the durability and performance advantages of a Chevrolet designed and built automatic transaxle, the advantages of  which included  reliability, avoidance of driver error in terms of missed shifts or over-revs, and reduction in shock-loads to other components in the drivetrain. From a drivers perspective braking can be more accurate without the need to heel ‘n toe

The auto boxes were first raced at Laguna Seca in 1964, Hall and Sharp later claimed that it was only after a discussion between Dave McDonald and Dan Gurney after Mosport three meetings later after they listening to the cars in close company, that Dan asked Hall about the type of gearbox he was using.

The compact Chevrolet made unit comprised a hydraulic torque converter and compact two speed (three speed from the 2E) transaxle usually cast in magnesium. The ‘automatic’ was really operated manually. Before starting the driver engaged first gear and pressed the brakes with his left foot, releasing it upon ‘taking off’- literally. Gear changes to second (and top in the 3 speeder) were made by easing the throttle and moving the gear lever- downshifts were made similarly with a blip of the throttle. Those of us who have lost the use of a clutch have operated our Hewlands similarly. All Chaparral braking was done with the left foot- this left a foot free to operate the ‘flipper’ which we will come to shortly.

Suspension development was continuous from 1963-1965 with all of the bought in components replaced by bespoke Chaparral designed and built items as the performance envelope of the machine increased not least because of advances in polymer chemistry as applied to racing tyres- Chaparral’s ongoing testing of Firestone products provided plenty of valuable input in that regard. Brakes were Chaparral made cast iron solid discs clasped by Girling calipers front and rear.

The wheels were also bespoke, the development of which was first required to get brake temperatures down, the Chaparral spoke-like web structure wheels were strong, light and had a 1.5 inch advantage to the inner-wheel path through which heat radiated. Other advantages were that the bead depression or drop centre, necessary in ordinary wheels to get the bead over the rim flanges was neatly eliminated by making the outer rim flange detachable from the main wheel body- the absence of the depression provided an extra inch and a half on the inside diameter. A further advantage is that the same wheel body was used front and rear, as only the outer rim flange has to be changed to produce a wider rear rim.

See the sequence of photographs below, mainly taken over the Nassau Trophy weekend late each year, from 1961 to 1965 to see the rate of Chaparral technological progress from using someone else’s front-engined chassis in 1960 technological tour de force by 1965, make that 1963!

Jim Hall, aboard the Troutman & Barnes built Chaparral 1 Chev Nassau 1961 (D Friedman)

 

Jim Hall’s brand new Chaparral 2A Chev upon debut during the 1963 LA Times GP 13 October weekend- pole and led until an electrical fire intervened (D Friedman)

 

Jim Hall, Chaparral 2A Chev and AJ Foyt Scarab Mk4 Chev Nassau 1963 (D Friedman)

 

Hap Sharp Chaparral 2A Chev Nassau 1964 (E d Faille)

 

Jim Hall, Chaparral 2C Chev, Nassau 1965 (unattributed)

Together with the car’s chassis, the Chaparral bodies are of great interest given how visibly they were at the forefront of automotive aerodynamics of the time.

The original 1963 body was based on some Chevrolet wind tunnel data but when tested at Midland the car became very light at 120mph which gave rise to the ‘snow-plough’ air dams first used at Riverside in 1963 and very evident in the Nassau 1963 shot- this solution, Chaparral  were the first to do it, was the result of ‘fooling around’ with test track fixes. The team found the approach worked well on smooth surfaces with a ground clearance of circa 2.5 inches from the ground.

The first major redesign of the body was a new front end which solved one problem but gave rise to rear end lift, the solution to which was a vertical lip attached to the rear of the car- a spoiler, it was not an original solution having been first deployed by Ferrari at Sebring in 1961.

As speeds continued to increase more front end lift occurred which was countered by the small  appendages shown in many of the accompanying photographs low on nose of the cars on each side- these were first fitted to Hap’s car at Riverside in May 1965- they grew at Mosport a month later into ‘cowcatchers’ of the type seen on steam-locos! These vanes or trim-tabs remained. The rear of the car evolved as well, often in fine detail, with the 2C eliminating the high ducts on the flanks for engine compartment cooling which was discovered were not required.

Hall’s #66 2C alongside Sharp’s upgraded 2A at Nassau in 1965. Note the size and pivot for the ‘flipper’  aerofoil, what would later be described as a wing- the mounts either side are ‘fences’ to guide the airflow where it was required. Bob Bondurant’s Lola T70 is just in shot (A Bochroch)

 

2A cockpit during the USRRC weekend at Riverside in May 1965- 2 speed ‘box (D Friedman)

The movable spoiler or ‘flipper’ attracted plenty of attention at the time- it was introduced on Jim’s new 2C and fitted to Hap’s 2A- the aerofoil was mounted between two fins either side of the car, the angle of which was pivoted by the action of the a pedal using the drivers (available) left foot. On the straights it was flat- parallel to the cars body, in corners inclined. An extra master cylinder, a small pedal to the left and a hydraulic piston comprised the actuating mechanism. The default setting was of course the safe one- ‘up’, to exert maximum downforce.

