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Ilmor Engineering has developed an innovative 130bhp, 700cc, three-cylinder, five-stroke petrol engine that develops the fuel economy of a diesel engine without any of the emissions shortcomings.

The engineering firm, which has a long history working in motorsport and which was previously part-owned by Mercedes when it prepared its F1 engines, has developed the radical road car engine to showcase its engineering ability.

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Hasn't Mercedes already shown a similar concept in its F700 research vehicle, which produced 240 bhp from 1.8-litres and could get an S-Class sized car from 0-60 in under 8 secs but with 50mpg? I don't know if this works exactly the same as the DiesOtto engine of the F700, but its still the same principle of combining the best bits of petrol and diesel.

I also think VW and GM were doing something similar too.

 i wonder how much these engines cost, nearly 200bhp/litre. its over £40k to get one to that spec in the guise of an EVO FQ400. this sounds  the ideal sort of engine for a new lotus elise.

 

 

 I remember Autocar doing an April Fools gag of a new design of 3-cylinder boxer engine. The big piston on one side balanced the two smaller ones on the other. Always looked quite useful to me.

 Surely on the Ilmor engine the expansion cylinder would reduce the energy available to spin the turbo .

Uncle Mellow:

Surely on the Ilmor engine the expansion cylinder would reduce the energy available to spin the turbo

 

On the basis that turbo engines all have to use a wastegate to limit the positive feedback effect of the turbo, I'd say that there's more than enough spare energy available to power the compressor.

This idea isn't a million miles away from the way reciprocating steam engines (and steam turbines for that matter) have worked for a long time - typically three stages of expansion.

Also, re: 200bhp per litre, it's not really the same thing if the extra specific output is coming from the engine being far more efficient, as opposed to burning a lot more fuel (e.g. EVO FQ-400 etc) and therefore having to deal with a lot more waste heat.

I'm surprised Triumph hasn't hasn't had their 'triple' adapted for forced induction yet. If they can get 125hp from normal aspiration, it would be mind boggling to wonder what a hairdryer stuck on the end could produce from just 675ccm. Sticking that in a Lotus would make a fantastic British tie-up.