Premium? Unleaded? Both? Neither?

[Yankee]

ran my bike on LRP for a year+
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!!!!!!!
think of the $$$$$$$$ i've saved!!!!!!
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!!!!!!!

nothing bad happened (that i know of yet?)
can't kill a kwak engine (knock on my head or wood)

[kypez]

ran my bike on LRP for a year+
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!!!!!!!
think of the $$$$$$$$ i've saved!!!!!!
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!!!!!!!!!

nothing bad happened (that i know of yet?)
can't kill a kwak engine (knock on my head or wood)

Well, the thing that you would have stuffed up is your catalytic converter. It would have become useless after about 2 kms of your engine running on LRP. And now that you are back on unleaded, you are realeasing an extremly high level to toxic gases. Not the best thing you could have done for the environment or for the person behind you.

Should get a new cat.

Also how did you save money using LRP since it is 3 cents a litre dearer than unleaded?! Or am I not reading proporly between the lines... hmmm

[Yankee]

correct me if I am wrong, but.....
my bike (i believe) has a pre-catalytic converter and also a "real" main catalytic converter. the "pre-" is just a small-size 3-way converter installed in the joint pipe of the exhaust, which is just a punched piece of stainless steel, with the surface coated with alumina and platinum (and some rhodium) as catalysts (purifies CO, HC, and NOx to a certain extent).....
the Main Catalytic converter is again just a piece of punched steel with predominately platinum and rhodium applied, but also has a honeycomb structure made by a bending of a corrugated sheet and flat sheet of stainless steel into a spiral of increasing diameter (lousy way to describe it, but it looked weird) this one is located in the main first chamber of the silencer (muffler, can, pipe, whatever you call it)
ANYHOO..... neither would of been effected by the LRP burning in the system (atleast what i could research/find) due to the tempurature and pressures associated with the density and fluid flow of the transfer of the CO, HC, etc.... at the time of conversion......
anyway, this is what i heard about my bike...... and sorta saw when i modified my exhaust system! So, yeah I'm polluting the environment anyway........
and the LRP in my neck of the woods costs a few cents a liter cheaper than the ultimate (the only two i concidered for the bike, WHICH is a whole nuther story as well... ... basically LRP has a high RON rating like the Ultimate, and has soft.... eh, nevermind, too long to type....)
BTW, this is just all my thoughts and opinions, i am no professional anything..... (Bullshitter maybe?)
so don't try this at home.

[kypez]

what i've read and been told is that cats last 2-5 kms running on non unleaded fuel. They dont just become less effective, they become ineffective.

Yeah, LRP is cheaper than ultimate and even premium... my bad, forgot what forum i was on for a second and spoke about REGULAR!!!

[Smitty]

hahaha
yankee and kypez
ya both wrong!
LRP does NOT damage cats
nothing in it to do so....
the lead in leaded petrol killed cats as it coated the
monolith structure in the cat. which is the reason
Leaded petrol is not available (plus the lead is a poison)

LRP has basically got nothing in it..its a crap petrol, equal to the old
'standard' petrol (low octane) with NO lead
some LRP does have manganese in it to try and prevent
valve seat erosion (not really successful though)
use as much LRP as you like but the bike will
run crap as the octane level is too low for most modern bikes
(I use LRP in the mower mixed with 2 stroke oil..works fine
in the Victa)


cheers

[kypez]

was wondering about that... since it is lead replacement and leaded fuel is illegal.

Though other components of the fuel are said not to bed good for a cat either.

[Steve_TLS]

I'm not picking on you, it might look like it though There's a bit of misinformation there that's all.

Nice. But they should be careful as engines designed to run on 91 octane might need valve protection with the extra "energy" produced by the high octane fuel.

Also, I wish we got 100 octane like some in america. That would let us bump the compression even higher without messing the heads too much!!