So equipped, the 2C won its first race but Jim was  bothered by the deterioration in road holding caused by the much stiffer springs needed to resist the high levels of downforce generated- a case of solving one problem and causing another! Over that Winter of 1965-6 he and his engineer friends at Chevrolet worked out a way to mount the wings directly to the rear suspension uprights thereby bypassing a sprung chassis and permitting a return to ‘more supple’ springs- the dramatic 2E.

At the time the aerodynamics of very fast cars travelling over 150mph was limited, Hall wryly observed ‘…very few people know much about automobile aerodynamics, especially in the 150-200mph range but have strong opinions because they held their hand out the window of the family car once’! Wind tunnel tests provided some information but didn’t then reproduce what is happening under the car. In a tunnel there was no relative speed between the cars underside and the road surface and the wheels were usually not turning in an aerodynamic test. Hall operated on the basis of data obtained from tests at Rattlesnake…all of this is somewhat prophetic given the short period of five years which was to elapse from the time of this 1965 interview with Jim Hall and the 1969 developed 1970 raced staggering, revolutionary 2J Chev ground effect ‘Sucker’ Vic Elford and Jackie Stewart raced in the 1970 Can-Am.

Vic Elford in front of one of the McLaren M8D Chevs at Laguna Seca in 1970, Chaparral 2J Chev, a package with bristles with innovation and original thinking from every pore (Getty)

When discussing most Can-Am cars of the period much of the narrative is around the engines used given the chassis and aerodynamics of most of the customer cars at least, were ‘pretty similar’- not so with the Chaparrals given the chassis (sometimes), ‘automatic’ transmission and aerodynamics where the ubiquitous Chev engines were secondary but of course whilst they were Chevs, they were trick ones…

At the time it was said ‘Chaparral are having less Chevrolet engine trouble than anybody else’s cars’- Sharp and Hall attributed that to their engines being more nearly stock than any of the others! Mind you they were using aluminium blocks and heads ‘the result of happy circumstances in which Alcoa salesman (at the time) Roger Penske) talked Chevrolet Division into getting hold of the tooling originally intended for Gran Sport Corvette use’. By doing so they saved about 110 pounds over the cast iron engine, but the aluminium block limited them to the stock bore, hence they ran at a capacity of 327cid.

Interestingly and logically since adopting the ‘auto tranny’, the engines were tweaked for a wide spread of torque rather than for outright power- ‘the transmission does not allow nearly constant engine speed to be maintained over a large band of road speeds and because it has only one stepped gear reduction there isn’t a chance to keep the engine in a narrow speed band by changing gears often.’

Hall and Sharp said the engines used many standard parts- handy as they had just bought the Midland Chev Dealership at the time! Pistons were standard but for a stress relieving hole drilled at each end of the slot in the oil-ring groove to stop cracks. Also stock were the crank, main bearings and rods with all reciprocating parts sized, balanced and very carefully assembled. At the time the engines were good for circa 415bhp @ 6800rpm and 380 pounds/foot of torque @ 5200rpm. Proposed for 1966 was a shift to 58mm Webers from the 48s then used. The 327cid Chev designed aluminium V8, or 5360cc if you like, had a 4/3.25 inch bore/stroke, Chaparral modified it used a compression ratio of 10:1, Bosch ignition and four Weber 146 HCF 5 carburettors

With the constant evolution of the three 2s (it’s only in more recent times the 2A appellation has been applied) they gradually porked up a bit in weight- but getting faster in the process and ‘nicer to drive’ as Hall put it. They decided upon an aluminium chassis for the 2C to get the weight down albeit the chassis ‘was of the same basic design’- as a consequence the ally tub was 70 pounds lighter than the fibreglass ones and the overall all up car weight of the car 100 pounds lighter.

Interesting at the time- as subsequent events proved neither Hall or Sharp were ‘completely sold on aluminium yet’ raising concerns about the crash safety merits of the two materials observing an accident would inevitably destroy the whole aluminium frame whereas a ‘plastic one can be repaired by bonding in new pieces’ but Hall didn’t profess to know about what was safe and what was not in an accident.

The sportscars.tv article concludes ‘…this then is a brief summary of development to date. Central to the story is the fact that the car has remained adequately fast for two years instead of the usual one. No really drastic changes have been made, but the evolutionary process has been such that today’s Chaparral 2C doesn’t look that much like that original 2.’

