Dodgy diesel-heads to the bridge please

[Dave Plowman (News)]

The 'mixture' can be mapped for any load and engine speed.

My guess is it's precisely to give more 'power' that the emissions are so much poorer in practice.

[The Natural Philosopher]

Exactly.

I don't see what point you are trying to make, other than you are unable to understand technical english...

[Vir Campestris]

After you queried my question I went back and read your original again. Then I found the bit you added for Fred, which makes it all clear.

So injection time does vary?

Andy

[Fredxxx]

Just correcting your mistake where you said "shoving fuel in at the point where peak temperature and pressure coincides with TDC" simply isn't true.

That's all.

[The Natural Philosopher]

Of course. All I was saying is that getting the biggest bang with the hottest temperature and highest pressure at pretty much TDC is what makes diesels efficient and what makes NOx as well.

[The Natural Philosopher]

It depends on how you read it. And what exact meaning you ascribe to 'where'

And how stupid you think your readership is.

I.e. the point you make "Fuel takes time to burn, it doesn't spontaneously explode when "shovelled in" or even "injected"." is something I assume everybody knows already.

Ergo 'shoving fuel in so as to make peak temperature and pressure coincides with TDC' obviously implies some advance.

My only mistake was to substitute 'so as to', with 'where'.

[Dave Plowman (News)]

The length of time the injectors are open for is the way most control fuelling.

[Vir Campestris]

That's duration. I meant as in the timing before TDC when the fuel flow is constant.

Andy

[Dave Plowman (News)]

Right - so injection timing. Injection time is duration.

IIRC, most modern systems have more than one timed injection per cycle. Only became possible with high speed electronic injectors.