Octane additive

[1980RS]

How many here have had luck with Octane booster adding it to 91 non-oxy fuel. Did you find it worked with higher compression engines for good performance. I was thinking of putting on my 49cc Darts but I do not want to run the uber expensive fuel these days and others are telling me you can use like Klotz 4oz. and add it to a gal of 91 and come up with 101 octane fuel, but I have my doubts on this.

[ProPower engines]

If your running aluminum heads you can get away with higher then iron head compression but the tune must be perfect every lap or 1/4 mile or what ever but more compression needs good fuel.
And you may think about using E-85 fuel which will stand 11-1 with iron heads no problem but the fuel system costs may be out of your future budget as I am guessing this is a street machine.

if its a race car then just suck it up and get the best fuel your engine needs. When you look at the cost of pump gas today regardless of where you are the quality sucks and the blends are hit and miss at best as far as octane ratings go.

91 fuel is a mix or regular and premium fuels with some other additives thrown into the tanker and blended by sloshing about the tank to the gas station. Nothing really precise there so unless you have the test equipment to monitor the fuels you run my suggestion is keep the compression down to what you can afford to run it on.
Octane additives get costly over a short time and even after you try it and say I don't hear it ping anymore it can still be suffering from pre-ignition and you never hear it cause the pipes are loaded then stock anyway

[F-BIRD'88]

If all it really took to create high octane race gas from pump gas was a lil can of additive there would be no market for race gas.

Same with adjusting the required octane of a fuel for a engine just by a latter intake valve closing point.
DCR theory. There would be no need for high octane gasoline.

"Your mileage may vary".

When there companies claim x number of "points" of octane gain they are refering to 1/10ths of a octane number. 91 to 91.1 octane 91.4 octane improvment..
You can get the same effect by adding water to gasoline on a test of an engine that is knock limited.

[steve cowan]

How many here have had luck with Octane booster adding it to 91 non-oxy fuel. Did you find it worked with higher compression engines for good performance. I was thinking of putting on my 49cc Darts but I do not want to run the uber expensive fuel these days and others are telling me you can use like Klotz 4oz. and add it to a gal of 91 and come up with 101 octane fuel, but I have my doubts on this.

I have used this Nulon product before,does it work ? If you mix as per directions your spark plugs are orange in colour and you can't read them.
I want to test this on the dyno in a month or 2 with my 880 roller block, I have not done a final wet static compression check yet but will be over 11.1:1 and I want to run a shorter duration cam as well but we will see.
I want to see for myself if octane boost does anything and I want to test mixing a small percentage of MS109 with our 98 pump gas and see what happens.
I have read where people do not recommend mixing race gas/pump gas due to inconsistency, again I want to try for myself and see what happens.

20220716_134004.jpg

[blown265]

Steve, I use that Nulon ProStrength octane booster in my vintage aircooled single cylinder bike in summer- 10.0:1 SCR, 620cc, 32deg total advance, hemi chamber.
On our 98 pump fuel (US 93?), and a 35degC day, it will give a hint of detonation on a long ride. Adding the ProStrength version (Nulon has a couple of variants) takes care of any audible knock, though the pipe is straight through and loud, so take that into account. (plugs and domed forged piston shows no evidence of detonation)
Regards
Paulie

[Walter R. Malik]

When regular gas is $5.00 per gallon ... $12.00 per gallon for the fuel you actually need is not so expensive after all.

[RDY4WAR]

When regular gas is $5.00 per gallon ... $12.00 per gallon for the fuel you actually need is not so expensive after all.

It's more like that $5/gal is cutting into the budget for that $12/gal fuel.

[David Redszus]

When regular gas is $5.00 per gallon ... $12.00 per gallon for the fuel you actually need is not so expensive after all.

It's more like that $5/gal is cutting into the budget for that $12/gal fuel.

Nulon Octane booster consists of kerosine and MMT.

MMT has been used as a fuel addiditve for over fifty years. Some auto mfrs prohibit its use due to the
fact that MMT builds up on spark plugs.

The octane improvement is modest and dependent upon the base fuel to which it is added.

My preferfence is to use toluene or xylene available at any hardware store.

[Roundybout]

I’ve been using toluene to up the octane rating for my air cooled toys. I mix it with ethanol free 87 octane to get to about 95 octane. I tried xylene but it gave me some drivability problems when it was cooler outside (less than 80F). Plus it was harder to find the correct xylene as there are three different types and one is better then the rest octane wise.

Anywhere from $18.99-23.99 a gallon in my parts of the world. I get it in 5 gallon containers as it’s a bit cheaper that way. I’m probably paying a bit more than race gas but the availability of toluene compared to race gas near me works out.

[gunt]

we run alot of additive here , booted engines , never seen anything more than 23 oct increase , think 5 was the best but fuel is going so bad lately , i always advise build it to run n your fuel but not so it needs it to run , then you can add it and have a different map

[BillK]

You haven't mentioned what your final actual compression ratio will be ?? What engine ?? Carbureted or Fuel Injected ?

[1980RS]

You haven't mentioned what your final actual compression ratio will be ?? What engine ?? Carbureted or Fuel Injected ?

12.43 is final compression. My .040 358 SBC. Carbureted.

[Monza355]

Is Avgas an option ?

[1980RS]

Is Avgas an option ?

It was until 9/11 then big brother locked down all the small airports, can't get in without a pass.

[KnightEngines]

You haven't mentioned what your final actual compression ratio will be ?? What engine ?? Carbureted or Fuel Injected ?

12.43 is final compression. My .040 358 SBC. Carbureted.

E85 will be your friend.