Octane booster ??'s

[70burntorangeT/A]

I have a 1978 440 that i ahve in my challenger, it is out of a motor home so it has the better crank (either cast of forged, i cant remember which one is the better one?) and stronger pistons and rods. It is stock other then a set of headers, would using octane booster help the performance of it any at all since it was built in 78, after they lowered the octane levels in gas? Also i have a 1966 ford truck that has the stock motor, that probably would benifit a little from better gas, its a 240 6 cylinder. when going up steep hills using 87 octane you can really hear the lifters rattling, i was told it was because it was made to run on much better gas, so i run 91 now, which is the best i can get around here and it helped out but it still does it a little, the bottle of octane booster i bought says that it treats 15 gallons, and boosts it UP TO 15 points. So is that bottle going to boost 15 gallons 15 points or is it only going to boost it a little and it CAN boost it 15 points if i just dont mix it with as much gas?? My main concearn is that i might possibly damage my engine buy boosting the octane too much, i dont know if that can even happen, but i just dont know much about octane booster. Any help is appriciated.

[wagesofsin]

octane boosters are ok.... just ok. better gas is better. check the timing, check everything. o/b can be a band-aid, and mask other serious issues.
its ok to use once a month, (or less) in a full tank of gas.
make sure you put it in before you fill up(i.e. like, almost outta gas and at the pump)
do you buy gas at the busiest station around?
more busy, means better , fresher fuel.
be consistant, and take notes as you make changes, thus narrowing down variables, and eliminating suspects.

[Chryco Psycho]

well with a low compression 440 adding octane booster is useless , the higher the octane the harder it becomes to ignite the fuel this helps with high compression engines as the fuel will detonate from the heat created from the compression , with low comp engines you do not need this added resistance to burning .
 Cast cranks were typically used after 72 forged are the stronger cranks

[70burntorangeT/A]

well with a low compression 440 adding octane booster is useless , the higher the octane the harder it becomes to ignite the fuel this helps with high compression engines as the fuel will detonate from the heat created from the compression , with low comp engines you do not need this added resistance to burning .
 Cast cranks were typically used after 72 forged are the stronger cranks

My dad is really good friends with the local engine builder and he told us that the motor home engines had the stronger forged crank to handle the extra stress of pulling a 14000 pould motor home around.   I believe the compression ratio was also a little higher then a 440 that would have gone into a car. I think its either 8.7 or 9.0:1

Any idea if it would help out on the truck?? the compression ratio for the truck is 9.3:1

[6packCuda]

The noise you're hearing going up a hill in your pickup is not the lifters rattling. You're actually hearing the cylinder walls rattling from detonation. This can cause serious damage to your pistons if you let it continue. I would try the octane booster in a couple of tanks and see if it helps. You're not going to hurt anything.

[Devil]

Octane Booster, the stuff you buy off the shelf is just snake oil.  It raises it 3 points... as in 91.03  not 91 to 94. 

If it is a 78 440, it is a forged crank, and they didn't have anything special with the cranks.  They were low compression smog motors that were built to make torque, not horse power. There wasn't anything "extra strong" about them.

[1970-cuda340]

I've used this product and it works great. I even use it to make fuel for the race car. Great thing is it has lead for the older non-hardened valve seats. Definatly not snake oil.

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

[moparniac]

I've used this product and it works great. I even use it to make fuel for the race car. Great thing is it has lead for the older non-hardened valve seats. Definatly not snake oil.

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

that is the good stuff... that octane booster is junk. read it closely how many bottle you need to raise it 1 full point 

[rallye73]

Torco makes octane booster for leaded and non-leaded applications. I've used in in the past with good results. It is sold in quart bottles with mixing ratios on the label.

[Changin Gears]

If the 440's not rattling now I wouldn't worry about it.  For the 6 cyl Ford I would dial back the timing 2-4 degrees until it stopped.

Too much octane will not damage the engine, but will make it difficult to light.

[jh23job]

I work with a couple of people who have been formulating gas additive/octane boosters for about 20 years.  According to them, none of the additives will truly make a 91 octane gas function properly in an engine with a compression ratio over 10:1.  One option that I have used in my T/A for years (ever since the late 70's when we moved to unleaded) is check out the local airport.  Once you learn the ropes you learn that most small airports have self-serve gas pumps.  You can easily buy 100 octane leaded gas from the pumps in a can and use it in your high compression engines (of course for OFF-ROAD purposes only).  I recommend adding 2 & 1/2 gallons of 100LL aviation fuel mixed with enough 91 octane unleaded to yield 15-16 gallons of about mid 90's octane.  This mixture eliminates all pinging in my 340.  After 4 fills (10 gallons of Av gas).  I can go another 4 fills using just the residual lead in the system before it all washes through.  Again, this is ONLY for off-road use since the Av gas does not include any road taxes and it does contain lead which is not supposed to be used in passenger car for road use.

[shadango]

Hey jh23job...

You mention lead....

I have been using a lead substitute additive the last coupe of tankfulls....waste of money too or useful?

[Matt]

they have really cracked down on the use of av fuel in my neck of the woods for the last 10 or more years..we use to drive right up to the pumps at the local airpot 25 years ago in guelph ontario >>> and filler up<<<...but at that time none of us really needed the av fuel...we just thought we did..none of us had anything that "was hopped up up over 160"  ...
   I have a 1970 340 10.5 to one and .030 over..seems to run fine on 91 and I do not ad anything..no pinging at all...must be canadian fuel  huh? ........Matt ...

[LAA66]

 Don't get caught pumping Av gas straigt into your tank or it may cost some big$$ fines. Just fill a couple 5 gallon cans and explain you have an experimental aircraft at home if anyone asks.

 

[Matt]

well if they can catch you !!!