Gurney-Weslake Ford V8…

Posted: June 14, 2018 in F1, Sports Racers
Tags: , ,

(TEN)

Dan Gurney’s Lola T70 Ford during the Stardust Grand Prix, Las Vegas Can Am round, 13 November 1966…

Gurney didn’t have a great weekend, the fuel injected Gurney Weslake aluminium headed Lola qualified eighth and failed to finish with a fuel tank breather problem. John Surtees won the race and the series in a Lola T70 Mk2 Chev. The photo got me thinkin’ about those cylinder heads…

AAR Lola T70 Gurney Weslake Ford V8, Las Vegas 1966 (D Friedman)

Dan from Phil Hill, Chaparral 2E Chev, Las Vegas 1966 (D Friedman)

As above, ditto Gurney below (D Friedman)

The Gurney-Weslake combination is best known for the Formula 1 60 degree, DOHC, four valve, Lucas injected V12 which was fitted into the gorgeous Eagle Mk1 created by Len Terry and Dan in 1966- initially fitted with a Coventry Climax 2.7 litre ‘Indy’ FPF four cylinder engine, the V12 finally raced at Monza in 1966 and won its only GP, at Spa in mid 1967. But the F1 project resulted from the relationship which arose from the development of special cylinder heads for the pushrod small-block Ford V8 a little earlier.

Gurney’s Belgian GP victory, Spa 1967. Surely one of the 5 best looking GP cars ever? Eagle Mk1 Weslake chassis ‘104’- path to the F1 relationship between Dan and the Weslake concern was via the Ford V8 program which preceded it (unattributed)

Len Terry designed Eagle Mk1 powered by Gurney-Weslake V12, 1966. Cutaway by Bill Bennett

Gurney was keen to better exploit the performance potential of the small-block 289 cid Ford V8 with which he was so familiar from his AC Shelby Cobra, Ford GT40 and Can Am experiences.

This engine family was the same as that which provided the first 255 cid pushrod engines used by Team Lotus at Indy in the rear of Lotus 29’s raced by Dan and Jim Clark in 1963. Whilst Dan’s plan was initially to get more competitive engines for the Sports Car Club of America’s burgeoning sportscar races, which would of course become the Can-Am Championship from 1966, the Gurney-Weslake V8 engines ultimately won the 24 Hours of Le Mans and races in Group 7 sportscars and Indycar single-seater categories and beyond.

Dan had seen what Keith Duckworth had done with pushrod Ford engines in the UK- 100 bhp per litre, and figured the same approach could be successfully applied to the Ford V8.

‘I heard that Duckworth had modified a four-cylinder Ford Anglia cylinder head by boring an inlet tract hole straight at the port, so it was a more direct shot and I believe that was the first time that a little four-cylinder 1000cc pushrod engine made 100 horsepower. It seemed to me to be a pretty neat thing to accomplish and, naturally, being inquisitive, I wondered if the same idea could be applied to a Ford V8, since it looked to me as though we could do something similar to the 289-302 style engine’.

‘Actually we began our inquest with an extensive rework of the existing 271 bhp heads. At the peak of our testing with the 271 hp cast iron heads on a 325 inch block, we were pulling as much as 448 hp on gasoline. It was about this time we figured a few improvements along the lines of a new head design might give us even more power, so we got after it’.

Dan sought out Weslake Engineering just outside Rye near the East Sussex coast of England and via Production Manager Michael Daniel engaged them to do some drawings after Gurney delivered some 289 heads to be inspected, analysed and sectioned.

Harry Weslake in his factory in April 1968 with a Read-Weslake 500cc GP motorcycle engine (S Sherman)

Patterns were made and these first ‘Mark 1’ Gurney-Weslake heads were cast at Alcoa Aluminium’s foundry in Pennysylvania.

They featured circular inlet ports that provided a direct path from manifold interface to valve seat in order to get as much fuel-air mixture as possible into the combustion chambers. The valves were inclined at 9 degrees to the cylinder centreline instead of the 20 degree angle of the stock Ford heads. The valve guides were fitted with Perfect Circle teflon valve seals. Classic Weslake combustion chamber shapes were deployed- heart shaped with precision machined valve seat inserts- steel for the inlets and bronze for the exhausts, both press-fits into the heads.

