Remembering F1’s wild V10 era

| 28 Jun 2023
Classic & Sports Car – Remembering F1’s wild V10 era

Formula One’s banning from 1989 of forced induction in favour of 3.5-litre naturally aspirated engines was expected to reignite the V8 versus V12 (up to 180º) firefight that had raged long before – and for some time after – the turbos whistled in at the end of the 1970s.

Honda and Renault, however, chose the relatively unexplored V10 route, seeking a better compromise between fuel economy and revs, punch and packaging.

They would sweep the board in qualifying – it helped that Ayrton Senna was on board – and win 12 of that season’s 16 Grands Prix.

Others followed: prescient independents Ilmor and John Judd’s Engineering Developments were picked up by Mercedes-Benz and Yamaha; Peugeot joined in 1994, having twice won at Le Mans using a V10.

The trickle became a flood.

Classic & Sports Car – Remembering F1’s wild V10 era

Ayrton Senna wins the 1989 San Marino Grand Prix ahead of teammate Alain Prost, securing the first victory of the V10 era © Getty Images

Though Honda, after 1992 and two seasons with a V12, and Renault (1997) departed the scene – but kept their hands in via offshoots Mugen and Mecachrome – the 1998 F1 grid was chocka with V10 blocks, and the fact was made regulatory from 2000.

BMW, in 2001, and Toyota, in 2002, having planned a V12, then mixed in.

Ford and Ferrari had stuck to their V8s and V12s – nomenclatures and noises that had forged their brands – until after the post-Ayrton Senna 3-litre reset of 1995.

The Blue Oval (via Cosworth) had scored eight wins to Renault’s seven in the previous season – it helped that Michael Schumacher was on board – while the reds of Maranello had started this new atmo era strongly, but faded swiftly and horribly: Jean Alesi’s fortuitous, emotional and only Grand Prix victory – Canada, in 1995 – was the last for a V12 Ferrari.

Heart could no longer rule head: new recruit Michael Schumacher would never race a V12 – and 65 of his 72 wins for the Scuderia were with a V10 at his shoulder.

The configuration had occasionally been used by diesels (some of them two-strokes) in locos, trucks and tanks since the 1930s.

In sporting terms, however, it had gone no further than a 1.5-litre drawn by Dr Ferdinand Porsche just before the outbreak of WW2, plus a few impressively noisy demo laps of Monza by a 3.5-litre Alfa Romeo ‘silhouette’ built for a ‘European NASCAR’ that never happened.

Yet Honda did not hesitate.

Talk of its having tested V8s and V12s prior to 1989 was just that.

“We went straight to V10,” says project leader Osamu Goto, who had overseen the company’s turbocharged supremacy with Williams and then McLaren.

“The V10 came about from conversations with Gérard Ducarouge [technical director of Camel Team Lotus Honda], his thoughts about the best engine concept for the new regulations.

“How best to package car and engine: total chassis stiffness, aerodynamics and agility.

“Before turbos, teams had mainly been private, without the resources of a major manufacturer, so they used a well-developed V8 by Cosworth.

“They were used to it. But we had more freedoms.

“At the first V10 test at Silverstone, Ayrton was unhappy: ‘Acceleration too sharp! Deceleration too sharp!’ The difference in engine braking compared with a 1.5-litre turbo was huge: the car pitched in corners, balance changed and the driver was uncomfortable.

“We tried to make the delivery more progressive.”

Classic & Sports Car – Remembering F1’s wild V10 era

Honda technical director and V10 supremo Osamu Goto at Jerez in 1990 for pre-season testing © Getty Images

“[Switching to] V12 was not just a technical decision,” Osamu continues. “Honda as an engine supplier historically is looking for the highest performance.

“We had decided on V10 for integration, and it was a success. So why not finally do a V12? More power. More revs. Sound is important because F1 is a show.

“It was successful, too [an unconvinced Senna won the 1991 title], but I think V10 was better for those regulations.”

The package of the Renault V10 in a bells-and-whistles Williams designed by Patrick Head and Adrian Newey was a match by mid-1991, and dominated in 1992.

Denied induced volumetric boosts, and with calorific value now regulated (teams were given six days’ notice in mid-1992 to use commercially available fuel), engine revs became the battleground.