‘When the first 2C appeared at Kent, Washington in September 1965 there was anticipation that the new car would be revolutionary whereas the 2C ‘really isn’t the new car but a refinement of the 2 but gets the C suffix as its builders thought the changes were significant enough to warrant that descriptor.’

The central body of the 2C is lower than the 2, the guards are of the same height. The body width was cut by six inches, the front and rear suspension geometry was modified a tad for more anti-dive, lift and squat. ‘A total of 100 pounds has been saved by the use of the aluminium chassis, and all the latest body revisions are incorporated, but it is not nearly as significant as will be the Chaparral 3 when it appears though we make no pretence of knowing when that will be…’ the author wrote.

Perhaps this is the revolution referred to above!- at least the 1966 one anyway. Jim Hall’s patent application drawing for ‘Aerodynamic spoiler for automotive vehicles’ of 15 July 1969 to protect the intellectual property expressed in the 1966 Chaparral 2E Chev. Note the names of the designers- Jim, Jerry Mrlik, James Musser and Frank Winchell.

Chaparral 2A mechanicals…

(D Friedman)

(D Friedman)

The bunch of shots above are of the Chaparral 2A #001 during its first race meeting- the 1963 LA Times GP 200 miler at Riverside over the 13 October 1963 weekend.

Tests at Midland in this chassis with a Buick engine initially, and then the Chev have already resulted in the spoilers at the front to keep the car on the ground. The new machine started from pole and was leading when retired.

(D Friedman)

Nice shot showing the overall layout of the car and big, strong fibreglass chassis, plenty of interest from the punters not least John Surtees at right thinking ‘How am I going to explain a plastic car on pole to Enzo?’.

(D Friedman)

Mickey Thompson and Jim. Happy with the speed of their steed no doubt.

(D Friedman)

Notice the way the chassis goes all the way to the back of the car to support the engine and Colotti Type 37 4-speed gearbox, suspension Lotus based inclusive of uprights and wheels at this stage.

Front suspension from above as per text- upper and lower wishbones and coil spring/dampers. Steering rack is Cooper, fuel tank filler open, again note the chassis.

(D Friedman)

 

(D Friedman)

Rear suspension detail, note the spare wheel- Lotus ‘Wobbly-Webs’.

(D Friedman)

That front end is savage on the eye, data from Chev upon which it was based fell short- the radical front spoilers were a fix improved upon by the first new nose shown throughout this article. Nice cockpit shot and aluminium Chev small block.

(K Breslauer)

Final shot of 2A #001 in its earliest form is a month and a bit later in the December 1963 Nassau Oakes Field paddock.

 

(E d Faille)

Franz Weis sets to on Roger Penske’s 2A at Nassau in 1964.

Jim and Sandy Hall are there too, this is a post race shot where the cars suspension is being repaired in-situ. Penske took over Sharp’s car during the mandatory pitstop and they shared the win. Note the spoiler is inserted into a slot in the tail, located by fasteners.

(A Bochroch)

With Jim Hall’s arm in a cast Penske drove the second team car at Nassau- here in the course of pre-event preparation, Roger slipped off the track in the rain- breaking the car’s suspension- thanks to Hap’s generosity Roger shared the win. Notice the fibreglass chassis, ‘stack pipes’ and wheels.

 

(A Bochroch)

2A, same theme in the Sebring pits in 1965 before Jim and Hap go out and whip all the big guys. Hall is on his iPhone by the wall amongst the spare wheels- they raced two cars that weekend.

Note in particular the ‘plastic fantastic’ full monocoque chassis, of which we get a really good gander- it goes right to the back of the car to which everything is affixed, none of yer load bearing engines et al here.

Big steering wheel, small light above the roundel to illuminate number 3, inspection/access cover open below the coolant top tank, lotsa pipes- both inlet (Weber carbs) and outlet, big cast iron disc and that GM automatic transmission covered out of secrecy or fun…Marvellous, the more you look, the more you see.

 

(K Ludvigsen)

Hap Sharp’s 2A in the Riverside paddock, LA Times GP meeting in October 1965.

You can do your own compare and contrasts over the ensuing twelve months from Nassau in late 1964 but the front winglets, copious venting of the guards to allow trapped air to escape and plenty more rubber on the road are obvious.

(B Tronolone)

Nice shot of Hap Sharp with Jim Hall behind him, again at Riverside in October 1965.

Note the front winglets on Haps 2A and Jim’s 2C but the absence of the guard venting on the latest 2C compared with the earlier car. Hap’s also has the huge vent taking lotsa air into the cockpit which I guess is a driver preference thing. These close-up shots are gold really if yer get yer rocks off on this kinda minutae…

Chaparral 2C mechanicals…

(B Tronolone)

Jim Hall and his new 2C in the Riverside pitlane in October 1965.

Bob Tronolone took the shot above of Hap and then walked a few metres and captured Jim.