The only time you need valve protection is when using an unleaded fuel in an engine designed for leaded fuel. The lead while used to increase the octane also acted as an upper cylinder lubricant and help valve seats, nothing to do with the energy content. You're engine will actually make more power on the lowest possible octane without detonation. It ignites more easily and burns faster. Higher octane fuels are harder to ignite (hence the high octane, resists detonation) and is a slower burning fuel.

The Americans use a differnet method to come up with an octane number there is RON, MON and PON read here and look at the chart (we use RON)>> http://www.btinternet.com/~madmole/Refe ... ONPON.html

The reason we use Premium is to avoid engines from pinging, ie the fuel to self detonate in the cylinder without spark due to temperature and pressure. The result is that it can damage your valves and the cylinder itself by combusting on the wrong stroke.

Don't confuse pre-ignition (ignition before the spark plug fires) with detonation / knocking / pinging / pinking. Detonation always happens after a spark induced burn.

Here's a good read on pre-ignition and detonation. Read all 8 pages, it's good. >> http://www.streetrodstuff.com/Articles/ ... etonation/

[kypez]

I'm not picking on you, it might look like it though There's a bit of misinformation there that's all.

The only time you need valve protection is when using an unleaded fuel in an engine designed for leaded fuel. The lead while used to increase the octane also acted as an upper cylinder lubricant and help valve seats, nothing to do with the energy content. You're engine will actually make more power on the lowest possible octane without detonation. It ignites more easily and burns faster. Higher octane fuels are harder to ignite (hence the high octane, resists detonation) and is a slower burning fuel.

The reason we use Premium is to avoid engines from pinging, ie the fuel to self detonate in the cylinder without spark due to temperature and pressure. The result is that it can damage your valves and the cylinder itself by combusting on the wrong stroke.

Don't confuse pre-ignition (ignition before the spark plug fires) with detonation / knocking / pinging / pinking. Detonation always happens after a spark induced burn.

Here's a good read on pre-ignition and detonation. Read all 8 pages, it's good. >> http://www.streetrodstuff.com/Articles/ ... etonation/

Couple of things. You CAN damage valves by increasing operating temperature and using high octane fuel that DO increase operating temperatures. Will try find my uni notes somewhere and scan them.

And your comment on Pre-ignition and Detonation is duely noted. My apologises for the misinformation.

(note to self, stop posting late at night to avoid these mistakes!!!) Thanks for the correction, also very good read, that link is.

Have heard about different measurement methods... Havent read much about that, thanks again for the link.

[Steve_TLS]

Couple of things. You CAN damage valves by increasing operating temperature and using high octane fuel that DO increase operating temperatures. Will try find my uni notes somewhere and scan them.

If you find those notes, I'll be interested in reading them. I thought running higher compression increased the pressure and temperature and dictated a higher octane fuel. Not the fuel was responsible for the increase.

(Unless we're talking about the denser oxygenated fuels that pack more punch per litre that come in the highest octane. Then I agree that more power = more heat, but it's not the octane doing it, it's the extra energy in it)

[zbeast]

LRP has basically got nothing in it..its a crap petrol, equal to the old
'standard' petrol (low octane) with NO lead
some LRP does have manganese in it to try and prevent
valve seat erosion (not really successful though)
use as much LRP as you like but the bike will
run crap as the octane level is too low for most modern bikes
(I use LRP in the mower mixed with 2 stroke oil..works fine
in the Victa)


cheers

Mobil LRP used to based on the Synergy 8000 and had a 98 octane rating but was cheaper than the 8000 so I was using it in my ZXR250. It must have been costing them too much because they dropped it back to either 93 or 95 before all the servo's eventually phased LRP out.

My local Caltex has a sheet at the counter which lists the fuel that they sell, when it was last tested and what octane result it was. When they were selling LRP it was usually closer to Vortex than the normal unleaded even though it was based on the normal stuff. I think the other additives that were used to stop valve recession in older cars also helped bump the octane rating.

If you want some really high octane fuel get friendly (no not that friendly ) with someone who races in the 125 or 250 gp class and see if you can get some Elf or equivalent off them.

