My 32 coupe has a 60 over 401/425 cammed nailhead in it. It’s not radical by any means but it’s not stock. Normally I run just the regular piss water gas and I like to add an octane booster when the need arises. Buying premium all the time gets expensive as well as it seems a waste for my driving purposes. My wife’s 40 pickup with hot V6 may need it more often than that once in the road. I had a couple cans of the Pennzoil 104 octane booster and that worked really well but I can’t seem to find that anymore. So - what do you guys use/recommend?
Boosters are unreliable at best, even the good ones vary a lot in result depending on what the refinery mixed together and call fuel on that particular day. You'd be better off figuring out a permanent solution.
@TomT Use Toluene! Toluene is a pure aromatic hydrocarbon solvent often referred as methylbenzene (C7H8) It has a RON octane rating of 121 and a MON rating of 107. Formula 1 cars ran on 84 % toluene but needed to have Toluene heated to 70c to help ignition [They would've run 100% but needed other properties to keep it legal]
The way I’ve always understood it was that the octane rating is a detonation rating and using higher octane than what is required to keep the detonation in check is a wast of money. I’ll assume your tune is on point but if not a timing change may get you were you wouldn’t need the extra octane.
What would be the need that would arise for this? Are you getting detonation (preignition) under load?
For clarity, in the US we use the R+M/2 method for measuring octane. I have no idea why we do this. So this would be (121+107)/2, or US 114 octane. This is what it compare to with US pump gasoline.
AAA says national average gas prices this week for regular and premium are $3.288 and $3.926 respectively. That's a difference of 63.8 cents/gal. For a 15 gallon tank, that's $9.57 more for premium. How much is a can of octane booster?
Detonation is "Auto Ignition" [not to be confused with pre-ignition] When the Air/Fuel mixture is exposed to temperatures higher than the Auto ignition temp it will self ignite. Rapid increase in cylinder pressures will cause this [this is how diesel engines ignite] The higher the Octane, the higher the Auto ignition temps and "anti-knock" properties [going the other direction is Cetane] You cannot "tune" detonation out of an engine [only reduce the destructive energy] . You need to reduce detonation mechanically by lowering cylinder pressures [compression or cam timing] or raise the auto-ignition properties of the fuel. Ignition advance is "timing" the flame propagation for maximum cylinder pressures. Retarding the ignition only reduces energy destroying pistons [delaying flame propagation until the piston is further down the bore ] We're played around with blending fuels on Diesel engines. You can safely add 30% Gasoline to diesel fuel and it runs OK [less power due to less BTU content] The engine doesn't "detonate" because of injector timing. But add any fuel to the intake runners will eventually destroy a diesel engine [spraying high Cetane diesel fuel is the worst offender] Incidentally the 30% Gasoline 70% Diesel blend is the recommended "winter blend" in a Mercedes handbook.
The .mil used to have "multi fuel" Diesel engines in the Deuce and a halfs. They could run just about anything. Somebody said they had run a mixture of gasoline and 90 wt gear oil, when that was all they had. Smoked a lot, but it got the job done. Modern diesels are a lot more picky, I'm told.
What's your compression ratio and your duration and LSA numbers on your camshaft? You're just using a "crutch"! Look into aviation fuel.....may be cheaper AND better than off the shelf "booster". (You know one can of that stuff in a tank of gas is like "peeing in the ocean" for all the difference it makes. It will take SEVERAL cans to raise the octane a point or two) Gotta be a better option. 6sally6
With what the OP posted about his engine I do not understand why it would require a booster. Run 93 pump gas and go. Still cheaper then buying bottles of booster .
I have one street engine right on the edge running just premium, could you explain how the Royal Purple cocktail mix works
The blends needed should be measured in percentages ,not "add a bottle to a tank" Aviation fuel is great and "leaded" [the lead content makes it illegal on-road] Here is NZ AvGas for our racecars is cheaper than normal pump gas because there is no "Road User Taxes" factored into the price. We need a competition license to purchase AvGas Toluene is a unleaded aromatic ,so it can be used with O2 sensors and won't poison Cat Converters. We shouldn't get too off topic here! A diesel engine will run on pure 90wt [if pre-heated to lower the viscosity] This is similar to "bunker oil" used in ships We did over 100,000 miles in an O/T Mitsy Diesel SUV on waste trans fluid / waste engine oil blended with gasoline.
