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Single Cylinder Optical Research Engine

Single Cylinder Research Engines

Single cylinder combustion research supports the development of new combustion and engine design without the investment in multi-cylinder prototype hardware for the benefit of faster and lower cost validation of new concepts. 

This range of products and services can be delivered in many ways. We can carry out research at our engineering centres for clients or provide our research engines with full support and training packages.

Lotus is a leading expert in combustion and Homogeneous Charge Compression Ignition (HCCI) and we develop and apply that knowledge using unique single cylinder engines that facilitate cutting edge research.

The Lotus Active Valve Train enables fast, flexible and low cost research into new combustion and valve train design and has benefitted numerous major vehicle manufacturers as well as research institutions globally.

Our single cylinder combustion research systems include:


To support our client's combustion research, Lotus offers the advanced Single Cylinder Optical Research Engine (SCORE) that has a glass cylinder and piston that enables the use of laser diagnostic techniques to visualise and measure combustion phenomena in the running engine.

This product allows real-time images of various phenomena inside the cylinder such as fuel spray dispersion and flame propagation to be captured so that research teams can develop new understanding of combustion and the reduction of fuel consumption and emissions.

The Single Cylinder Research Engine operates at real engine loads at speeds of up to 5,000 rpm while providing full access for the use of optical diagnostic techniques with minimal disruption to the geometry and functionality of the engine. The Single Cylinder Optical Research Engine can be used in conjunction with the Lotus Active Valve Train system for greater control of the combustion process.

In addition to supplying the engine as a product, we offer support and training as well as in-house research for clients using our own engine.


  • Extended piston with stationary 45 degree mirror and sapphire piston crown window
  • Removable glass cylinder forms the optical bore
  • Upper crankcase with hydraulic platform for mounting / release of optical components
  • Quick release liner to enable easy and rapid maintenance
  • Accurate 'real engine' geometry
  • Lower crankcase containing crankshaft and primary and secondary balance shafts
  • Operates at real engine loads and speeds up to 5,000 rpm


Various phenomena can be investigated using optical diagnostic techniques.

  • Flow velocity can be measured using Particle Image Velocimetry (PIV)
  • Flow velocity and particle size can be measured using Phase Doppler Anemometry (PDA)
  • Concentrations in spray fields can be measured using Laser Induced Fluorescence (LIF)
  • Soot concentrations in unsteady flows of complex geometry can be measured using Laser Induced Incandescence (LII)
  • Combustion, flame growth and propagation can be measured by high speed imaging