110 octane !!

#1
Went by a local gas station the other day and seen that this gas station is selling 110 octane racing fuel at the pump for $8.50 a gallon. Never seen that before at any any gas station but probably never looked that hard cause too busy buying the cheap 87 non-ethanol octane. Does or has anyone ever tried this high octane fuel in a stock clone engine or is this fuel considered to be the same as alky? Don't know if i should try it it my stock predator engine or wait till i get my current hemi predator with ss valves installed built and see what kinda performance the results will be. Any comments anyone ? ?
 

rmm727

Active Member
#2
No need for high octane. Oxygenated fuel will help performance but the carb would need re-jetted. Neither makes sense on a stock engine.
 
#3
So there would no performance gain at all or the cost of the fuel it not worth it unless you mod your engine to run this high octane fuel to gain the extra hp. Or would it still worth the cost if you had a fully built engine ?
 

rmm727

Active Member
#4
Octane is resistance to detonation. The higher the octane, the higher the resistance to detonation, means harder to burn in the engine.
 
#6
Omg rmm727!!!!!! You do exist!!!!!! Someone who actually understands that putting 110 in your stock low compression engine gains you nothing!!!! Was starting to go crazy by myself in this world. Lmao!
And yes all the !!!!!'s were completely necessary.
 
#7
LOL, I hear ya outcrydrummer.... the other thing that drives me nuts are folks all excited abut putting "jet fuel" in the engine thinking it will be big performance gain or something. :eek:ut: :laugh:

Omg rmm727!!!!!! You do exist!!!!!! Someone who actually understands that putting 110 in your stock low compression engine gains you nothing!!!! Was starting to go crazy by myself in this world. Lmao!
And yes all the !!!!!'s were completely necessary.
 
#8
Thanks, to all the members out there. You learn something new everyday. Thought i knew alot but i am learning ALOT ! Love this OldMiniBikes forum , glad i joined in or on.
 
#9
By the way, I hope it didn't seem I was making fun of anyone here (hard to tell sometimes in just text)....'cause these are real common misconceptions. I know I have had plenty of them myself! (but I get to just call them a "blonde moment" and get promptly excused....he he he) :girl: :laugh:

Thanks, to all the members out there. You learn something new everyday. Thought i knew alot but i am learning ALOT ! Love this OldMiniBikes forum , glad i joined in or on.
 
#11
I run the 110 octane with Klotz oil in my CR-80 powered shifter kart only because Swede Tech who built the motor suggests it. I double checked and they make about 32HP out of a modified 80cc 2 stroke motor. Last time I bought the 110 octane I think it was $5.50/gallon. In all the mini bikes I run regular or mid grade with no problems. I am going to look for alcohol free gas this summer too so the insides of the carb do not get eaten up.
 
#12
i put vp racing gas in it once but that was before i milled the head and put in the f grind cam didnt seem to do much performance wise but it did seem to run better will have to try again .but in my professional opinion higher octane gas is better allows higher compression and more timing.
 
#13
Went by a local gas station the other day and seen that this gas station is selling 110 octane racing fuel at the pump for $8.50 a gallon. Never seen that before at any any gas station but probably never looked that hard cause too busy buying the cheap 87 non-ethanol octane. Does or has anyone ever tried this high octane fuel in a stock clone engine or is this fuel considered to be the same as alky? Don't know if i should try it it my stock predator engine or wait till i get my current hemi predator with ss valves installed built and see what kinda performance the results will be. Any comments anyone ? ?
We were replying to the thread starter in his question regarding a stock clone engine. Even with those stainless valves installed, unless you are increasing the engine's compression (milling the head, domed piston, i.e. decreasing the cc capacity of the combustion chamber to increase compression, you will NOT see any performance gains.


i put vp racing gas in it once but that was before i milled the head and put in the f grind cam didnt seem to do much performance wise but it did seem to run better will have to try again .but in my professional opinion higher octane gas is better allows higher compression and more timing.
Yes, exactly-that is what the higher octane is for. With a high-compression engine, you will actually need it to prevent knocking. We were referring to the common misunderstanding that using high octane gas in stock, mid compression engines (or in the case of older flat head engines, like Briggs & Stratton or Tecumseh, pretty low compression) engines) results in any type of performance gain-it absolutely and unequivocally does not. I think part what makes the high octane attractive to these people trying higher octane with the stock engines stems from the (mis)belief of "you get what you pay for" and higher octane being more expensive, it MUST be better . :eek:ut:

From the Wikipedia entry ON http://en.wikipedia.org/wiki/Octane_rating

"Octane rating or octane number is a standard measure of the performance of an engine or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating (igniting). In broad terms, fuels with a higher octane rating are used in high performance petrol engines that require higher compression ratios."

ALSO: "Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power."


Hope that clarifies it a bit... :thumbsup: High octane gas sure does smell good though..... lol. :laugh:
 
#14
I was told years ago that higher octane gas burns longer and cooler hence better for high compression. I do not know what makes an engine "Ping" when a lower octane is used but heard it is not good for an engine as it over heats it too.
Regular gas burns hotter than premium.
 
#15
I love the smell of C-12 in the morning. If you just had to run some kind of cool fuel in a mini bike, I would set the compression ratio at 18 to 1 and run straight methanol. Its cheap and you can't seem to run enough compression, the more the merrier. Just dump it out of the tank and carb when your finished having fun.
 

cxbra

New Member
#16
I run 87 octane in my bone stock engine. Ive run 91 octane and the engine actually felt like it lost a little of its spark! Throttle response just felt a little sluggish, like all the fuel wasnt burning. It might not have been as a big deal as im making it seem... But, you can only run as high of an octane as your engine will allow. Now, if my Predator was high compression, i'd definitely run 91 or higher because the engine would demand it.
 
#17
I was told years ago that higher octane gas burns longer and cooler hence better for high compression. I do not know what makes an engine "Ping" when a lower octane is used but heard it is not good for an engine as it over heats it too.
Regular gas burns hotter than premium.
As the other gents said octane is resistance to detonation. The higher the compression the more heat is generated.
Ping or knock is a result from too low octane fuel with too high compression.
The more compression the more heat....the more heat on lower octane you get detonation in the cylinder before tdc....which means your piston is on an upward thrust when the detonation happens trying to force the piston downward......yes very bad for the piston lol.

You will gear people talk about adding timing.....they are referring to initiating the spark further and further before tdc. A normal generic explanation is that it takes x amount of time for spark to get to the plug.....that x amount of time never changes....however as engine rpm increase the time for the piston to get from initiation of spark to tdc becomes shorter.....that's why you have ignition curves.

Anyways what I'm trying to say never really shines through what I attempt to type so I'm sure its as clear as mud right now Lmao.
 
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