So the compare and contrast is of Hap’s ‘ultimate spec’ 2A and Jim’s new 2C- the chassis are different, bodywork similar, noting the comments above about the front guards- both machines are fitted with the movable rear ‘flipper’.

(E d Faille)

2C Nassau 1965 butt shot above and then this splendid ‘in all of its naked glory’ photograph again at Nassau below.

These big-block American iron are such enormous, heavy muvvas one gets a very clear sense of the packaging challenge. It doesn’t matter how low you can mount the thing in your you-beaut monocoque, 327cid of V8 still sits in the air like a country-long drop dunny!- mind you, half the height is inlet manifolds and carbs.

I think of these wheels as archetypal Chaparral! What a gorgeous but brutal instrument of war- during the race the right front suspension failed, the car left the course damaging the rear suspension and tub as well. The latter wasn’t too bad though being rebuilt as the first 2E- tagged 2E-001.

(E d Faille)

 

Jim aboard the 2C at Riverside in October 1965 during the LA Times GP 200 mile race.

Etcetera…

In the best of clever racing tradition, making use of what you have- and what still works the mix ‘n match of Chaparral 2 chassis is as follows;

#2A-001 reconstructed into 2D-001

#2A-002 reconstructed as 2D-002 (1966 endurance coupe), then 2F-001 (1967 endurance coupe) and ultimately restored as it began- 2A-002, no doubt some of you lucky folks have been thru the Chaparral Museum

#2A-003 reconstructed into 2F-002

#2A-004 chassis unused

#2C-001 reconstructed into 2E-001 (1966 Can-Am car) then later used as 2G (1967 Can-Am car) and restored as 2E

#2E-002 destroyed in Jim Hall’s accident 1966

#2H restored as was, 1969 ‘unloved by John Surtees’ Can-Am car

#2J restored  as was, 1970 Can-Am ‘Sucker-Car’

#2K 1980 Indy winner restored as such

(Getty)

Superb looking racing car- 2C Chev in the LA Times GP Riverside pitlane in 1965.

Bibliography…

‘Can-Am’ Pete Lyons, sportscars.tv article ‘Chaparral 2C – Work Leading To’

Photo Credits…

Getty Images- Eric Rickman, Toby Palmieri, John Christy, T&E Fornander, David Friedman Collection, gtplanet.net, chaparral.com, Eric della Faille, Albert R Bochroch, William Hewitt, Nigel Smuckatelli, Karl Ludvigsen, Kenneth Breslauer

Tailpiece: 

Oh for a future of substance for Chaparral…

Finito…

Chapp

Fabulous shot of the Mike Spence/Phil Hill Chaparral 2F Chev at La Source hairpin, Spa-Francorchamps, May ’67. 

The cars automatic gearbox failed in a race won by the Ickx/Thompson/Rees Mirage M1 Ford. 1967 was the last year of the 7 litre ‘monsters’, the CSI mandated a 5 litre limit from ’68.

Ford started the ’67 season with their new Ford GT MkIV and then left the scene having won Le Mans twice on the trot, ‘mission accomplished’ in a sense. Ferrari won the championship from Porsche by 2 points in a season of grids comprising Ferrari P3/4, Porsche 910, Lola T70 , Ford GT40’s , Alfa Romeo T33 , Mirage M1 and Matra M630…truly a Sports Car Season to savour.

le mans 67 start

As Mike Spence buckles up his seatbelt in the Chaparral 2F Chev, second on the grid, he is surrounded by FoMoCo vehicles; #1 the victorious Gurney/Foyt, #3 Bianchi/Andretti and Hulme/Ruby Mk4’s, and the #5 Gardner/McCluskey and Schlesser/Ligier Mk2’s…not a Ferrari close by! (Unattributed)

The 2F was consistently quick throughout the season but often the transmission main drive-bearing failed. Both Hill and Spence were popular Chaparral team members. Of Hill, Jim Hall said ‘Phil was a great guy with a lot of talent and really fun to work with because he understood a lot of what was going on.’

‘I think he was probably as good as anybody at making the car finish. He’d put many cars together himself and knew how everything was made and how to take care of it. He was a great endurance driver for other reasons, but for that reason too. When we got near the CanAm season in 1966 we decided we’d offer Phil a drive. He was a great guy to have on your team – he pulled for you and worked for you. And in the endurance races he was our man. I think Phil enjoyed driving for us, we just had a good relationship.

Phil Hill never raced again after his ’67 Brands 6 Hour victory, a great way to bow out after such a career of achievement. ‘It was absolutely satisfying to win that race at Brands Hatch…in retrospect there couldn’t be a better way to finish a career could there?’ he said. The 1967 Endurance Season is covered in full in this recent article on the Ferrari P4…https://primotipo.com/2015/04/02/ferrari-p4canam-350-0858/

phil hill

Phil Hill pondering 2F transmission dramas at Le Mans 1967. Mike Spence sans helmet behind him. (Dave Friedman)

Hall also had great respect for Spence who was killed at Indianapolis in May 1968 in a Lotus 56. ‘I really thought a lot of Mike. He was an awfully talented driver, very quick and a smart guy who worked hard. He was a good fit for Chaparral too. It takes the right kind of person to be on your team who fits in with your people and how they work and Mike fitted us well and was a joy to work with’.

