Constant legislative, emissions, fuel economy and consumer pressure are driving manufacturers toward producing more efficient engines with complex control. Many of these new engines have benefited from optical research engines to develop advanced fuelling and combustion strategies. Existing optical research engines have been shown to be limited by speed, degree of optical access, robustness or ease of use. Lotus Engineering has designed, developed and validated a new optical access single cylinder research engine. The optical access is achieved via a combination of (1) fused silica cylinder, (2) pent roof combustion chamber and (3) optical piston crown (sapphire). The optical techniques to be used with the new engine are (1) phase Doppler anemometry, (2) high-speed imaging and (3) laser induced fluorescence (LIF). The engine is now fully commissioned and is capable of being motored or fired to speeds greater than 5000 rpm and pressures of 60 bar.