Early G-W Ford on 48 IDA Webers- ‘DG asked Weslake & Co to reate a cylinder head…that provided a direct pathway for the fuel mixture from carburettor to inlet valve, as can be seen from this head-on view…’ (AAR)

Front view shows the ‘standard’ Ford block and drives, oil filter, distributor, 48 IDA downdraft two-barrel Webers, ally heads (AAR)

An immediate improvement of 70-100 bhp was achieved over the standard 289-302 heads both through the mid to upper rpm ranges without losing smoothness down low. To cope with the increased loadings the bottom end also ‘had a birthday’ with bits and pieces provided by well known suppliers of US performance gear.

The Dearborn Crankshaft Corporation made a steel crank to AAR specifications which sat in bearings donated by the Ford DOHC Indy motor. Carrillo provided shot-peened conrods to which were attached Forged True pistons- compression ratios ranged from 10.5 to 11.6 to one. Jack Engle worked on cam grinds arriving at solutions which involved short lift and long duration with ‘rev springs’ fitted into the block’s oil galleries to assist the proper seating of the valves at high rpm. Ford’s stock high pressure oil pump was man enough for the job with stock oil pans baffled and main bearing girdles added to keep the whole lot stabile.

Times GP Riverside, McLaren Elva Mk1 Ford G-W, 1965 (TEN)

The Gurney-Weslake heads were first used by Dan during the 200 mile LA Times Grand Prix sportscar race at Riverside in late October 1965 fitted to his McLaren Elva Mk1

In an all-star cast which included Jim Clark, Bruce McLaren, Chris Amon, Hap Sharp, John Cannon, Peter Revson, Chuck Parsons, Jerry Titus, David Hobbs, Bob Bondurant, Parnelli Jones, Richie Ginther, Graham Hill, Jerry Grant, Walt Hansgen, and Dan (wow!- was there ever a better ‘Can-Am’ field of depth)- that race was won by Sharp’s Chaparral 2A Chev from Clark’s Lotus 40 Ford and McLaren’s McLaren Elva Mk2 Olds. Dan’s AAR McLaren was out with brake troubles on lap 24. By that stage of G-W development Mark 2 heads were fitted which incorporated improvements including removable rocker arm studs.

Monterey GP weekend, Laguna Seca October.1966. DNF lap 4 with an undisclosed ailment, Lola T70 Ford with Mk 3 G-W heads- note still on 48 IDA Weber carbs (D Friedman)

 

Laguna 1966. By this meeting the G-W engine developed 520 bhp and 415 lb ft of torque @ 6300 rpm (D Friedman)

 

Hmmm, too short a race- Laguna 1966, Lola T70 Ford DNF after 4 laps from Q4- behind the 1st and 2nd placed Chaparral 2E Chevs of Phil Hill and Jim Hall and 3rd placed Bruce McLaren’s McLaren M1B Chev (D Friedman)

‘Mark 3’ Gurney Weslake heads were developed in 1966 with alterations to make assembly and maintenance easier.

With this configuration AAR took their first GW head win in the May 1966 United States Road Racing Championship round at Bridghampton- Jerry Grant won in the AAR Lola T70 Ford from Lothar Motschenbacher’s McLaren Elva Mk2 Olds and Mike Goth in a McLaren Chev.

The same chassis was used by Dan to win the Long Island, Bridghampton Can-Am round in September 1966- in a splendid weekend for All American Racers Dan popped the Lola T70 Mk2 on pole and won from the works McLaren M1B Chevs of McLaren and Amon. Sadly, it was the only Can-Am win for a Ford powered car. 495 bhp @ 7800 rpm was claimed at the time ‘The redline used to be 8000 rpm but I just found I could turn 8900’ Dan quipped after the race.