Designer/Driver/Engineer Jim Hall’s cars bristled with innovation; the winged, 7 litre Chevrolet engined, fibreglass monocoque, auto ‘tranny Chaparrals’ thrilled European spectatators and finally won a ’67 race, the Brands Hatch 6 Hour event in July before returning to their Midland, Texas base and the US CanAm Championship from whence they came…

chapp spa

2F at rest, Spa pits 1967. Hill talks about set-up with Jim Hall. Note the front lip or splitter. Spence put the car on pole at 3:31:5, quick enough for 6th on the GP grid that June…in a car designed for 24 hour events. OK its 7 litres, but remarkable all the same. (Unattributed)

Innovative Chaparral 2F…

The 2F was a massive departure from previous Chaparrals’ even by their standards.

chap 2f aero

This drawing neatly shows the Chap 2F key aero elements; cars shape, front spring loaded flap, you can just see the chin lip spoiler used on some tracks at the front. Rear mounted rads and beautiful ducting in and out and the movable high rear wing, to alter between download and neutral positions. (Unattributed)

The car featured hip mounted radiators to better position weight and had the bi-product of keeping the cockpit cooler. The 5 year old 2A chassis had special mouldings bonded to it to create the square sided shape, the transformations were such that they were effectively new. To provide strength to the bodywork, sections were laid up in female moulds with 4-oz cloth and epoxy resin and ¼ in PVC foam. In areas were strength wasn’t required the fibreglass was very thin. Firestone developed wider tyres for ’67 which required wider bodywork, the actual chassis was covered by flat panels on either side, these were ‘skins’ with empty space between them and the old chassis.

Externally only the central cab section looked the same. A new body profile was evolved in the form of a wedge to generate downforce. At the rear the body tapered away to a ‘spindle shape’ with a ‘chopped off tail’.

To balance downforce at the front a similar type of high mounted wing as was used on the ’66 2E CanAm car was used, mounted directly to the rear uprights. The wing was connected to a foot pedal and via hydraulics allowed the driver to have feathered ‘lo drag’ or maximum downforce modes. Should anything go wrong with the feathering mechanism or the driver needed his left foot for the brakes, the car went to fail safe maximum downforce, understeer mode.

The front opening contained a spring-loaded flap or duct that opened against air pressure when speeds exceeded 120mph, this helped balance aerodynamic loads front to rear.

The body floated free on its springs devoid of practically any downforce which was applied directly to the uprights by the monster rear wing. As the nose of the car pitched forward more front downforce was generated, at 150mph the nose compressed the front suspension, the trapdoor or flap opened progressively at 120-140mph, the car would then settle to its appropriate ride height front/rear.

2f naked at le mans

2F naked at LeMans for its transmission repair. Big wing and its mount direct to rear suspension uprights, note forward facing support strut. Mid mounted radiators, seat belt in the cockpit, radiator header tank, bell mouths of Chev/Weber carbs, spare wheel housing, exhaust ducting. ‘LeMans’ number lights, 12X16 inch Chap alloys and big, wide Firestones. (Albert Bochroch)

Chaparral modelled both aluminium Chev 327CID  and 427CID engines, with different car weight limits applicable under the regulations. They considered the existing CanAm aluminium chassis with 5 litre engine and a fibreglass chassis car with the bigger 7 litre ‘lump’. The 5.4 litre engine could have been ‘destroked’. Simulations showed the latest staggered valve ‘porcupine’ 7 litre Chev, cast in aluminium the faster option. It weighed 85 lbs more then the ‘smallblock’ but gave around 100bhp more. The engine used Weber style 58 IDM carburetors built by Chev and gave circa 575bhp @ 7500 rpm.

The Chaparral’s GM automatic transaxle was upgraded to three speeds but the ‘box was at its limits and the increased power and torque proved the gearbox was the packages weak link, this was feared by Chaparral from the start of the 2F program. GM simply did not want to build a new transmission and hoped internal changes could cope with the 7 litres’ greater torque, but this was not to be the case.

There is a lot of mystique about the transmission, Pete Lyons, in his ‘Profile Publications’ article on the Chaparral ‘Glassfibre Cars’ described it as follows ‘It was laid out much like a Hewland with 2 speeds and later 3 and an hydraulic coupling, a torque convertor instead of a clutch.’

