Premium gas

[Triumph]

<< << False! Burn rate is the exact difference in octane ratings. If the engine were designed to spontaneously ignite the fuel it would be a diesel! >>
(Tominator)

<<Eli is right. >>(Triumph)

No, Eli is not right. Higher octane gas burns SLOWER than low octane. Tominator is right. >>



The argument was whether octane rating comes from compression, or burn rate. And Eli is right, so I'm right. But yes, I agree that higher octane burns slower.




<< << Where did you here that? Most High performance V-8s from the mid sixties to 1974 can?t even run on the gas sold at stations today because the compression ratios where so high. >>(Tominator)
Correct.

<<This is because most of these engines used leaded fuel to reduce the engine knock at high compression ratios. Lead was the cheapest way of increasing the octane rating before it was banned in the mid 70's. >>
Wrong.

The reason older engines with less compression than newer ones detonate is mainly due to cam timing. Lead has nothing to do with it. There was low octane leaded gas, too.
Plus, they didn't quit selling leaded gas at the pumps until the late 80's or early 90's.
I've seen buildups on old small block engines that had 11-1 compression and would run on unleaded premium gas, due to the way it was cammed.

Look here to see the facts >>


Who said anything about older engines with lower compression ratios? We're talking about old engines with high compression ratios. I'm not really sure what you're saying....Lead was added to gasoline to raise the octane rating and thus prevent knocking.

 

[Tominator]

<< Lead was added to gasoline to raise the octane rating and thus prevent knocking. >>



That was only part of it's purpose, but lack of octane was never a problem in older engines. There was a scare in the late 70s when gas prices skyrocketed and pollution regs threatened an end to high octane fuels, but technology caught up with the demand and then the only concern was the lubricateing properties of lead as I stated.

 

[Pacfanweb]

Original statement:
<<<< The higher the octane rating, the slower the burn rate of the air/fuel mixture. This means that with higher octane fuel, you can run higher compression and/or advance the ignition timing, both of which can result in more power (depending on the motor). >>

What Eli said:
<<That is incorrect.

The Octane rating has nothing to do with how fast the fuel burns. It has everything to do with how much pressure(compression) it can stand before it spontaneously ignites>>

What Triumph said:
<<The argument was whether octane rating comes from compression, or burn rate. And Eli is right, so I'm right. But yes, I agree that higher octane burns slower. >>

How do you figure the argument was whether octane rating comes from compression from "The higher the octane rating, the slower the burn rate of the air/fuel mixture."??
That is a correct statement.
Look above at what Eli wrote. He is dead wrong. Octane rating has everything to do with how fast the fuel burns. Higher octane burns slower.
How much compression the fuel can stand before it ignites is saying the same thing. If it is not as flammable, (e.g. burns slower) then it can stand more compression.

I think we're ultimately all saying the same thing here, though.

 

[Triumph]

<< I think we're ultimately all saying the same thing here, though. >>


I think so too, cause it's getting too hard to decipher what's wrong with each other's statements.

 

[Tominator]

True, we just all started using simplistic sentences about a complicated subject...

 

[Evadman]

A station down the street from me sells 110 octane leaded fuel, and 101 racing fuel (unleaded) Not bad

I thinnk besides my above pointless coment, I have little to add on this discusion besides the fact that this is one of the first threads I have read that did not degenerate in to personal attacks

 

[Pacfanweb]

<<A station down the street from me sells 110 octane leaded fuel, and 101 racing fuel (unleaded) Not bad >>

Cool that you can get the 110 at a gas station. I get 114 at the track, but you can't find leaded racing gas at any stations around here.

I mixed up some 114 for my chainsaw the other day.....man, that stuff smells good when it burns.