cold fuel?

[carl_w]

How much advantage would chilling the fuel actually confer? Surely the power of an engine is limited by the amount of air you can get into it; you then just squirt in the appropriate amount of fuel to get the mixture right. The ratio of air:fuel is 14.7:1 stoichio, so the air temperature makes a far bigger difference than the fuel to the overall charge temperature.

For sure, you could get the chilled fuel into the tank a little bit quicker than at ambient, but that's probably not even a couple of hundredths of a second advantage.

Anyone done the maths?

[carl_w]

Got a link to an article?

[carl_w]

Hmm, 310 kelvin (ambient) versus 296 kelvin (chilled). I still can't see there being a lot of difference. It's not like we're talking about super-chilled fuel here.

[carl_w]

That's canny john, but I actually started this thread to understand what the effects of the cold fuel were. Clearly if the rules have been broken, then they should be punished. However, if the cold fuel confers little or no advantage it would suggest that the breach was accidental rather than deliberate.

[carl_w]

Scuffers said:

it's basic physics, if you evaporate fuel into air, then the air will be cooled by the exaporation of the fuel

Yes, evaporative cooling is well understood. However, are you telling me there's a significant difference in the cooling of the inlet charge through evaporative cooling between case (a): fuel injected at 310K, and (b): fuel injected at 296K?

[carl_w]

Scuffers said:

and quoting tems in K is a bit missleading when the evap point of petrol is some 340-350K, at if the fuel is at 310K, it's only some ~30K of it's evap point (in free air which of course an engine intake s not). dopping this 10 degrees is some 20% difference....

Surely this is the wrong way round? From what you're saying, hotter fuel is more likely to evaporate (or evaporate more completely) and hence the charge cooling effect would be greater. Surely the cooling effect is just a latent heat issue, which means that it's only the state change that needs to be considered, not any temperature changes that have gone on beforehand in the liquid state?

Edited by carl_w on Wednesday 24th October 19:52