Its interesting to look at the engine competition at the time. Pete Lyons in his bible ‘Can-Am’ writes ‘Chevrolet’s small block was the typical T70 engine of 1966, and those offered by well respected Traco Engineering in Los Angeles can be considered definitive. The bore remained standard at 4.0in but a stroker crank of 3.625in gave a displacement of 364.4 cid. Breathing thorough a quartet of two-barrel 58mm Weber side-draft carburettors…such a package was rated at about 490bhp at 6800 rpm and 465 lb ft of torque at 4500…it weighed about 540-560 lbs. Price was just under $US5000’.

Rindt’s Eagle Mk2 G-W Ford on the Indy weighbridge in May 1967, sex on wheels (D Friedman)

 

Len Terry’s Eagle Mk1 design was a bit of a pork chop in F1- designed as it was for both GP and USAC (Mk2 50 pounds heavier than its F1 brother) use. The design drew heavily on his previous Lotus work and is a beautiful, in every respect, expression of monocoque orthodoxy of the day in both chassis and suspension (D Friedman)

Towards the end of 1966 the engine was also fitted to the very first Eagle Indycar chassis- Mk2 ‘201’ which was raced by Dan in the ’66 Indy with a Ford 255cid DOHC motor- in fact Gurney didn’t complete a lap having been wiped out with eleven other cars in THAT famous collision. In the re-engined Ford G-W 305 cid powered car Jochen Rindt contested the 1967 Indy 500- he qualified 32nd and retired after completing 108 of the 200 laps with valve trouble- classified 24th. His was the only 305 cid ‘stock block’ powered car in the field, the race won by AJ Foyt Coyote Ford from Al Unser and Joe Leonard in Ford engined Lola and Coyote respectively.

‘chewin the fat- lots of downtime for drivers during the month of May at Indy- youthful Amon, Hulme and Rindt in 1967. Dude on the left folks? (D Friedman)

Eagle Mk2 ‘201’. Hilborn injected G-W V8, metering unit between body cowl and injection trumpets, quality of build and finish superb. Note beautiful body cowl and nerf bar (D Friedman)

Further development work resulted in the ‘Mark 4’ variant which was lighter in weight with narrower rocker covers and an intake manifold inclined towards the engines centreline.

Into 1967 AAR’s Can-Am engine was based on Ford’s new ‘mid-sized’ block stroked to 377cid- Dan’s Lola T70 was often the best of the ‘non-McLaren M6 Chev’ class in a year of dominance from the Kiwi’s with their beautiful papaya cars. Pole at Riverside was a standout.

Fitted with a Mark 4 engine, but 318 cid, gave Dan and the G-W engine’s first USAC win in the Rex Mays 300 at Riverside in November 1967. His Eagle Mk3 won from pole from the Bobby Unser Eagle Mk3 Ford ‘Indy’ V8 and Mario Andretti’s Brawner Ford on the challenging 2.6 mile California road course. Gurney achieved six more USAC Championship wins over the next two years and finished second twice on the trot at Indy in 1968 in a Mk3 and in 1969 in a Mk7 ‘Santa Ana’.

Changes to USAC rules for stock-block engines ultimately allowed the G-W motors to displace 318 cid- on methanol they were good for 560 bhp @ 7500 rpm in 1968 with circa 600 in 1969. On petrol a sprint 289 was good for as much as 506 bhp @ 7800 rpm and a good 305 520 hp.

DG testing his 1968 Tony Southgate designed USAC weapon, the Mk4 G-W V8 at Riverside, warm down lap without the goggles. Ho took 3 race wins and Bobby Unser 3 in a customer car including the Indy 500, Ford Indy DOHC V8 powered (AAR)

Eagle Mk4 Ford G-W front and rear- front and rear suspension utterly period typical- very successful Southgate design (AAR)

For the 1968 Can-Am AAR acquired a McLaren M6B and in a ‘lightness and dash policy’ took over 100 pounds out of the car by a cocktail of small-block 325 cid Ford G-W and the smaller, lighter Hewland DG300 gearbox. The track dimensions were narrower, the body lighter with a lower, longer nosepiece and suspension arms, exhaust system, gear linkage and bracketry were re-made out of titanium. The car was renamed McLeagle! It wasn’t enough of course, the Bruce and Denny M8A Chev 427 alloy blocked cars rolled over the top of the McLeagle, Lola T160, Ferrari 612P and all else in their path- Denny Can-Am champ that year.