I have never used it but this stuff is supposed to be pretty good. Pricey though. If your using the Professional grade a little goes a long way according to the mixing chart. https://boostane.com/
I'm not sure that SAFELY works on that blend. You now have a mixture with the volatility of gasoline and the BTU content of Diesel. I actually saw a safety film on this back in the 80's.
Toluene! "The Breakfast of Champions". I have a buddy who has a chemical supply business. This is a partial can leftover from when I used to have a turbocharged daily driver.......
I use VP Optimus, 1 can for 10 gal. The porcelain on the spark plugs will have a slight reddish tint to them, I ran a engine with 14-1 on street / race. I mixed the VP with 93 & 94 pump gas, before covid prices , @ local parts store , a Single can was $18 -28 a can, I would buy cases @ a time witch knocked price down to $10 a can , still cheaper then Race gas by $5 a gallon., my race rod was 10 miles to a gallon , Not normal driving conditions, I prefer the Aviation fuel ,Its becoming harder to get unless you go to a independent mom and pops airport/ air field,( FAA issues). The air field was a self severed pump 24/7 for over 30 plus years . New owners realized that more people were using aviation fuel ( Racer's) then air plane sales , So they did away with self serve , & If No plane present, they would charge a Extra $2 a gallon, there Fuel sale took a big hit , Over 80 percent of their fuel sales were non-aviation related. There is No easy way to check octane . According to the VP its done with Heat & pressure in a lab ,,, I was thinking you could use a Specific gravity or if made a Tool like checking antifreeze how many balls float( Octane range) but does not exist @ least three years ago.
My yblock seems to run the best mixed with a can of royal purple octain and premium fuel. It's the happiest that way that's all. Tried other brands but it likes that mix.
@Mimilan I agree with your better definition of detonation and I miss spoke. The OP never really gave us a detailed reason for needing the octane boost other than when the time arose. He said it was a mild build so I assumed low compression. If he was experiencing pre ignition,this could be fixed with a timing or distributor recurve/vacuume change.
I would find out if it's detonation or pre ignition knock . Pre ignition is mostly caused by the wrong heat range of the plugs or something very small in the combustion chamber getting red hot and setting the fuel off pre maturely. Detonation is normally a timing issue. Too much advance which could be due to the advance springs in the distributor or just too much initial advance. If you can get 97 octane in your area I would use that. The "Octane Boosters" are priced so high it would make it a waste of money for every day driving and may not even work. Add a little diesel to the gas and see if that helps. I have run flathead Fords on straight heating oil. That's because it was free and I was broke. For those who don't know, Octane has nothing to do with power. It's strictly an anti knock thing. In essence it just slows the flame spread of the burn.
Volatility is the purpose of the 70/30 blend [Volatility being vapor point being lower] But remember it is only a slight increase in volatility, but enough to change the cold filter plugging point [CFPP] which is what is needed for winter driving Gasoline [and most short-chain hydrocarbons] have a higher auto ignition temp, so they have difficulty self igniting when injected. Apart from premature wear on a diesel pump/injectors you can run the engine on 100% gasoline if the fuel and engine is hot enough [but it won't start][we have tried this] Hence the need to blend^^^^ The 70/30 blend drops the BTU content by 5% so there is a power loss , when using lubricant oils there is approx 5% gain in power. Understand that these blends are just different weights [chain lengths] of hydrocarbons mixed together. Like using Toluene , it is very difficult to separate once blended [requiring distillation] People also need to be careful following advice here [due to Tax laws, Emissions , or Sanctioning body rules] Blending fuels can result a lifetime ban from the FIA [unless you know the loopholes] They take a view similar to using steroids.
The Jalopy Journal
