Posts Tagged ‘Brabham BT20 Repco’

(R Wolfe)

Bugger!

Led Zeppelin first recorded ‘Communication Breakdown’ in 1969, although it was part of their live set from 1968. My whacko brain thought of that song and riff upon seeing this bit of ye olde school communication…

It would have been perfect if the song originated from 1967 given the date of the Brabham Racing Organisation team-leader’s (thaddl be Brabham JA) letter to the General Manager of Repco Brabham Engines Pty Ltd, Frank Hallam Esq is, according to Rodway Wolfe’s handwritten scrawl, 24 May 1967.

These days we have that internet thingy which makes our lives so instant in terms of communication, back then it was ‘snail mail’ or Telex machine if you were from the big end of town. I guess airmail from Surrey, UK to Maidstone, Victoria, Australia was three days or thereabouts? And the same in return with a neato ‘Par Avion’ sticker and a more expensive stamp affixed.

Jack’s note was sent between the Monaco and Dutch GP’s.

BRO had shown plenty of pace early in the season with Brabham and Hulme on pole and with fastest lap respectively at Kyalami albeit Pedro Rodriguez took the South African GP win in his Cooper T81 Maserati.

Jack flicking BT19 around with the abandon so characteristic during 1966-7. RBE740 powered, here ahead of Jim Clark’s Lotus 33 Climax FWMV 2 litre DNF, with Jack’s motor about to go kaboomba (unattributed)

At the following championship round- Monaco, Jack was on pole deploying the new RBE740 Series V8’s power and big, beefy mid-range punch for the first time in a championship round. But an unhappy early ending to the weekend was the Aussie’s new moteur breaking a rod on the first lap of the race. Denny won his first GP in a 620 engined BT20, so it was far from all bad from the team’s perspective- the race tragic for the sad demise of Lorenzo Bandini after a fiery crash aboard his Ferrari 312.

Merde! or Australian vernacular to that general effect- Brabham checks the hole in his nice new 700 Series Repco block, carved up somewhat from an errant conrod- Monaco 1967

But all the same their would have been a bit of consternation in the camp at the time, no doubt a phone call to Hallam was made about the buggered rod, or maybe Frank read about it in the late edition of Monday’s Melbourne daily ‘The Sun’?

The Lotus 49 Ford Cosworth DFV changed the GP world when it appeared in the hands of Clark J and Hill G at Zandvoort on June 4- the need to lift was clear!

So, lets address Jack’s requests.

Sorry about that sketch of Brabham’s requested 700 Series block modifications! Sadly we don’t have it- which is a bumma.

The modified Daimler rods and caps are RB620 bits, not 740- so Jack is after some bibs and bobs to keep alive some of the RB620’s by then in circulation in Europe. Not to forget Denny was still using RB620’s until he got a 740 for Spa in mid-June. The ‘620 Series’ Repco was the first of the Repco Brabham Engines series of race V8’s and was based on the standard Oldsmobile F85 block- ‘600 Series’ block and ’20 Series’ cross-flow heads in Repco nomenclature. The ‘740 Series’ was the new for 1967 motor- ‘700 Series’ bespoke Repco designed block and ’40 Series’ exhaust within the Vee heads.

The water rail changes appear routine race experience evolution, in fact whilst the whole letter is dealing with normal stuff its still interesting, if you know what i mean? And the engine fitters will have been given the bief to watch the chain tensioner fit.

Jack’s checklist of engine parts is interesting.

I thought all of the RBE engine rebuilds happened at Maidstone but clearly that is not the case, some engine work was being done in The Land of The Pom. Interested to hear from you RBE lads on this point.

Brabham and Hallam at Sandown with their newborn, January 1966 (R Wolfe)

The photograph above is of the two participants in the above correspondence at Sandown Park, Melbourne during the 1966 Tasman round. It is a ‘pose for the press’ shot given the race debut of the Repco V8 in the companies home town.

It was the second race for the RBE620 Series V8- the first was a 3 litre unit used by Jack during the non-championship South African GP weekend on 1 January, DNF with a fuel injection pump problem.