In 1968 and 1969 the John Wyer entered, Gulf sponsored Ford GT40 chassis ‘1075’ won the Le Mans classic fitted with Gurney-Weslake Ford engines.

The honours were taken by Pedro Rodriguez and Lucien Bianchi in ’68 and Jacky Ickx and Jackie Oliver in ’69. In 1968/9 despite the Mk1 GT40 hardly being in the full flush of youth the gorgeous, somewhat heavy G-W engined machines won many endurance classics against more modern Porsche, Alfa Romeo, Matra and Ferrari’s (in 1969)- the 1968 Brands Hatch 6 Hour, Monza 1000 Km, Spa 1000 Km, Watkins Glen 6 Hour and 1969 Sebring 12 Hour and Spa 1000 Km.

In period the Le Mans winning engines gave circa 440 bhp @ 6800 rpm- that is 302 cid Ford V8, Gurney Weslake heads fed by four Weber 48IDA carbs.

Lucien Bianchi, Pedro and the boys after the ’68 Le Mans win- ‘1075’ one of the most famous of all Le Mans winners with two notches on its belt (unattributed)

John Wyer GT40 at the factory circa 1969. Note the Gurney Eagle’ rocker covers, FIA mandated luggage framework above the exhausts, engine and trasaxle radiar tors and Firestone tyres (unattributed)

In a busy 1968 for AAR, in a commercial approach to capitalise on the cylinder head designs Gurney started to make modified versions of the heads cast in LM8 aluminium by the Aeroplane and Motor Foundry in England for road cars.

The racers Hilborn fuel injection was replaced with a four-barrel carb. Anticipating a large order from Ford, the heads had detuned combustion chambers and were of a budget design. They could be machined with different sized ports and/or valve sizes to the specification of the full racing heads despite some of the internal passageways being of differing sizes to the race heads.

When no manufacturer (Ford or Lincoln/Mercury) chose to fit the heads Dan was left with an enormous stockpile of them. ‘It didn’t’ happen because no-one big enough got behind it. If someone like Henry (Ford II) would have said “Hey guys, why don’t you do this?”, that would have been all it would have taken’ offered Gurney. A trial assembly run was arranged by Gar Laux, head of Lincoln-Mercury but perhaps the idea fell foul of the ‘not invented here’ notion.

Many of the surplus heads were converted to as near as racing specifications as the Gurney factory could make them and were fitted to Indy cars. None of these heads were fitted ‘in period’ to GT40’s. All GT40 heads were made at the William Mills foundry and were a higher grade casting with the full race combustion chambers, porting and passageways. The Airplane and Motor cast heads were usually branded as Gurney Eagle although some will over time have been retro fitted with Gurney Weslake rocker covers.

This G-W Ford in Dan’s 1969 Eagle Mk7 ‘Santa Ana’ features Mk 4 heads with canted injectors. This close up shows the Hilborn slide injection, lots of ‘Aeroquip’ lines and AAR’s fine attention to engineering detail- checkout the fabrication of those extractors and rather critical throttle components (AAR)

 

Gurney, Eagle Mk4 Ford G-W 305 cid, Indy 1969 (D Friedman)

Into the 1969 Can-Am without the Ford factory support he hoped for Dan raced the same McLeagle with a very special, aluminium 344 cid small-block Ford G-W.

Some of the Can-Am rounds conflicted with his USAC commitments, back at AAR the team toiled with a three valve G-W variant to sit atop specially cast ally Ford blocks. After various development problems kept it off the tracks Dan bought a 7 litre Chev and popped in into the McLeagle, qualifying ninth at Michigan- but tasted a great Can-Am machine when he raced the spare McLaren M8B to third behind Bruce and Denny having started from the rear of the grid.

