FEATURE NISSAN VK45DE wThe competition
The Nissan VK45DE has two competitors in LMP2. Engine Developments has made use of BMW’s V8 – a 4.0-litre in road going form – for the Judd HK. The limitations of the Honda range have forced HPD to use a 2.8-litre V6, twin turbocharged for racing. At the start of the season, the five per cent air restrictor advantage given to the naturally aspirated engines of the lighter, cost-capped ORECAs and the Zytek gave
them a distinct advantage. After Paul Ricard, the ACO gave the HPDs a restrictor break of 1.2mm, increasing it in size from 28.1mm to 29.3mm. Prior to Le Mans it was also felt that the Judd’s restrictor should also be adjusted to 42.4mm. In qualifying for the 24 hours, an ORECA-Nissan still proved quickest but Strakka’s HPD was next, just over a second adrift, while the fastest Judd was 1.7 seconds behind.
Based on a standard Nissan road car block and heads, the LMP2 engine uses bespoke crank, rods, pistons and intake for maximum efficiency
external and internal parts, under Nissan design, for the engine. The new regulations limit what can be done, and every new part has to be homologated by the ACO. Some work has been done on the cylinder block in terms of crankshaft retention, including different main caps. Likewise, there has been some work to the standard cylinder head and the valvetrain, but a large amount of the parts, including the crank, rods, pistons and the intake system are bespoke to LMP2 regulations. Naturally, it is also dry
“we don’t know where this is heading. It may lead to other future programmes”
sumped, unlike the road car version. Because of the regulation air restrictor, its maximum power is 450bhp and its maximum torque 579Nm. ‘It’s based on a standard road car engine, so is a very
conventional V8,’ admits Manchester. ‘What we have done is to make the engine very efficient.’
Areas of compromise He also points out that performance comes at a cost so, to keep under the price cap, LMP2 engine manufacturers have to compromise. ‘Reliability is of paramount importance in any sportscar engine,’ he says. ‘It is only when this is achieved that the company can look at the performance.’ In the case of the VK45DE, compromise has been achieved
through manufacturing techniques which have led to slightly heavier parts. ‘They could have been made lighter, and the gear train could have been different,’ adds Manchester, pointing out that a Zytek 3.4-litre ZG348 LMP1 engine weighs 125kg, while the Nissan version tips the scales at just over 150kg. That may be predominantly because it has a production-based cylinder block and heads, but there are plenty of parts in the engine that could be made lighter, were it not for the cost cap.
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www.racecarengineering.com • August 2011
Engine specialists have been forced to use production-based blocks. Judd opted to use the BMW V8, 4.0 litre in road going form.
The engine has shown up well on the test bed, and now on
the track too, but Manchester believes there is still much room for further improvement, especially with Zytek and Nissan now working on joint development programmes. ‘I think we have only just scratched the surface of this engine for LMP2. We are now starting to look at various different areas of development – the type of work that you would do on any racing engine. We are learning about it. Every engine has its own idiosyncrasies and you have got to understand them. As we do that it will get better and better.’
Nissan was last seen as part of a full factory programme at Le Mans in 1999, yet there had been times during the 1990s decade when the Japanese company had been amongst the favourites to win the 24-hour race outright. So, does the company’s re- entry into this style of racing herald another, future attempt at sportscar racing’s ultimate crown? ‘It is the very early days of what already is a strong
partnership,’ replies Manchester. ‘We don’t know where this is heading. It may lead to other racing programmes in the future, but for now our main focus is to make this engine the best in the class.’ Whatever the future holds, it indicates a new approach, as this is the first time a NISMO power unit has been built outside Japan by another engine manufacturer.
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