Mazda MZR-R LMP2
Saturday, 24 May 2008 | Ian Wagstaff
Mazda's sports prototype engine

Rotary engine enthusiasts may have expressed concern with regard to Mazda North America's choice of conventional, four-cylinder motivation for its 2007 American Le Mans Series LMP2 programme. However, the move is a logical one, both for Mazda to be able to compete in an increasingly competitive category and also for the simple fact that the majority of road cars sold by the company have in-line engines.
That Mazda is serious, even on a reasonably limited budget, was indicated by its choice of engine supplier. Having spoken to around half a dozen builders, Essex, UK-based AER (Advanced Engine Research) was selected, the company already being known for its own Le Mans LMP2-winning engine. 'It was not just about power, it was about reliability and skill in this particular market,' recalls Marcus Haselgrove, technical director of BK Motorsports, who run the car. 'You are going to turn the engine on and then drive it virtually 100 per cent throttle for 12 or 24 hours - a different set of constraints to what many championships require.'
Another advantage of using AER is that it now has its own successful ECU and systems control operation in Life Racing. 'That's an important part of the interface these days, increasing the efficiency of the communication around the vehicle.'
Mazda's choice was shown to be a sage one when its Lola-chassied car posted eighth fastest qualifying time overall on its debut at the 12 Hours of Sebring in mid-March. It was, as Mazdaspeed manager Tod Kaneko pointed out, a mere 16 weeks since the project was started and the first engine had only run on the dyno during the first week in February.

Those involved are not giving away too much at this early stage, although a performance goal of 500bhp and 400lb.ft has been stated. Robert Davis, Mazda North America's senior vice president quality, research and development points out that the MZR-R is a fully bespoke race engine, but one that roadgoing technology could be applied to, particularly the 2.3-litre DSI turbo engine that is used in the US-market CX-7 and the Mazdaspeed 3 and 6. 'It was a difficult decision to make to not use a stock block but based on the level of competition from Porsche and Acura we realised that this would be limited.'
AER technical director Oliver Allan recalls, 'The initial brief was to convert the MZR to a race engine, but we saw some issues with that, the biggest being to get a dry sump into the engine in an economical manner. The compromise that we reached was to have a new design of engine, but one heavily based on the MZR. There are no common parts and, while the cams could be said to be of a similar design, they do not carry across. Davis says that development concentration will be on the direct injection, the pump itself, the compression ratios, the way in which the fuel/air is mixed and the way it burns and variable cam timing.

AER's goal was to beat the performance of its existing LMP2 customer engine, the 2.0-litre turbocharged PO7 I4, by between five and 10 per cent and, though definitive figures weren't available, Haselgrove reported being happy with the figures he saw even before the car was shipped to the USA.
The MZR-R, as it is known, uses a very lightweight casting and runs tight tolerances to save mass on reciprocating parts. The bore and stroke of the engine have been kept as close as possible to that of the MZR, and it was deemed important to use Mazda's roadgoing direct injection technology. 'That has been a good simultaneous engineering programme,' observes Haselgrove.
Some of the design team in Mazda North America were previously senior designers at Garrett turbochargers and so it's no surprise use is made of the same company's TR30R unit - an exclusive, bespoke design of variable vane turbocharger with a carbon fibre plenum manifold. This is a joint development between Mazdaspeed and Honeywell Turbo Technologies (Garrett's parent company). 'We had to optimise not only the packaging, but also the cooling and the ability to deliver the manifold pressure the way we needed it,' explains Davis.
The chassis chosen was the latest development of Huntingdon, UK-based Lola's endurance racer, the B07/40. It needed some performance improvements to take on Porsche and Acura but the choice was a logical one, particularly following improvements to the aerodynamic package that had been made during the winter.
'I don't think they could have made the four-stud engine installation much better if they had tried,' says Haselgrove. It is a stressed engine, although Lola still use mountings to the chassis to hang its own six-speed sequential gearbox. The new engine is smaller (512mm by 552.4mm) and lighter than the AER P07, Nicholson and Zytek engines used in other LMP2 Lolas. It has also been important that it fit chassis other than just Lolas as it is intended that the MZR-R be developed as a customer engine in 2008. As Haselgrove put it: 'The more engines that you have running, the quicker the R&D can be carried out.'
Another factor that was important to both AER and Mazda was that of expenditure. 'We have tried to maintain costs to a sensible level right through the programme,' says AER operations manager Robin Page. 'You've got to keep it at a sensible price so that you can get it into more cars.'
[x-head - Air of optimism]
As the car is to enter the whole ALMS series this year it was crucial to get it out in time for Sebring, despite only seven laps of practice time at Snetterton prior to the event. Nevertheless, there was an air of optimism on that first outing: 'The core engine is good and strong and we have got a lot of confidence that is it going to hang together,' predicted Page, just before the race. He admitted there were a few issues with ancillaries due to the lack of testing but, by the end of the event, his optimism proved right. Although throttle linkage and external oil ancillary problems delayed the car, the engine ran right through the 12 hours. In fact, the engine was running so efficiently that it was only using about 20 per cent of the oil cooler, which could have repercussions on future developments: 'The efficiency that the team has been able to deliver has been really good,' says Davis. 'If you can use a smaller oil cooler that means less frontal area and less drag...'

In summing up, Page is upbeat: 'It was pretty obvious from the first meeting that we could do something good together,' he says. 'Through Mazda we have had the opportunity, in an extremely tight time frame, to create this engine. There were many strategic decisions to make as to which elements we did and did not need to carry over and I think that what we, Mazda, AER, Lola and BK have got is an incredible achievement.' Certainly, the programme got off to a great start at Sebring. How it plays out over the forthcoming season will be interesting to see, but it certainly looks like the MZR-R is an engine with potential and one we'll be seeing a lot more of in the near future.


Mazda MZR-R specification
Displacement: 1998cc
Bore/stroke: 90mm x 78.4mm
Firing order: 1-3-4-2
Overall engine length: 512mm
Overall engine height: 552.4mm
Engine weight: 74kg
Cylinder head: cast aluminium alloy
Block: forged aluminium alloy
Connecting rods: steel
Crankshaft: steel
Valves: steel - four per cylinder
Camshaft: DOHCV
Lubrication: dry sump, oil tank in chassis
Boosting systems: Honeywell Garrett TR30R turbocharger with carbon fibre plenum manifold
Power: 500bhp
Torque: 400lb.ft
Redline: 8500rpm