Crystal-clear scrutiny of what's happening beneath the bonnet

The glass cylinder lets engineers analyse combustion efficiency. Photo / Supplied

Lotus uses a glass engine to test combustion patterns.

More accurately, it is an engine with a single glass cylinder and piston that lets engineers see what is happening inside the motor as fuel is squirted in, is ignited by a spark, the piston is fired down the bore and spent gases are forced out on the upstroke.

Lotus is involved in engine research for a variety of clients and says this is the most efficient way to examine the process.

Laser diagnostic techniques are used to view and measure what's going on because the 5000rpm maximum running speed is too fast to monitor accurately with the naked eye.