The engine above is a 2.5 litre jobbie- easily picked by its long Lucas injection trumpets, this time an oil pump broke- the chassis is the one and only BT19 which carried Jack to the 1966 title, and as can be seen in the Monaco photographs, well into 1967. The RBE620 became a paragon of reliability after some initial traumas were rectified…

The RBE 620 Series engine story is here;

https://primotipo.com/2014/08/07/rb620-v8-building-the-1966-world-championship-winning-engine-rodways-repco-recollections-episode-2/

The RBE 740 Series engine story is here;

https://primotipo.com/2016/08/05/rb740-repcos-1967-f1-championship-winning-v8/

Tailpiece: Denny en-route to Monaco victory aboard an RBE620 powered Brabham BT20, Jo Siffert’s Rob Walker Cooper T81 Maserati behind DNF…

Credits…

Rodway Wolfe Collection, Getty Images, Bernard Cahier

Finito…

(Ron Laymon)

Denny Hulme caresses his Repco Brabham ‘RB740’ V8 in the Mosport pits during the Canadian GP weekend, August 1967…

As well he should too, it was this engine which powered his Brabham BT24 to victory in that years drivers championship. Mind, you that statement is not entirely correct as Denny used the ’66 engine, ‘RB620’ early in the season as Jack raced the 740, that engine was only used by the Kiwi after Jack deemed it available and raceworthy to him.

In the meantime Denny scored 4th in South Africa and won at Monaco using RB620 V8’s- those results won Denny the title really, Jack was 6th and failed to finish in the same two races. Denny’s 51 points took the title from Jack’s 46 points and Jim Clark with 41.

Clark from Hill during the 1967 British Grand Prix at Silverstone, Lotus 49 one-two for a while at least, GH retired with engine failure on lap 64 to end a dismal weekend, he crashed after suspension failure on Saturday. Clark won from Hulme’s BT24 and Chris Amon’s Ferrari 312 (Sutton)

Clark’s 4 wins shaded Jack and Denny with two apiece in the epochal Lotus 49 Ford Cosworth. Any design which is competitive over four seasons, inclusive of drivers and manufacturers title wins (Hill in 1968 and Rindt in 1970) is ‘up there’ in the pantheon of great GP cars. The 49’s first win was Clark’s victory at Zandvoort in ’67 upon the cars debut, its last the result of Jochen Rindt’s stunning tiger drive at Monaco in 1970- at his friend Jack Brabham’s expense, the great Aussie pressured into a famous last lap error by the storming Austrian.

Without doubt the Lotus 49 was the car of 1967, its always said it would have won the title with more reliability that it did not have as a brand new car.

But that simple analysis fails to give credit to the Aussies.

The Brabham BT24 was a ‘brand-spankers’ design as well. Tauranac says that it was only his second ‘clean sheet’ GP design, his first was the BT3 Climax which raced from mid-1962. The GeePee Brabhams which followed were evolutions of that design.

Love these close-up shots. Its Denny’s BT24 and RB740 engine the cam cover of which has been removed to give us a better look. The cars spaceframe chassis is clear- small car for the era. Based on Tauranac’s BT23 F2 design the engine was tightly proportioned and economical of fuel so the package around could also be tight. From the bottom you can see the distinctive ribs of the 700 block below the top suspension radius rod. To its right is an ally tank held in place by a rubber bungy cord, a fuel collector which picks up from the two, one each side, fuel tanks. SOHC, 2 valve V8, circa 330 bhp in period. Cams chain driven. Note the rail carrying coolant behind and above the camshaft. Fuel injection is the ubiquitous, excellent Lucas product, to the left is the top of the Bosch twin-point distributor. In the centre of the Vee is a hornets nest of carefully fabricated exhausts- wonderful examples of tube bending art. Ferrari fitted 12 within the Vee of its engine in a trend common at the time. The idea was to get the pipes outta the breeze and away from suspension members. What a wonderful bit of kit it is (Laymon)

The ‘RB740’ SOHC, 2 valve, ‘between the Vee’ exhaust engine was also a new design. Both the Repco designed, Commonwealth Aircraft Corporation cast ‘700 Series’ block and the ’40 Series’ heads (the heads were cast by Kevin Drage at Clisby Industries in Adelaide) were new. They were completely different to RB620, albeit the 700 block could and was bolted to 20 Series heads and ancillaries when 620’s were rebuilt and its modified Oldsmobile F85 block cast aside as no longer fit for purpose.