[Smitty]

The only time you need valve protection is when using an unleaded fuel in an engine designed for leaded fuel. The lead while used to increase the octane also acted as an upper cylinder lubricant and help valve seats, nothing to do with the energy content.

Petrol is a mixture of compounds of carbon and hydrogen called hydrocarbons; most of the hydrocarbons in petrol are alkanes. In modern engines, the petrol vapour-air mixture is highly compressed before it is sparked, in order to get the maximum energy from the burning fuel. But, some hydrocarbons tend to ignite under pressure before they are sparked, so that the engine runs roughly; this is known as "knocking or pinking". Branched-chain alkanes tend to resist this pre-ignition better than alkanes with unbranched chains. Alkanes and fuel mixtures are given Octane ratings depending on their knocking tendency. 2,2,4-trimethylpentane (which contains 8 carbons and so is an isomer of octane) has an Octane rating of 100; heptane has a rating of 0. The Octane number of a petrol is the % of 2,2,4-trimethylpentane in a mixture with heptane that has the same knocking characteristics as the petrol under test.


In 1922, an American called Thomas Midgely (who also invented CFCs) found that if tetraethyl lead, Pb(CH2CH3)4, was put into petrol, particles of lead and lead oxide PbO are formed on combustion. This helps the petrol to burn more slowly and smoothly, preventing knocking and giving higher Octane ratings. 1,2-dibromoethane is also added to the petrol to remove the lead from the cylinder as PbBr2, which is a vapour and removed from the engine. (This is how lead is released into the environment from leaded fuels).
why?
Lead tetraethyl (left) is a lead atom bonded to a tetrahedral arrangment of ethyl groups. Thus, the molecule can be thought of as a metal atom surrounded by a hydrocarbon cage. The C-Pb bond is quite weak, and in the hot environment of an internal combustion engine it fragments producing lead and C2H5 radicals which can help propagate the combustion process by radical reactions.
and so....
Lead does have an effect on the energy content of the petrol
marginally. However it was primalrily included to allow increased compression ratios (and MORE power) in the internal combustion engine

hth

cheers

[kypez]

But, some hydrocarbons tend to ignite under pressure before they are sparked, so that the engine runs roughly; this is known as "knocking or pinking".

I'm so confused. This is what I had said eariler but the article link has a different meaning for it.

[mike-s]

thanks for that Smitty, but one thing that came to mind is that it's a bit funny that both of Thomas's major (presuming he did other chemistry things) inventions (tetraethyl lead & cfc's) were both outlawed for environmental reasons.

[Steve_TLS]

But, some hydrocarbons tend to ignite under pressure before they are sparked, so that the engine runs roughly; this is known as "knocking or pinking".

I'm so confused. This is what I had said eariler but the article link has a different meaning for it.

The spark starts a burn and the pressure and temperature rises in the combustion chamber, this can cause the spontaneous combustion of the rest of the mixture. Detonation always happens after a spark initiated burn. (But the out of control burn wasn't started directly by the spark)

If it ignites before the spark, it's preigniton, but preignition is hard to get to happen in the latter stages of the compression stroke, it will happen much lower when the pressure is low.

[Smitty]

The spark starts a burn and the pressure and temperature rises in the combustion chamber, this can cause the spontaneous combustion of the rest of the mixture. Detonation always happens after a spark initiated burn. (But the out of control burn wasn't started directly by the spark)

If it ignites before the spark, it's preigniton, but preignition is hard to get to happen in the latter stages of the compression stroke, it will happen much lower when the pressure is low.

correct Steve
and this is where combustion chamber design (and compression ratios)
enters the picture in this whole topic. Even the question whether we are talking alloy vs iron engines needs to get raised.
Cast iron engines (inc heads) can take more preignition (or pinging)
and detonation from fuels than alloy heads/engines. The alloy tends to get
pitted from preignition or detonation ..as much as ending up with a hole in a piston...

cheers