Ignition advance

So I'm confused.

A mate has just bought and ignition advance unit for his (tuned) Fazer.
This got us onto the discussion that most engines have ignition retarded
to cope with low octane fuel.

But surely ignition should be advanced (earlier) to prevent low octane
fuel from detonating, or have a got my definition of advanced arse about
face?

TIA

--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 145 2.0 Cloverleaf 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk

 

It's about the speed of burn - the higher-octane fuel burns more
slowly, so the ignition thereof can take place earler, such that the
main 'bang' occurs at the optimal time. Lower-octane fuel will burn
more quickly, so the same advanced timing will make the 'bang' occur
too soon, causing knocking.

Pre-ignition, or pinking, is a different thing altogether.
HTH

--
_______
..'_/_|_\_'. Ace (b.rogers at ifrance.com)
\`\ | /`/ DS#8 BOTAFOT#3 SbS#2 UKRMMA#13 DFV#8 SKA#2 IBB#10
`\\ | //'
`\|/`
`

 

Bad form and all, but pinking is in fact another term for knocking,
which is different from pre-ignition. Sorry.

--
_______
..'_/_|_\_'. Ace (b.rogers at ifrance.com)
\`\ | /`/ DS#8 BOTAFOT#3 SbS#2 UKRMMA#13 DFV#8 SKA#2 IBB#10
`\\ | //'
`\|/`
`

 

So pinking isn't a close-up form of dogging?

 

The first answer, and it makes *perfect* sense. My thanks.

--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21 COSOC#3
Tyger, Tyger Burning Bright (Remove rust to reply)
116 Giulietta 3.0l Sprint 1.7 145 2.0 Cloverleaf 156 V6 2.5 S2
Triumph Sprint ST 1050: It's blue, see.
www.cuore-sportivo.co.uk