Jack and Repco ‘blooded’ or tested the head design in the early 1967 Tasman races but the block was not ready then- the 2.5 litre 1967 Tasman engines were ‘640 Series’, a combination of the ’67 heads and the 1966 modified by Repco, Olds F85 blocks. The first 700 blocks were used in F1, not the Tasman Series. In fact the early ’67 F1 engines used by Jack were 640’s as well. Denny used 620’s early on in ’67, as mentioned above just to add to the confusion!

My point is that the all new Brabham BT24 Repco won 4 races and took the ’67 drivers and manufacturers titles beating the all new Lotus 49 Ford which also won 4 GP’s- Graham Hill was winless in the other 49 that year. (I’ve ignored the 49’s guest drivers in this analysis)

BT24 sans Hewland DG300 during the German GP weekend. Elegant simplicity of the design laid bare. Spaceframe chassis, rear suspension comprising single top link, inverted lower wishbone, coil spring/damper, twin radius rods and an adjustable roll bar. Eagle eyed Aussies may note the ‘Lukey Muffler’ tipped exhausts (unattributed)

It could also be said that the 49 chassis design was not really all new- the 1966 Lotus 43 is identical in layout inclusive of suspension and using the BRM H16 engine as a stressed member, as the Ford DFV was.

So whaddam I saying?

That the spaceframe Brabham BT24 Repco combination was ‘newer’ than the monocoque Lotus 49 Ford which was really the 43 chassis design, suitably lightened and modified to carry the DFV, a much lighter and fuel efficient moteur than the sensational but corpulent, complex BRM engine. Let the correspondence begin! Here is a link to my Lotus 43 BRM article, form a view yourselves.

https://primotipo.com/2015/02/17/jim-clark-taking-a-deep-breath-lotus-43-brm/

Tell me in a conceptual sense how the 49 chassis and suspension differs from the 43? There was plenty of Ford funded PR hoopla around the Lotus 49, we have all seen the footage. It was hardly going to be the case that Chapman said of the Lotus 49 chassis ‘we needed a known platform to bolt the new engine to, so we used the BRM engined 43 chassis design with minor mods to suit the much lighter, smaller DFV’. Much better to tout the whole lot as ‘all new’- no drama in that, its all fair in a corporate bullshit sense, its just not quite true and largely a myth perpetuated by many over time. Time after time!

Lotus were not the first to use the engine as a stressed part of the car either, although that is widely attributed to Chapman. Jano did it with the D50 Lancia, Ferrari with the 1512 and BRM the P83 H16.

In any event, lets give the Brabham BT24 Repco ‘740’ V8 the respect it deserves but seldom gets.

Clark in the Mosport paddock 1967, his eyes well focused on the fashionably attired young Canadian missy, despite having just bagged pole. Lotus 49 Ford (unattributed)

Canadian GP Mosport- 27 August 1967…

This first Canadian F1 GP was in many ways an exemplar of the words above. Clark and Hill qualified 1-2 with Denny sharing the front row on Q3.

Clark led from the start to be passed by Hulme, Denny’s flat, fat Repco torque curve was more suited to the slippery wet conditions than the DFV which was notoriously abrupt in its power delivery early in its development. Bruce McLaren’s BRM V12 engined M5A was up to 3rd at one point. As the track dried Clark worked his way into the lead- which he kept after rain started again until lap 68 when the engine cut out. Jack won from Denny with Hill in the other 49 4th and Canadian driver Eppie Wietzes a DNF during a Lotus 49 guest drive with the same ignition dramas as Clark.

Maybe the truth is that the difference between the Lotus 49 and Brabham BT24 in 1967 was that Clark sat aboard a Lotus not a Brabham? For sure Jimmy would have been lightning fast in the light, chuckable BT24. Faster than Jack and Denny for sure.

