The Stovebolt Site Forums The Shop Area Engine Shop octane booster

I just took my 427 for a ride the best pump gas I could get still nocks on hard pulls. Can anyone recommend an octane booster that won't cause other problems? I had been told they leave deposits that damage valve stems.

Kedso, this stuff is real tetraethyl lead just like the stuff in gas when your 427 was new.I use it in my vintage cycles it really works.I have no experience with the off the shelf boosters.A guy had a bunch of it last year, may be too expensive for use in a thirsty V-8 though.If you are interested,email me, I can give you his phone number Kedso, this stuff is real tetraethyl lead just like the stuff in gas when your 427 was new.I use it in my vintage cycles it really works.I have no experience with the off the shelf boosters.A guy had a bunch of it last year, may be too expensive for use in a thirsty V-8 though.If you are interested,email me, I can give you his phone number. Lead

Now we know what Tony has been drinking!
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What year and compression is your 427?

Cars and Parts has an ad under Chevy parts - "Now Available: a fuel additive which contains...lead...103 octane'.

Of course, I don't condone leaded gas, and my rip roaring 216 doesn't require it. :p

Real lead is very dangerous a drop it enough to kill you

Try taking some timming out
Less lead less knock
You may find 3-6 degrees solves this

I have a 1990 Mk VII Linc with a positive displacement supercharger. I have used 104+ in it when I run the 8 lb pulley, which helped, but still wasn't perfect. I ran it with a full bottle in 20 gallon tank for that way for about 3000 miles. Plugs turned orange, other than that, no problems. You might try it and see how it works. I also used a tank of race gas once to see if that would help. I don't think my injectors put enough fuel down. You can also try retarding the timing a bit to get the burn to go sooner to avoid knock, however, that will raise engine temp, and about 3 degrees is worth 30 hp. I also had a crane spark brain that would backup the spark electronically and that helped as well, but you lost a lot of go when you had the ping completely eliminated. Now I just run about a 4 lb pully and get no knock and for the most part have no problems. Another old hot rodder trick is to run a 160 degree thermostat to make the engine a bit cooler to avoid pre-ignition.

darn it guys ,put in your gas tank , don't drink it.Ever siphon gas back when and get a mouthful of leaded premium?Ever clean parts and stick you bare hands in the gas?Of course not, we were all sooo careful in the good old days.The ad in Cars and Parts is the same guy I bought it from.

The engine is a 1970 with 11;1 compression. I was only thinking about the stuff on the parts store shelves. Like Proffit said real lead is very dangerous. The reason we got away with careless handleing in the old days is that the lead was chemically bonded to the gas molecules.

I use the octane boost from my local parts store...don't know the name of the brand. It works for me. I use it in the dirtbikes and you can really notice a difference. I run high test anyway but the boost makes em real snappy.

Pretty pricey to be burning in a big block, but hey; "You can't put a price on a good time"!

Check this page out:

http://www.honda-tech.com/zerothread?id=201794

They discuss using pure tolulene from the paint store to increase octane.

Most over-the-counter octane boosters don't work very well. When they say they increase octane by five points, they mean .5. Thus 93 octane becomes 93.5 octane.

A rough equation to equate compression ratio with octane needed is to roll the decimal place over one. For example, a 11.0:1 engine needs roughly a 110 octane fuel. 9.5:1 engine needs about 95 octane fuel.

Retarding ignition timing by 2 degree increments, richening the fuel mix, and using cooler sparkplugs can help prevent pinging/detonation to some extent.

Good luck

chip

Guys be careful too much tolulene you wiil have NO RINGS LEFT!!

It's also not too good for fuel cell foam and some
rubber hoses

Did you know that 'No lead' is globalization plot???

We get less milage and the wealth of the driving public is redistubuted to Multi-national Banks!!

Nope,,,,uh-uh,,,,not a conspiracy!!!
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Keep buying gasoline they need new yachts!

One warning - some off the shelf boosters contain claims like "10 point octane boost!" One might assume that 92 pump gas + 10 point octane boost = 103 octane.

WRONG!

One point = 0.1 octane. 92 pump has + 10 point octane boost = 93 octane.

-Boyo

Gentlemen,
My experiance has told me to run either CAM2 race fuel or VP Racing fuel. Both have worked very well in my dirt bikes and several racecars that I have built. The racecars had 11.5:1 comp and no nice new electronics to help out just old electronic ignitions and carbs. I hope that you can find this stuff. Recently I've only been able to find it at the race tracks. What about aviation fuel, that has very high octane. But I don't know if you can use it in a on road car, legally or safely.

Around here, the C-12, C-16, VP, CAM, etc are all available at the speed shops. But the price ranges from 3 to 7 dollars a gallon. The local airport will sell the AV-GAS if you walk up with a large gas can for about 2.50 a gallon. It is 116 octane leaded gas, so can't use with a converter. It also has some de-icers and stuff you don't need, but the local guys run it in their pre-emissions hot rods.

But for a street driven car, I always say that its better to lower the comp ratio during the rebuild. Have hardened seats installed and dish the TRW flattops for about 9.7:1, and you can run pump gas and have good power. And you don't have to worry about the little detonation monster banging away at your pistons.

chip

If you mix unleaded and leaded gas together you get a high octane number.....much higher than the average of the two.

Something to do with adding lead to highly refined
unleaded....

The 39 BMW racecar has lottsa compression....I run it on unleaded....no det....45 degrees of timing
gotta start the fire early in a hemi.

The engine was designed to run on 80 oct fuel

I'm with chiphead on this one. Why fight it? Build the engine for the fuel available and avoid the hassles. If the right cam is selected during rebuild, the effective compression ratio at RPM will be increased without damage to the engine. The cam manufacturers can help pick the right one for your application.

Of course, if you have a good engine already running like the 427 here, this isn't much help. Retarding the timing a couple of degrees and richening the mixture are about the best you can do (in addition to octane boosters), unless you want to spend a weekend changing to thicker head gaskets-which won't drop the ratio much.

One other thing: Get a vacuum advance can that pulls off timing sooner. GM makes one for the HEI that will start dropping advance at about 15 inches of vacuum.

Good luck,
Banjo