Renault’s Jean-Pierre Boudy’s ‘Distribution Pneumatique’ redrew the redline in 1986 by replacing metal valve springs with valve closure by compressed-gas-controlled pistons, creating mass-less ‘springs’ without destructive high-rev resonances.

Now the bottom end set the limit, with secondary torsional crank vibrations at around 19,000rpm as ‘air valves’ became the norm (despite patents), bores swelled to almost 100mm and strokes ducked below 40mm.

Such radical ratios and rotations, however, have spiralling costs: as an engine denied time to breathe gasps for fuel and air, so frictional losses and inertia loads increase, some proportionally to the square of engine speed.

Compression beyond 13:1 becomes pretty problematic, too, as combustion chambers become increasingly disc-like.

And thus brake mean effective pressure takes a hit – to less than that of a V8 Ford-Cosworth DFV of 1967, albeit at double the revs.

If you wanted to be competitive, these unavoidables had to be compensated for. Some torque was salvaged by variable-geometry inlet trumpets: tall at low engine speeds and short at high revs.

Later iterations were infinitely variable thanks to concentric telescopic tubes extending or collapsing within each other, so more trombone than trumpet.

The main coping strategy, however, was mechanical efficiency: more accurate design and manufacture of improved materials; the minimising of reciprocating masses and reduction of their motion’s amplitudes; and the overcoming of frictions and pumping losses.

The brain and computing, manufacturing and purchasing powers of automotive and petro-chemical giants more invested in F1 than ever before went into overdrive.

Wall thicknesses were shaved to 2mm by better casting technology. Porting had more accurate finishing thanks to computer-numerical-controlled machining.

Classic & Sports Car – Remembering F1’s wild V10 era

The 3.5-litre V10 of the 1989 McLaren-Honda MP4/5 lurks in the pit garage at Hockenheim © Getty Images

Siamesed cylinder bores had super-thin dry liners. Crankshafts and valve stems were made more slender.

Pistons had peek-a-boo skirts and, until the prohibition from 2004 of pre-race engine swaps, no oil rings during qualifying.

Gear trains dispensed with reduction gears. Finger followers rather than bucket tappets were used to reduce weight and increase lift.

Crankshaft counterweights were bolted directly rather than press-fitted for smaller big-ends. Crankcases were divided into five sealed chambers to reduce windage losses.

Smaller amounts of lower-viscosity oils were used thanks to 3D visualisations and simulations of circulation. There was less coolant, pressurised to operate at 130ºC to enable smaller radiators.

Surface coatings and treatments such as diamond-like carbon handled higher specific pressures while reducing contact and sliding losses.

And every part had to be tuned to a resonating frequency outside the engine’s normal operating range, lest the whole shake itself apart.

All of which was offset against the FIA’s drive for improved safety – in simplistic terms by (hopefully) increasing lap times – while reducing costs.

Honda had in 1989 supplied McLaren with up to eight engines at a GP: three per car, in tailored specs – practice, qualifying, race – plus spares.

By 2004 a single engine had to suffice for an entire meeting on pain of a 10-place grid penalty. That requirement doubled in 2005. No wonder car-builders pounced on materials of greater potential.

At least six times stiffer than steel, a third of aluminium’s weight and boasting five times the heat-absorption of copper, beryllium – alloyed to aluminium to improve ductility – had been used initially in brake calipers. By 1998 Mercedes was using it in pistons and cylinder liners.

Piston speeds and accelerations shot up despite shortening strokes, and designer Mario Illien was able to use a longer stroke, promoting torque without compromising peak-rev performance.

Ferrari’s successful push to have it banned from 2001 was ostensibly for safety reasons – beryllium is a Group 1 carcinogen alongside asbestos and plutonium (and alcoholic beverages) – but likely was rooted in competitive shortfall and technical envy.

Even so, engines weighing less than 90kg (dry) were by 2005 reliably producing more than 900bhp.

Using the same fundamental architecture as the Cosworth DFV – oversquare cylinder dimensions, pent-roof combustion chambers with single central spark plugs and four-valve cylinder heads with twin overhead cams per bank – as well as fundamentally the same materials, they made designer Keith Duckworth’s 168kg, 408bhp masterwork look like a boat anchor and sound like a lawnmower.

Classic & Sports Car – Remembering F1’s wild V10 era

Jarno Trulli’s Toyota erupts in the pits at the Circuit de Catalunya during the 2005 Spanish Grand Prix © Getty Images

A V10 – odd-cylindered blocks combining for an even-numbered whole – is unbalanced by an end-to-end rocking couple.