Graham Hill quizzing Jack about the pace of his BT20 ‘640’ at the Silverstone BRDC International trophy in April 1967, Mike Parkes Ferrari 312 took the win from Jack. Red car is Bruce McLaren’s McLaren M4B BRM (Schlegelmilch)

A further point is around car preparation. The 1962/68 World Champion, Hill G, still at the peak of his powers was effectively neutered from the time the 49 appeared by the unreliability of the chassis he drove- of his 9 Lotus 49 starts he retired 7 times. Three of those were engine failures, the others due to driveshaft, suspension, gearbox and clutch problems. Clark retired 3 times in the same 9 races with ignition, suspension and ZF tranny dramas.

Brabham Racing Organisation prepared beautifully consistent cars in 1967 powered by very reliable Repco engines. Factory Brabhams took the championship F1 startline 22 times in 1967 for 4 DNF’s, all due to 740 Series engine failures- Jack’s broken rod at Monaco, both drivers at Spa and Denny’s overheating at Monza.

Clark was far and away the quicker of the two Lotus men- Jim started from pole in 6 of those 9 races, Hill from pole in 3 of them. As I have said before ‘if yer aunty had balls she’d be yer uncle’- but IF Hill had won a race or two that Clark did not, the manufacturers title would have been Lotuses not Brabhams. Because the lads from Hethel did not prepare two equally reliable cars the title was Brabham’s not Lotus’, surely a fair outcome?!

Denny Hulme in his ‘brand spankers’ Brabham BT24 Repco ahead of Chris Amon’s Ferrari 312 during the 1967 French Grand Prix, Bugatti Circuit, Le Mans. Jack won from Denny, Chris retired on lap 47 with a throttle linkage problem. The Ferrari 312 was a big car, the sheer ‘economy’ of the little, light, BT23 F2 derived BT24 shown to good effect in this shot. Note the air-scoop used to cool the fuel metering unit in the Tasman and some of the ‘hot’ races in the GP season (unattributed)

Denny’s 1967…

Didn’t he have a ripper season! In addition to the F1 drivers title he could easily have won the Can Am Series in Bruce McLarens M6A Chev, the first of the wonderful ‘papaya’ cars too. He went back to Mosport a month after the Canadian GP and won the Can Am race in addition to wins at Road America and Bridgehampton. Bruce just won the title with a smidge more reliability than his Kiwi buddy, 30 points to 27.

Denny didn’t have great reliability in the Tasman Series at 1967’s outset but then again the Brabham main game was engine development in advance of the GP season’s commencement. The cars were match fit for the World Championship partially due to development work done in Australasia by Jack, Denny and Repco in January and February whilst Tauranac beavered away on his new BT24 chassis design back in the UK- which is about where we came in!

Michael Gasking in grey coat and Roy Billington in shirtsleeves fitting a 2.5 litre RB640 V8 at Repco Maidstone during the 1967 Tasman. Cars raced in the ’67 Tasman were BT22 ‘F1-1-64’ for Denny and BT23A ‘1’ for Jack. The latter car is very much the F1 ‘BT24 prototype’ being a modified F2 BT23 frame to which the RB640 engine was adapted. Not sure which car is being fettled in this photo. It looks as tho they are about to fire her up- you can just see the end of a white ‘Varley’ battery by Roy’s foot and a red slave battery alongside. The motors Bosch distributor cap is missing but not a big deal to fit. The sound of those engines is oh-so-sweet! Not sure who the other two dudes in shot are, intrigued to know (Gasking)

Who Says Ron Tauranac designed the Brabham BT24?…

The BRO lads based themselves at Repco’s Maidstone headquarters in Melbourne’s western suburbs during the Tasman Series to fit engines before the Kiwi rounds and before/between the Sandown and Longford rounds in Melbourne and Tasmania each year. These two events were traditionally the season enders.

During these trips Jack, Denny, Roy Billington and others out from the UK operated from Maidstone both preparing the cars and spending time with the guys who built their engines. The Repco fellas all have incredibly strong, happy memories of these times.

The sketch below was made by Jack and Denny in the Maidstone lunch-room during a break in the days proceedings on the ‘1967 tour’.

Michael Gasking recalls that in between tea and bikkies the ‘guys were explaining to us what the ’67 F1 car would look like and its key dimensions’- so there you have it, Jack and Denny’s conceptual thoughts on the ’67 F1 car! The funny thing is, at that time, early March 1967 Ron Tauranac may not have been too far advanced with the ’67 chassis, the first didn’t appear until Jack raced BT24/1 at Spa on 18 June.