‘The gears were simple straight cut spurs engaged by sliding dog clutches; every second dog was cut back a little to assist the clutchless changes. The changes were all done manually, the driver easing his throttle foot to unload the dogs and snatching the gear as quickly as he could. It therefore wasn’t really an automatic transmission, it was a fluid clutch transmission. The engine was always started with a gear engaged, the driver preventing a lunge foward by firm pressure with his left foot. At…5000rpm the coupling was designed to lock up rigidly to prevent further slip and power loss. Sensitive drivers could feel this happening’.

The advantages of the ‘box were better modulation of braking, on down changes the fluid coupling lessened any tendency of the rear wheels to lock, finally the fluid coupling absorbed many shock loads such as a ‘yump’ landing, common at the time.

2f

Superb James Allington cutaway of the 2F showing all of its innovations : fibre-glass monocoque, wing, automatic transmission, 7 litre aluminium block Chev…1967 remember. Simply superb innovative design and execution by Jim Hall and his Texas Team (James Allington)

Jim Hall’s attention to weight saving was fanatical, the car weighed 1750lbs wet, 600lbs less! than the Ford MkIV. This was due to the fibreglass chassis, aluminium rather than (Ford) iron block engine, the batteries were of very expensive cadmium from the aerospace industry. The body was made of a sandwich of 1/4 inch thick PVC foam between the thin skins of ‘4 oz cloth’ impregnated with Shell epoxy resin which was formed to shape in a vacuum bag apparatus and then cured at room temperature. Sylvania made new quartz iodide lights using hand made bulbs in Marchal reflectors.

The whole car was built to exceptionally high aerospace standards of quality and finish.

hall chap 2g

Jim Hall in his 1967 CanAm challenger, the Chaparral 2G Chev at Bridgehampton. DNF chassis failure. The McLaren M6 Chevs were dominant that year, Robin Herd, the M6 designer freely acknowledged the effect Halls’ designs, especially the 2E, the first car with the high wing had on him. Hulme won the race in his M6A. (Pete Lyons)

Jim Hall and Aerodynamics…

Gordon Kirby interviewed Jim Hall in 2008, he published these comments by Hall about his seminal aerodynamic work in the mid 60’s…’We calibrated the suspension by just rolling the car out and putting weights on it so we knew what load it took to move the car up and down. We had a cable drive that drove a pencil and a roll of paper that was run by a little motor so you could set your zero point. You would go out and make a run and push a button and make a mark across the paper so we knew what the front and rear downforce was. You could run a couple of different speeds and then you could put it on a graph. You knew that it was increasing as the square of the speed so you knew what the curve looked like and you pretty much had the downforce over a speed range. That was pretty simple to do.’

Hall’s method of measuring the air pressure or downforce on the surface of his car’s wings or bodywork was equally simple in concept. ‘The other thing we did was when we needed to change the surface we had a manometer that was just a bunch of u-tubes made out of tigon tubing and full of coloured water,’ Hall related. ‘If you were in a sports car you put it in the seat beside you and then went out and tapped a bunch of holes in the. You ran these to one side of the tubes and ran the other one to a pitot tube so you could get the dynamic air pressure on the surface.

I originally did it with a Polaroid camera. I had a Polaroid camera mounted on the dash and the manometer mounted on the seat back beside me. I didn’t even have a pitot tube for a static pressure source. I read in a book somewhere that a guy in WWI thought about doing this. The way he thought about doing it was you took a thermos bottle and put a piece of tubing in it and right before you made the test you opened it up then closed it so you had static air pressure in it. Then you went out to make your run and compared it to the pressures you got, then opened it and made sure it didn’t change.

‘In a matter of about twenty minutes that thermos bottle would maintain an even enough temperature that the pressure wouldn’t change much. So you had some static pressure while you were sitting in the pit and you also had static pressure when you were going down the straightaway. It’s simple-minded, but pretty tricky! And that’s the way we started.

‘Then we bought a light airplane pitot tube and mounted it out front of the car. We found a static pressure place where we could run that pitot tube that matched the thermos. Then we had a static pressure source all the time.’

Thus began the serious science of racing car aerodynamics. Of course, Hall had no idea about the depth of the pandora’s box he was opening but he is without doubt the father of the modern aerodynamically-driven racing car.

