Posts Tagged ‘BRM P75 engine’


Jim Clark takes a deep breath as he aims his big, heavy Lotus BRM around Oulton Park in 1966…

The Oulton Park Gold Cup was one of  numerous non-championship F1 races run in the mid-sixties.

Clark practised the car but discretion was the better part of valour, he raced his reliable, nimble Lotus 33 Climax in the race won by Jack Brabham’s BT19 Repco, the dominant car of 1966. The great Scot finished third in the 33, a car he took over from teammate Peter Arundell after the H16 engine in his Lotus blew up shortly after setting the third fastest time, a time equalled by Jackie Stewarts’ BRM ‘H16’.

The H16 engine famously had its only victory, in a Lotus 43 in Clark’s hands in the US Grand Prix several months later.


Brian Watson’s shot of the smoky H16 engine in Clarks’ Lotus 43 about to pop at Oulton Park!

The Lotus 43 was a much maligned car, the facts tend to suggest it wasn’t quite as bad as many would have us believe.

Clark raced one four times- in the 1966 Italian, US and Mexican GP’s and in the first of the 1967 Grands’ Prix, in South Africa. He scored one win at Watkins Glen, qualified on the front row three times, once on the second and was competitive in all four events. I’m not saying he wasn’t happy to race a nimble 33 at Monaco, rather than the 43, or that he was sorry to forsake the 43 for the 49 at Zandvoort however!

It’s also technically interesting in that the P75 BRM engine was used as a stressed member of the chassis in the same way the Ford Cosworth DFV in the  49 which followed was. Much is made of this aspect of the Ford DFV’s attachment medium to the car, but Vittorio Jano used the technique in his 1954 Lancia D50 GP car. It wasn’t the first time it was done whatever the Ford/Lotus PR machine of the time would have had us believe.

The BRM engine was attached to the rear bulkhead, as was the DFV to the 49. The suspension was mounted to the engine and gearbox as was the case with the 49.

Look at the 43 and 49 from the front and they are hard to pick. Conceptually they are similar in terms of chassis and suspension. Look aft of the rear bulkhead and the massive girth of the BRM engine is in marked contrast to the svelte Keith Duckworth designed, Ford Cosworth 3-litre DFV V8. Chapman famously concepted the engine he wanted, and the means by which it was to be attached to his chassis.

Jim Clark Lotus 43 BRM Italian GP 1966

The BRM P75 engine was a massive lump, essentially it was two of the P56 BRM 1.5-litre V8’s, but at 180 degrees, placed on top of each other.  Its designed weight of of 380lbs ballooned to 555lbs, the DFV weighed less than 400 pounds.

Road and Track magazine published the scrutineered weights of the cars at the 1966 Italian Grand Prix. The Twiggy-like Brabham BT19 weighed 1,219lb, a marked contrast to the Cooper Maserati at 1,353lb. The pork-chop BRM and Lotus 43 were 1,529lb and 1,540lb respectively.

Mind you, the Honda topped the scales at 1,635lb. Interestingly the Hondola (Lola designed chassis) which won at Monza in 1967 weighed 1,309lb, a loss of 150 pounds in twelve months, whereas the BRMs, without a visit to Jenny Craig had porked up to 1,570lb- the Lotus 49 weighed 1,200lb.

The DFV at that stage developed about 405bhp, whereas the BRM P75 H16 never developed its claimed 400bhp, and had a lot of weight to carry.

The Lotus 43 was far from the worst Lotus ever built. Many of its GP cars didn’t win a GP, for sure the BRM P75 H16 engine was never to have the reliability of the 49’s Ford Cosworth DFV – one wag described it as ‘the spacer between the rear bulkhead and the gearbox’, such was its dependable nature!

The 49 deserves its place in the pantheon of Great Grand Prix cars but the 43 is conceptually closer to the 49 than Chapman- and Ford wanted to admit at the time.

Jim Clark Lotus 43 BRM US GP 1966

Clark launches his Lotus 43 off the line at the start of the 1966 US GP. He is using the BRM teams spare ‘H16’ engine, his own failed at the end of practice having just qualified behind Brabhams BT19 on pole. Clark, against the odds won. That’s Surtees Cooper T81 Maserati behind and the nose of Bandini’s Ferrari (unattributed)

Jim Clark Lotus 43 BRM Monza 1966

Clark looks happy enough as he mounts his Lotus, Monza 1966. It looks like Brabham’s BT19 Repco being pushed alongside – bulk obvious, weight of engine and gearbox 675 lbs! (unattributed)

Lotus 43 BRM drawings


Jim Clark Lotus 49 Ford Dutch GP 1967


Front shot of the Lotus 49 Ford at Zandvoort 1967, Clark up.

He won on debut after Hill’s car retired whilst in the lead – not so different from the 43 at the front at least!

Lotus 49 Ford rear, Clark Dutch GP 1967


The delicate rear end of Jim Clarks’ Lotus 49 Ford on its debut at the Dutch Grand Prix in 1967. In marked contrast to the big, butch BRM ‘H16’!

ZF five-speed gearbox, suspension and chassis design oh, so similar to the Lotus 43, as was attachment of engine to chassis and its use as a stress bearing member

BRM H16 engine article

Photo Credits…

The Nostalgia Forum, Brian Watson