In the interim Ron was busy at Motor Racing Developments pushing F2 Brabham BT23’s out the door- far more profitable work than knocking together a few F1 cars for Brabham racing Organisation!

In any event, what a wonderful historical document! JB’s rendering of the RB740 engine is sub-optimal mind you, but its clear the guys have taken the time to carefully draw the car in pencil, and then add the dimensions in ink, or ‘biro’ I should say!

(Gasking)

Its hard to compare all of the BT24’s publicly reported dimensions with Jack’s sketches level of detail but the total height of the car at 34 inches tallies, whereas Ron’s final wheelbase was 94 inches rather than Jack’s 91.5 inches.

Re-engineering Jacks total width from tyre to tyre outside extremities at the rear of 69 inches- to a rear track dimension, using his 12 inch wide tyres, gives a rear track calculation of 57 inches for Jack whereas Ron’s was 55 inches.

The little air-ducts either side of the nose and in front of the driver didn’t make it, the steering wheel diameter agrees at 13 inches mind you these were trending down to what became the 10 inch norm. The outboard suspension layout all around is spot on of course, as is the use of a V8 engine…

At the end of the lunch, Michael scooped up the drawing which is now, 50 years later shared with us, many thanks Michael! Wonderful this internet thingy, isn’t it?

(Max Millar)

Related Articles…

On the Repco RB740 engine

https://primotipo.com/2016/08/05/rb740-repcos-1967-f1-championship-winning-v8/

The 1967 Repco Brabham season

https://primotipo.com/2015/09/03/life-magazine-the-big-wheels-of-car-racing-brabham-and-hulme-30-october-1967/

Hulmes 1967

https://primotipo.com/2014/11/24/1967-hulme-stewart-and-clark-levin-new-zealand-tasman-and-beyond/

Tailpiece: 1967 wasn’t all plain sailing, Brabham, Monaco…

(Getty)

Jack looking intently at the sight of his RB740’s Laystall, steel crankshaft. He can see it thru the side of the engines block, an errant connecting rod has punched a hole in its aluminium casing! Dennis Jenkinson’s MotorSport Monaco ’67 race report records that JB started the weekend with an RB640 engine fitted, and popped a new 740 in- which had circa 20bhp more, which he ran-in on Saturday and then qualified with, on pole.

Bandini got the jump at the start with the rod failing on the journey to Mirabeau, whereupon Jack spun on his own oil, travelling backwards all the way to the Station Hairpin, in the middle of the jostling pack. But the robust engine continued to run on 7 cylinders for the journey back to the pits, where this photo was taken, the great Aussie inadvertently trailing oil all the way around the course, the lubricant having an easy path out of the moteur via a not insignificant hole!

The rod problem was quickly fixed by Repco who fitted Carrillo’s- drama solved. The chassis is BT19, Jack’s ’66 Championship winning frame. Brabham first raced a BT24 at Spa on 18 June, Denny did not get his until Le Mans on 2 July. So you might accurately say the ’67 drivers and manufacturers titles were won with a mix of 1966 and 1967 chassis’ and engines!

Bibliography…

 ‘Brabham, Ralt, Honda: The Ron Tauranac Story’ Mike Lawrence, GP Encyclopaedia, Michael Gasking, ‘History of The GP Car’ Doug Nye, Garry Simkin

Photo Credits…

 Ron Laymon, Michael Gasking Collection, Sutton, Getty Images, Max Millar

Postscript: Jochen Rindt driving the ring off the BT24 at Kyalami, South Africa on 1 January 1968- he was third behind a Clark, Hill Lotus 49 1-2. Clark’s last F1 win sadly…

 

 

 

 

image

(Schlegelmilch)

Silvio Moser’s Brabham BT24 Ford racing with Lancia D50 style pannier tanks during the 1969 Monaco Grand Prix…

He retired from the race won by Graham Hill’s Lotus 49B. Moser is one of those privateers who so enriched GeePee racing in the days when such things were allowed, encouraged even.