Despite opting for the even firing intervals of banks set at 72º and sharing common crankpins, Honda’s 1989 first-generation attempt achieved 680bhp at 13,000rpm without air-valves, using a counter-rotating balance shaft to reduce vibration. But it was a heavy solution.

Ferrari’s V12 was lighter, while others preferred to live with (or work around) any roughness. Renault’s V10 remained a 67º unit until the end of 1996.

“It had a very high frequency that vibrated your back in a strange way, which made you cough until you got used to it,” says Damon Hill.

The 1996 World Champion had competitive experience of four makes of F1 V10: Judd, with Brabham during its dog days; its Yamaha cousin, with which he came within half a lap of winning the 1997 Hungarian GP in his Arrows; and, with Jordan at Spa the following year, he took the second of Mugen Honda’s eventual four wins.

He is best remembered, of course, for 21 victories in Williams-Renaults from 1993-’96.

“There are V10s and then there are V10s,” he continues. “Renault was fantastic at coming up with small increments the whole time: another 50rpm, another 10-15 horsepower.

“But it’s all very well having a lot of horsepower; what you need when you come on the power, usually at the low end of the rev range, is to be able to pick up the throttle and balance the car.”

“I spoke about it to the engineers at Viry-Châtillon: ‘I need it like an electric motor. As close as you can get to that,’” he remembers.

“It wasn’t like a two-stroke, nor was it a dragster with massive low-down torque, but it was well distributed across the range. It was very nice to drive.

“When I first ran it – in a FW13B, the ‘Thierry Boutsen car’ [of 1990] – it had a two-stage rev-counter that read to about 6000rpm, then went around again.

“I was told, ‘Don’t go over 9000!’ By the time I got back to the pits the car was on fire because I’d gone so slowly.

“Nobody had told me about the rev-counter. Revs were key and Renault was able to up them pretty rapidly. The rate of development was very aggressive when I started.”

“It’s a special noise – distinctive, evocative – and the buzz has never left me. I have footage on my phone of my old FW18 [of 1996] being fired up. I should make it my ringtone.”

Classic & Sports Car – Remembering F1’s wild V10 era

Heat of the moment: the 2005 Grand Prix of Turkey at Istanbul, and the final season of V10-powered F1 racing © Getty Images

“The presumption was that the Renault was the best back then,” Damon recalls. “But that Ford [V8 of 1994] was surprisingly good, although probably not as powerful.

“It used a manual gearbox and Michael did some strange downshifting: he kept his foot slightly open rather than blip it.

“I think he was blowing the diffuser, blasting it with exhaust gas. We couldn’t do that because we had a semi-auto.”

Ah, but was Hill cheesed off when his rival’s Benetton received Renault power for 1995? “Not half!” he replies.

Ferrari’s first V10 – by Osamu Goto for 1996 – was a 75º. Honda returned in 2000 with an 88º, which became a 94º in 2004. By 2005, all bar one had followed Ferrari’s by-then 90º lead.

BMW, bidding to catch up, broke the 19,000rpm barrier in 2002, as increasingly sophisticated software juggled ignition and injection on the brink of disaster.

Yet it was the drivability and reliability of the more established Ferrari that held sway until the V10s’ final year, when Renault’s 72º appeared with the greater stiffness – within the engine itself and between it and the chassis – required by a design preference for a rearward weight bias.

The 2.4-litre V8s that replaced the V10s in 2006 were much more proscribed: fixed vee angles (90º) and cylinder spacings, plus minimums for weight (95kg), bore (98mm), crankshaft centre-line height and overall CoG.

There were bans on variable inlets, reciprocating poppet-valves were made mandatory and fewer permitted materials were more tightly defined.

Renault’s 2001 comeback was with a 111º, hopeful of giant leaps in centre of gravity and aero advantage – but it tripped badly. For some, this slippery slope had begun long ago.

“Turbos were more challenging,” says Osamu. “More possibilities: fuel-consumption restrictions; different boosts, air/fuel mixtures and ignition timings; and less electronic assistance.

“It was very easy to break an engine. Naturally aspirated was more simple: optimising various minor tunings, and every year a 3% rise in revs and power.”

That’s easy for him to say.

Images: Getty

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