Fuel Octane

[fastd]

I would be interested to learn how everyone handles their need for higher octane fuels. Do you use pump gas (what is the highest octane pump gas out there?); additives? race fuel?

What is the best octane balance in your engine? and what engine and compression are you running? Regards.

[Ron61]

My car requires leaded high octane as I have never had the heads worked over and new valve guides and such put in. We can only get 87, 89, and 91 octane up here an I doubt if you tested it if it would even be that high. And now that they are changing to Winter gas it is even worse. Fortunately I don't drive my car much and I just buy a barrel of 110 octane leaded racing gas and it lasts me a couple of years.

Ron

[mdross1]

When building my motor back in the early 90's, 91 octane pump gas was the option,so settled on 9.5:1 cr and run as much timing as the fuel would let me.It is the only option we have without needing racing fuel.

[dcdoug]

I run 93 octane pump gas on my 11:1 FE. If I am in a state that only has 91, I carry octane booster to make up the difference.

[SunDude]

My Ford Racing crate motor specifies 92 octane, but the only gas available in my area that meets this minimum is Sunoco's Ultra 94 so I'm paying for a bit more than I need. Better than going under I figure; besides Sunoco uses top tier detergents in their fuels up here which is an added benefit.

[springin]

Good ol octane booster from walmart works just fine. My car won't idle properly and has a tough time accelerating in any gear without it. About 6 ounces per ten gallons does the trick with 91 octane. 351C with 10 to 1.

[pazcarguy]

I used to run a 66 mustang strip car on the street with a worked over 289 (11.5~1 CR) I found a place in Utah that sold concrete sealers and octane booster(strange product mix). Their product used real tetraethyl lead and you could buy a case (12 bottles) for about 125$. I forget the name of the company but each bottle could treat a tankful with an increase of 8 full octane points, not the garbage you can but elewhere that only increase octane a half to a full point. Should be able to find it thru internet searches though. Worked great. Brian

[SP01715]

I blend about 3 gallons F&L 111 to 10 gallons 91 pump gas. I played around with ratios, and this works well for me. I used straight 111 and the car ran like crap on the top end. I talked with Roush and they said to decrease the octane, and it ran fine. I was getting a little run on with straight 91, which went away with the blend.

[fastd]

SPO1715,
So that ratio of 3 @ 111 and 10 @ 91 yields a 95.6 octane. That works best for you? What compression is your engine?
When you used straight 111, you said it ran like crap at the top end; what is your top end defined as? At RPMs above a certain level? Or MPH above a certain level?

How did it run at the low end?

[HI Cobra]

Here in Hawaii we have the 92 octane with 10% ethanol. I have a 351w
with the aluminum heads - 405 hp. Ran ok but I started adding 1 gallon/10
of 110LL avgas and what a difference that made in the higher gears. I have
the .64 5th and the minimum I could drive it in 5th on the flat and level was
65. With this blend 55 is no problem and I can leave it in 5th going up H3 at 65
where before 4th was a necessity. Mileage went up by about 3 mpg too. With a 3.27
rear this blend made the 5th a lot more useable for me for cruising.

[RET_COP]

Lucas Octane Booster is sold at autozone. I found this to be a quality booster and will treat 25 gals. I read from many sources that it will raise 91 Octane to about 93 at that ratio but you can add the bottle to less Gas and up this number another point or so. Its not that expensive for the insurance it provides. I have 10.5:1 static Compression and my motor runs great at 34* total timing.
Lou

[lal Naja]

Sometime ago, I did some research on boosting octane and found the information below. The link will take you to a great site that is most informative and a must read/reference guide.

Arthur

http://www.gnttype.org/techarea/misc/octanebooster.html

Toulene
R+M/2...114
Cost...$2.50/gal
Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores.

[HI Cobra]

Any suggestions as to where someone can buy toulene? I haven't been able
to locate it here in Hawaii. Haven't looked for it in Texas yet.

[pazcarguy]

Originally Posted by fastd

I would be interested to learn how everyone handles their need for higher octane fuels. Do you use pump gas (what is the highest octane pump gas out there?); additives? race fuel?

What is the best octane balance in your engine? and what engine and compression are you running? Regards.

Here is the link for the product I spoke of earlier. A case lasted me two years of weekend driving.

http://www.kemcooil.com/products.php?cId=4

[SP01715]

Originally Posted by SP01715

I blend about 3 gallons F&L 111 to 10 gallons 91 pump gas. I played around with ratios, and this works well for me. I used straight 111 and the car ran like crap on the top end. I talked with Roush and they said to decrease the octane, and it ran fine. I was getting a little run on with straight 91, which went away with the blend.

10-1, and yes it works well. With straight 111 it felt like the limiter kicking in over 5000 rpm. At first I was thinking there was another problem. I talked to Roush and they asked what octane I was running. I told them 111 and they said to just use premium pump gas. Premium gas here in CA is only 91 (some states are 93) so I wanted to bump the octane a bit. The easiest race gas for me to buy here is 111 (I can get it straight from the pump). I started playing with ratios, and the above seems to work best. No run on on shut down and runs perfect on the top end.

[Zoom This]

My 418W usues 91 pump octane. Compression ratio is 10.83:1 with Victor Jr. aluminum heads and 32 degress total timing in at 2400 rpm.