targa overhead

This overhead shot is of the 2F at Targa 1967, drivers Hill and Hap Sharp. The angle is interesting; you can see the contours of the car, radical for the time. Front flap exit above the number, mid-ships mounted rads and exit venting, the row of 3 circular vents in the rear panel to relieve air pressure and the ever present driver adjustable rear wing, max downforce for 90% of the time in Sicily i imagine. (Unattributed)

cahp le mans

Chaparral 2F Chev ‘butt shot’ in the Le Mans parc ferme. The radically different aerodynamic treatment in terms of both the cars shape and rear wing apparent. Road registered to boot…The car quailfied 2nd in the hands of Mike Spence and Phil Hill, they retired on lap 225 with transmission oil seal failure. The sister Jennings/Johnson 2F failed after 91 laps with starter and battery dramas. The race was won by the Gurney/Foyt Ford MkIV. (Unattributed)

bonnier chap 2 d

The 1967 Chaparral 2F’s predecessor in endurance racing was the 1966 2D, here in Jo Bonnier’s hands in the Karussel at the Nurburgring where he and Phil Hill won on the cars European debut. The 2D also used a fibreglass monocoque chassis, had a 2 rather than 3 speed box of the 2F and was powered by a Chev 327cid/5360cc ‘small block’ Chev giving circa 475 bhp @ 7000 rpm. Like the 2F, its race record was littered with DNF’s, 6 from 7 starts. (Unattributed)

Chaparral 2F: 8 Race History…

One of the things which strikes you about this big car when you look at its speed during 1967 is its pace on all types of circuits, it was on pole at Monza, Spa, and the Nurburgring, started from grid position 2 at Sebring and Le Mans and grid 3 at Brands.

The challenges of the Daytona bowl are vastly different to the swoops and curves of Targa or the ‘Ring let alone the high speed challenge of Le Mans. It was clearly a ‘complete car’, an excellent all around package, the best car Phil Hill was quoted as saying that he ever drove.

At Daytona the car ran with its wing fixed in position, but still only just missed pole. Hill lead, took the fastest race lap and was pulling away from the Ferrari P4’s until the fourth hour, falling off on marbles after a pitstop and hitting a wall. Hill was a little miffed that teammmate Mike Spence, with whom he had a great working relationship, had not warned him about the hazard, their race ended on lap 93, Bandini and Amon taking a Ferrari P4 win.

2 f sebring

Mike Spence here, and Jim Hall raced the 2F at Sebring. Fastest race lap but again DNF with ‘box troubles. (Nigel Smuckatelli)

At Sebring Hill was forced to retire from the meeting having acute appendicitis so Jim Hall stepped into the car with Spence, he was 2nd on the grid but had trouble starting. The car retired on lap 145 with differential failure, the car car trailed smoke for several laps in adavance of retirement, victory went to the Mclaren/Andretti Ford MkIV.

In Europe the cars were based in Frankfurt, the Monza event the first on the continent. Spence put the car on pole, using the second 2D chassis converted to 2F spec and from the flag diced with the P4’s but a universal joint failure eliminated the car before the end of the first hour. Bandini/Amon won in a P4.

At Spa a week later the car had a small trim tab added at the wings trailing edge, the tab made it easier to adjust the wings settings at high speed. Hill put the car on pole by 3.5 seconds but rain fell on Sunday, ‘Rainmaster’ and local boy Jacky Ickx ‘ate us alive’ Hill said. Spence ran in 5 th till a fuel stop after which the car refused to start. At half distance it was 8th but another blown transmission seal caused its retirement. Ickx and Thomson won in a Mirage M1.

2 f targa

Phil Hill in his ‘outta this world’ futuristic Chaparral justaposed with the ancient Sicilian landscape…and the oh-so-conventional, if gorgeous Ferrari P4’s for that matter. But Porsche prevailed, as they so often did at Targa. (Yves Debraine)

Mike Spence had other commitments so Hap Sharp stepped in with Phil Hill at the Little Madonie, the 575 bhp ‘roller skate’ a challenge around the mountainside of the famous Targa course. Local boy Nino Vaccarella was faster in practice than the 2F by 1.5 minutes, the car not entirely happy over the bumps but was still up to 4th, 9.5 minutes behind the leading Porsche when a tyre went flat at Collesano. Paul Hawkins and Rolf Stommelen took the win in a factory Porsche 910.

targa 2f

Lookout! Phlegmatic Siciliani…Targa 1967. Ride height up for this event, front splitter replete with an empty pasta packet clear. Phil Hill/ Hap Sharp Chap 2F. (Unattributed)

At the ‘Ring Spence took 5 seconds from the old sportscar lap record and set the first over 100mph lap by a sporty, John Surtees was 7 seconds adrift in his Lola T70. Hill put on his harness after the Le Mans start so came around in 6th, by lap 8 he moved into the lead, but at about the 1.5 hour mark, on lap 10, the cars transmission again failed. Schutz/Buzzeta won in a Porsche 910.

chap 2f nurburgring

Phil Hill is back in the pack on lap 1 of the Nurburgring 1000Km, having carefully put on his ‘belt. Amongst the class cars are a Ford GT40 in front of him, you can also see the nose of the Surtees/David Hobbs Lola T70Mk3 Aston Martin behind and to the side, DNF with rear suspension failure. That wing will have given cars being pursued no doubt as to the car behind! (Automobile Year)

Le Mans was and still is all important, 2 cars ran, Hill/Spence missing pole by only 0.3 of a second from a Ford MkIV. Johnson/Jennings in the other car were 24th. Both 2F’s got away well, by the end of the first hour Spence was 4th and by the second he was 2nd, then the wing actuation broke, the car went into high downforce safe mode knocking around 40 mph off the top speed.

