~Octane Rating..

[LeeSmith]

is there a limit on the fuel octane rating an engine should be run on?

i mean for example if someone were to boost there petrol to 110RON would it do the engine more harm than good or is it a case of the higher the rating the better???

maybe a silly question but it may be a case of too much octane and bang, bye bye engine......

thanks in advance

 

[Mr GTiR]

too much octane will burn out your piston liners but i'm not sure what is classed as 'race' fuel ?

 

[beast14]

i would like some advice on this topic too.........cause when i'm racing i sometimes use tolouene and also throw in a bottle of 108exteme octane boost.........this seems to work pretty well for me!!!...........but as was stated if the rating is too high i might be damaging my pistons??!!

 

[paz]

something I read somewhere said that fuel with an octane rating that high will fuck up your oxygen sensor as well :shock: do a search on the forum, it'll be about somewhere.... think it was in one of your topics beast

paz

 

[Keira]

if the octane ratings too high i think it burns to hot and causes damage.

there was a good link on the erl aquamist site, dont think its still on there though.

 

[Fast Guy]

I'm not sure on this, but octane is resistance to detonation, so to me I can't see how too high would damage your engine, unless it's the fuel/octane booster you're using that completely changes the burn characteristics of the fuel. Too little octane and you'll know about it :shock:

If you're going that high over normal, you'd be well advised to get a remap. Octane doesn't give you power, it gives you the ability to run higher compression, more advance,etc. ie tune for more power before you get detonation.


But I may be wrong :roll:

 

[antilag]

im running 118 in mine and was told the engine will not det with this stuff in

 

[Keira]

The thing i rembered was this bit...

10. What is the maximum alcohol/ water ratio I should use?
No more than 50%, otherwise you will increase the cylinder temperature rather than reducing it. Beyond that ratio, onset of detonation is more likely. Methanol freezes at -96 deg. C, 50% mixture will stop the mixture from freezing at around -40 deg.C.

that might only apply to using methanol (oct of 113 8) ), the link that used to be there is no more .

I take that it means the ratios of whatever you use to raise the octane rating with the fuel will be the same as with water, have to be right the ratio, not the actual rating of the substance your using....I Think :roll:

 

[LeeSmith]

cool, so in other words dont fill your tank up with octance booster only

Cheers guys

seems safe to run at about 110....

 

[Fast Guy]

Keiron,
Hope I haven't misunderstood what your saying
that link is refering to the ratio of a water and methonal mix together, saying don't use more than 50% methonal. Methonal is a fuel and if you add too much you are changing the burn characteristics of the whole fuel mix to the point where it will start burning more like methonal than petrol. If you add more water than meths, chances are you'll get to a point where you just start killing power as water doesn't burn, where methonal does.

An RAF example of water/meths.

NATO S–1744
AL–28
METHANOL/WATER: 44/56

Composition: AL–14, 43.8 parts + WTA, 56.2 parts (by volume)
Characteristics: Density at 15°C … … … 0.941–0.945 g/cm3

The specification includes tests for acidity and total solids.
This product is a clear colourless liquid.
Uses: Thrust augmentation fluid in certain aircraft turbine engines.

Stores Numbers:
NATO Stock No Nominal Size Navy Army RAF
6850-99-220-2292 200 litre – – – – 34B
PSN: Methanol
UN No: 1230
UN Class: 3, Subsidiary risk 6.1
Packaging Group: II 5

 

[Keira]

Yep you're right it is for water injection, got myself confuzzed :roll: but wouldn't the same thing happen if it was in the fuel, i.e you were using an additive at to high a quantity :?: thinking about it, its nothing to do with the octane rating but the ratio of the mix, like you say altering the burn characteristics.