Pete Lyons wrote ‘…from the back…he passed twelve cars on the first lap…Each lap Dan passed fewer cars but he passed them relentlessly. He gave the impression of being careful, feeling out the car, not risking breaking it, yet the big orange gun shot his black helmet along like a cannonball. When he caught Brabham, he went by so fast the two could hardly exchange glances…’Jack knew exactly how Dan felt as Brabham tested the same car during qualifying- and did a time in a limited number of laps good enough for row two of the grid!

The dark side- 7 litre Chev engined McLaren/McLeagle M6B at Michigan in 1969 (unattributed)

In tragic circumstances, after Bruce’s death at Goodwood, Dan raced a works McLaren M8D Chev with great speed and success until sponsorship conflicts intervened and stopped his campaign short- a great pity as a Hulme/Gurney battle for the 1970 Can-Am title would have been a beauty. It was a fascinating season in the short history of the series inclusive of the Chaparral 2J Chev ‘Sucker’ machine, to have finally seen Dan in a car truly worthy of him would have been something, albeit not G-W Ford powered.

(AAR)

Into 1970 the AAR USAC machine, the ‘7000’ designed by Len Terry was both Offenhauser and Ford G-W powered- and achieved its final G-W stock-block win in Swede Savage’s hands at the season ending finale at Phoenix, the 1971 ‘7100’ was designed by Roman Slobodynski was built to suit the Drake Offy turbo-charged four cylinder engine only.

What a marvellous run the Gurney-Weslake small-block Ford V8’s had…

Swede Savage in the 1970 Indy 150 at the Indianapolis Raceway Park all crossed up in the Eagle 7000 G-W Ford, classified 8th in the race won by Al Unser, Colt Ford Indy V8 (A Upitis)

Etcetera…

AAR Santa Ana workshops circa 1968/9 with 3 litre GW V12 in the foreground and FA/F5000 monocoques behind (unattributed)

 

Dan with gun AAR engine man John Miller ‘Mandrake The Magician’ with G-W Hilborn injected V8 (AAR)

Bibliography…

‘Dan Gurney’s Eagle Racing Cars’ John Zimmerman, ‘Can-Am’ Pete Lyons, gurney-weslake.co.uk, phystutor.tripod.com

Credits…

The Enthusiast Network, Dave Friedman Collection, AAR Archive

Tailpiece: Dan aboard his second placegetting Eagle Mk4 Ford G-W, Indy 1968…

(D Friedman)

Finito…

Comments
  1. David Thompson says:

    These engines were reported as “Fords.” We did not know about them at the time. Thank you for the information.
    By the way, how did they change the spark plugs?

    • markbisset says:

      Yes David,
      Plug change on the engine stand easy- on the T70 in the paddock slightly more challenging!
      The Gurney Weslake heads were always well known in period but it probably wasn’t in Dan’s commercial interest given Ford’s support to overplay his hand. I hadn’t realised how close he came to Indy wins with the engines mind you- a bit of history I wasn’t aware of.
      Mark

  2. colin artus says:

    Ooops – had a better look at the pics and most, if not all, do seem to show a Hilborn setup. I’ve got a pic of the Gurney Lola from Bridgehampton in ’68 sporting the Lucas system.

    • markbisset says:

      Thanks Colin,
      Have fixed the Le Mans capacity, error on my part, the 302 V8 was fitted into Australian Falcons from the ’68 model year- no doubt it was available in the US before that.
      The choice of Hilborn injection is an interesting one given Dan’s familiarity with Lucas in Europe, not least in the G-W V12. It would be interesting to know why they went that way, I’ve not tripped over that point in my research.
      The Le Mans eligibility of the heads is interesting too- enough of them must have been built to have been homologated though. But not enough to have been eligible for Formula 5000- a great shame!
      Mark

  3. Brian Simpson says:

    Fabulous article Mark , a great era of Motor Sport .

    • markbisset says:

      Cheers Brian,
      It’s an era just before my personal involvement- and we all have our favourite period I guess, but 1950 to 1970 was very much ‘in the zone’ across the globe if sub-optimal from a driver survival perspective!
      Mark

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