Inevitably the transmsision gave trouble but the car was still in 3rd when an heroic 3 hour rebuild of the transmission was commenced by the crew, all to no avail as the car was withdrawn. The other 2F retired earlier with ‘electrical failure’. The race was famously won by the All American Boys, AJ Foyt and Dan Gurney in a Ford MkIV.

le mans rebuild

The long 3 hour, crowd pleasing, crowd appreciating transmission rebuild is underway. LeMans 1967. Franz Weis and Karl Schmid start the process by stripping the rear of the car to gain ‘box access, no mean feat in itself given the careful integration of the overall package. (Karl Ludvigsen)

The inaugural Brands Hatch 500 Miles was the last championship race of the season, the Brabham/Hulme LolaT70 on pole, Spence/Hill 0.8 second adrift in 3rd. Hulme took the lead but retired with rocker failure, letting the 2F into the lead. A long mid race pitstop dropped them back to 3rd but consistent laps of taking 2 seconds per lap from the Ferrari in front saw the wonderful car displace the Stewart/Amon Ferrari P4. A winner, finally!

Motor racing is full of ‘ifs, buts and maybes’.

As the great, late and laconic Frank Gardner said ‘If Yer Aunty had Balls She’d be Yer Uncle’…but one wonders what this seminal, defining, brilliant car would have achieved had the ‘oh so clever’ ‘automatic gearbox’ which was such a big part of most of the Chaparral 2 program, had the re-engineered gearbox it so badly needed and deserved?!

In a sad sequel Jim Hall was preparing for another season with a 7 litre car for 1968 when the FIA announced a 3 litre limit for prototypes from 1968 and limited sports cars to 5 litres in capacity, 25 examples of which had to be built for homologation. The big Fords’ and Chaparrals’ were out, racing the poorer for it.

It was not over for Chaparral of course but after 1967 they focused on their domestic CanAm Championship with equally radical cars, and many years later a victorious assault on the Indy 500, both stories for another time.

chap 2 hill brands

Mike Spence in the 2F at Brands Hatch headingfor victory and running ahead of the factory Ferrari P4 of Ludovico Scarfiotti and Peter Sutcliffe, 5th. (Louis Klemantaski)

Tailpiece…

chap 2 j riverside

Its hard to know which of Jim Hall’s cars was the wildest, perhaps the ’69 CanAm 2H, a very unsuccessful one i will write about soon. He doubled his bets with the 1970 2J, the famous ‘ground effect sucker’ car being so quick officialdom banned it and with it the whole ethos that made the CanAm the great ‘Formula Libre’ Series that it was. Here at Riverside, sportscar ace Vic Elford in the 2J Chev leads Peter Gethin in the championship winning McLaren M8D Chev. Hulme won the race in the other M8D, Gethin DNF engine on lap 21 and Elford DNF engine on lap2. (Unattributed)

Etcetera…

jim and phil

Jim Hall, left and Phil Hill CanAm 1966. (Unattributed)

chap drawings

Chaparral 2F drawing, car depicted as it raced at Targa 1967. (Unattributed)

sebring engine change

Sebring engine change showing the girth of the aluminium 7 litre ‘big block’ Chev and the housing of the famous GM ‘automatic’ transaxle. I wonder how long the change it took from start to finish? (Unattributed)

targa butt shot

Targa 2F butt shot, aero treatment of the car nicely contrasts with the Sicilian ‘roadies’. Wing in maximum downforce mode. Note the rear devoid of tail panel, compared with the earlier LeMans rear shot. (Bernard Cahier)

 

hill aviating

Phil Hill aviating the 2F at the Nurburgring despite the Chaparral wing in full downforce mode! Lightening fast, the 1000Km  another race the car should have won on a circuit one would not necessarily have thought it were suited. A versatile car the 2F, quick pretty much everywhere. (Unattributed)

cahap family tree

The ‘Chaparral Family Tree’…(Unattributed)

Credits… 

Pete Lyons ‘The Chaparral 2,2D,2F The Glassfibre Series’ Profile Publications, Cutaway drawing- James Allington, Jim Hall quotes from a Gordon Kirby ‘MotorSport’ articles in November 2008 and January 2011, Dave Friedman, Bill Wagenblatt ‘Track Thoughts’, Albert Bochroch, Nigel Smuckatelli, Karl Ludvigsen, Bernard Cahier, Louis Klemantaski

See this link for some great information on Jim Halls fabulous cars…

http://www.thechaparralfiles.com/

Finito…