High octane options

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71MACH-1

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71 MACH 1 351C (WITH A CAM)
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I have neen running 91 with octane booster

I drive a71 Mach 1 351 4v

I have some other options. What is recommended.

100 octane unleaded

110 or 114 (don't remember) leaded

And 116 leaded

Oh yeah, they are all $9/gallon!!! But that's ok if it's better for my Mach

 
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That would depend on your compression ratio and camshaft specs.
Don't know them. I bought it with an aftermarket performance cam.......

 
If you have all available, you should count yourself lucky. I am able to get 110 and I ran 3 gallons to a tank of 93 octane this last tank and was happy with the performance. Unless you have built a really hot engine, running over 100 octane is unnecessary. Also IIRC blending high octane leaded with a lower octane unleaded results in a larger increase in effective octane rating than the math alone would suggest. Something with the chemicals, but I can't say exactly, just a memory with the source long gone.

Run the lowest octane you can without pinging, anything more is flushing money away. Lead is good, without it, I run additives every few tanks.

 
You could experiment a little by letting your tank go almost empty and use about 3 gallons of whatever (start with the lower octane first) If you have issue, and you'll know right away, add 3 more gallons of the next + octane.

 
My 71 351-4v runs fine with pump 91. Just retard your timing until it stops pinging on accelleration.

Too much octane is not good either. With inappropriate timing for the octane you may burn exhaust valves because higher octane makes the fuel burn slower. So when you run higher octane, you need to also advance the timing.

New cars adjust the timing automatically depending on the octane.

The oil companies also changed the way they rate octane back in the mid 1970s.

So if your old 1971 requirement was 100 octane, this equates to a much lower rating with the new method, like maybe closer to 92. You might be able to find the exact equivelent on a internet search.

 
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I have neen running 91 with octane booster

I drive a71 Mach 1 351 4v

I have some other options. What is recommended.

100 octane unleaded

110 or 114 (don't remember) leaded

And 116 leaded

Oh yeah, they are all $9/gallon!!! But that's ok if it's better for my Mach

Reading from this new Cleveland book, it says a fuel like sunoco GT100 w/ octane rating of 105 Ron/95 Mon will support from 9.5:1-11.0:1,or Avation fuel. I believe the 71 4v was a healthy 10.7:1 with a 427.in/453.ex lift cam. but hey what do I know im just going by what i read.
 
Well you could do what I am doing, convert your carb to run E85. It runs cooler, makes more power, runs cleaner than gas, and doesnt fill your engine with carbon. In some places its less than $3 a gallon, so its far cheaper than race gas. It isnt corrosive to the fuel system parts, provided you have rubber hose made after 83, but it will clean all the varnish and crud left by gasoline. You also dont have to worry about water contamination when running ethanol, it absorbs it and lets you burn it. It does it the same way HEAT additive gets rid of water in your tank.

Alternatively, you can go to the hardware/paint store and get a can of toluene, that also increases octane but it is more corrosive to carbs and fuel system parts than ethanol, and is about $30 a gallon.

I have been running ethanol, both home made and E85, since 07 in my muscle cars, no problems with the fuel systems and the rubber hoses have lasted longer than they did running race or pump gas. Most of what you hear negative about ethanol is usually wrong, or is actually about methanol, which is very different. I would be willing to set up a carb for you if you want to try it, if its available in your area. I dont charge anything for the carb work, just need a rebuild kit and return postage. The VA wont let me have a business, but I will help friends with stuff. Its available in Tulsa and OKC, you can find out where here. http://e85prices.com/e85map.php

 
You need to be careful with Octand Boosters, they will taint you plug electrode a sort of chalky rust color, which will effect the spark plug performance.

I run 94 (either Chevron or 76 only though) and add Redline Fuel Injector Cleaner ever few tank fulls to keep the valves and everything inside clean. It runs solid always, no pinging, no issues.

Every now and again I'll run some 110 race gas through it and all my vehicles as well. I definetly notice the performance difference and the smell of race gas out the tail pipe is just an added bonus!

I think the brand of gas has more to do with it then the octane though. BP, Circle K, Am/Pm, Saefway, Costco, all suck and I wouldn't run it in my lawn mower. Stay with 76, Chevron, maybe even Shell on occasion and you should be fine whatever octane you run.

I would recommend leaving the octane boost alone though. Buy a 5 gal can of race gas and mix that in every now and again if you want some boost.

Liek I said, I recommend Redline SI-1, carb/injector/valve cleaner, you can run the whole thing in one tank, or just a shot here and there. It won't boost the octane, but does a really good job cleaning up all the deposit and crap that are left behind with the gas we have to all use now.

 
mmmm adding octane booster too low 87 octane gas is ok..But adding any of their boosters too 91 octane and above..can be harmfull at times.

Octane boosters can be broken into three types based on their active ingredients. Methyl cyclopentadienyl manganese tricarbonyl (MMT) and ferosene are used in limited amounts in off-the-shelf boosters. The majority of commercial boosters use MMT. Another type of booster uses alcohols or aromatics as the active ingredient. Many tuners use toluene as a home-style octane booster. Toluene, an aromatic circular hydrocarbon chain, is a regular component of pump gas and is available in various grades at chemical supply stores. Premium street gasoline carries roughly 3- to 5% toluene, which partially helps octane characteristics. Unocal's 100-octane race gas has almost 25% toluene.

The drawback to any of these additive ingredients is the diminishing effect they have on higher-octane fuels. Adding the same booster to 87-octane pump gas will yield a lot more octane gain than adding a bottle to 91-octane premium gas. Excessive concentrations of these additives also damage emissions-control hardware, such as spark plugs, injectors, oxygen sensors and catalytic converters. This is why most off-the-shelf boosters have an emissions-legal street formulation and an off-road formulation that exceeds the government-regulated concentration of MMT or ferosene.For the power-hungry, there really is no point in testing 87-octane gas and street-legal octane boosters. That's why we performed our tests with a base sample of 91-octane premium gasoline taken from a local SoCal station. By law this gasoline must have an octane rating of at least 91 octane. Octane boosters were obtained at local auto parts stores while 99%-pure gasoline-grade toluene was sourced from the laboratory of Rockett Brand Racing Fuel.

Read more: http://www.europeancarweb.com/tech/0503ec_octane_boosters_tested/index.html#ixzz1wx1EOXrW

 
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