Silvio was keen on Brabhams, he raced an ex-works BT20, Denny’s chassis ‘F1-2-6’ in 1968 before buying the car above, BT24/3 after Piers Courage raced it in the 1969 Tasman Series.

bt 20

Silvio is his Charles Vogele Racing Team Brabham BT20/2 Repco. DNF, Daily Mail Race of Champions meeting, Brands Hatch, 17 March 1968. Bruce McLaren won in his M7A Ford (Ed Lacey)

It was the last of the BT24’s built, Jochen Rindt raced the 1967 championship winning design during early season ’68 Grands Prix whilst Jack tried to coax some reliability from the quad cam, 32 valve, powerful but problemmatic ‘860 Series’ Repco V8 engined BT26.

brab rindt

Jochen Rindt’s Brabham BT24/3 Repco, his ’67 spec ‘740 Series’ Repco SOHC V8 powered car beside Jack’s new BT26 powered by the ‘860 Series’ DOHC, 32 valve V8, DNF for both, Monaco 1968. Hill won in a Lotus 49 B Ford (Schlegelmilch)

Dan Gurney also had a steer, the lanky Californian crammed himself into the car at Zandvoort (below) then Kurt Ahrens raced it to 12th in the German GP, the cars only GP finish in 1968.

brab dan

Kurt Ahrens (below)  in BT24/3 during the awfully wet German GP at the Niuburgring, Jackie Stewart triumphed in his Matra MS10 Ford aided by some trick Dunlop wets. Kurt was on Goodyears, finishing 12th in a one off drive on home turf. The cars spec was ever evolving, check out the wing package, the same as that used on the factory 1968 BT26’s, Nurburgring was the only race of the year in which both Jack and Jochen finished a race in the fast but unreliable BT26. Kurt’s cars wing has ‘Fosters Flop’, it’s in full droop mode, the simple support bracket having come adrift on the bumpy Eifel Mountains course.

image

(Unattributed)

Frank Williams then bought the car and converted it to Tasman spec by fitting a Ford Cosworth DFW V8, the 2.5 litre variant of the famous DFV. Piers did well in it in the Antipodes, his best result 1st at the Teretonga International on 25 January 1969. Here (below) he is behind Jochen Rindt’s Lotus 49 DFW and the Ferrari 246 T twins of Chris Amon and Derek Bell, the ‘flash’ grandstands nicely juxtaposed against  the cars. Might be on the warm up lap as Jochen’s driveshaft failed on the line, the cars are in grid order.

puk 1

(Ian Peak)

And below Bell’s Ferrari 246T from Hill’s Lotus 49B and Courage’s BT24/3. Courage won from Hill and Amon. Variety of approaches to wings interesting, checkout that crowd and the el-casual vantage points.

puk 2

(Ian Peak)

Courage had a sensational season driving another ex-works Brabham, a BT26 adapted to accept a DFV, he established himself as an F1 front runner in 1969, 2nd at Watkins Glen to Jochen Rindt the seasons highlight.

Frank Williams popped the BT24 into Autosport after the Tasman to sell it, Silvio the eager purchaser. All the hard work had been done, he bought a DFV and slotted it into the spaceframe whence the DFW had been. He needed more tankage though, Tasman races were 100 miles, GP’s 200 miles, hence the pannier tanks, ok for 1969 but no-go in 1970 when ‘bag tank’ rules came into being.

BT24/3 still exists in Switzerland, there is also a replica tagged 24/3.

dutch

Silvio’s Brabham BT24 DNF engine, about to be swallowed by Amon’s Ferrari 312 3rd, Hulmes McLaren M7A Ford 4th and Brabham’sBrabham BT26 Ford 6th, Zandvoort, Dutch GP June 1969 (unattributed)

Credits…

Rainer Schlegelmilch, Ed Lacey/Popperfoto, Ian Peak Collection/The Roaring Season

oldracingcars.com

Tailpiece: Silvio Moser on his way to a great 6th place in his Brabham BT24/3 Ford at Watkins Glen during the 1969 USGP, he is being passed by Jacky Ickx’ latest, works Brabham BT 26 Ford DNF. Rindt won in a Lotus 49B Ford…

ickx

(unattributed)