i was just wondering what your thoughts were on octane booster. i know its a lot cheaper than race gas, but does it hurt the engine if your running 13:1 compression and a pretty big cam?

 

Unless you're putting tetraethyl lead or some kind of "real" octane booster in your fuel, it's not going to do much. Those little bottles you get at the gas station might raise your octane rating by maybe 0.1 octane number.

 

IMO, buying that stuff ranks up there with spending $6 on a Bosch Plat. +4 spark plug.

 

it's great stuff if you don't mind spending money for no preformance gain or advantage

 

Silly ede, that's why Chrome was invented.

 

hey I spend anywhere from 5.99 to to 7.99 per plug

but guess if I wanted to I could buy the good plugs for 20-35 a plug

 

I have had some experince this year with octane booster, I run 10.5 to 1 in my big block And it will knock with 87..but not on 91 or 92, but with the addition of a generic octane booster (stp)and 87 octane it keeps it out of knock. I use the whole bottle for one tank and it works on mine. With 13 to 1 I don`t know if you`d ever hear it knock till it was too late, I don`t think I`d try it
I have noticed some side effects

1. now and then but not every time it will huff thru the carb when I shut it off

2. The fuel has a different odor if your working with it

3. Yesterday it began to pop when it was cold and then went away after it was warmed. After work it started it and it was doing the poppin again, after pulling the plugs (4.00 each) a/c rapid fires..they appeared to be fouled by oil or fuel...sandblasted them and no more popping. They`ve been in the engine over two years and have never done that before...this after running three complete boosted tanks of 87.

 

Your gonna need a few bottles for every tank to get it to work. Not worth it.

Just drop the CR down to 10:1 or so and be happier

 

I didn't say that anything was wrong with the GOOD plugs that cost a lot, just the Bosch Plat +4's that cost a lot.

Viper, Why are you running 13:1 compression and thinking about taking it on the street? It would take an unreasonable amount of booster to boost the octane rating enough so you could use pump gas (and booster). I agree with AA on this, drop the compression rather than looking for excuses around it. If it's a stret car, in the end, you'll be happier.

 

who said anything about good plugs

those are the base style plugs for my car


the "good" ones I guess like the iridiums are about 20-30 a plug
or the pure copper ones
about 35 a plug or more






as far as compression I have read in a mag somewhere about a project where they made 12.3 compression 502 running 87 octane
now if I believe them which I can see it happening if setup right that is kinda nice

 

don't kid yourself, the money you spend on a real octane booster (something with MMT or similar lead/manganese substitute that's concentrated enough to actually function as a valid anti-knock) or toluene will put your costs at about the same as running $4-$5/gallon race gas if not over. A 13:1 car isn't going to be any kind of daily driver and if you think it is, you need to realize it's 2004 not 1964 lol. Just get some race gas and store it with some fuel stabilizer and fill it up only as needed. The car game never was cheap and if you're running a motor as mean as a race cam'd 13:1 comp engine, you didn't hold back on anything when building it and streetabile wasn't an issue. I don't favor dropping to compression and killing all that power though. Besides a cam matched for a 13:1 comp motor won't work very well in a 10:1 comp motor.

rx7speed, I've heard of pump gas 12.5:1 compression motors, but they never ran 87, they were running 92-93 premium grade gas with a mild timing curve and long rods. it was also aluminum headed and they had to mirror polish everything in the cylinder from the combustion chamber to the piston tops and valves to prevent any hot spots from forming to create a source for detonation. it's just not worth it to try and run pump gas on a motor that clearly needs race gas to make full potential, and it can be very risky. I say 12.2:1 comp max if you're looking for a street motor with aluminum heads, and 11:1 max with iron heads. Just get race gas, run the aggressive timing, kick *** and take names and money to pay for your car expenses. it's what all the big boys do

 

go to the local airport and get some 110LL, back a few years ago when I was taking flying lessons it was 2.13 a gallon (1999/2000 time frame, I don't know how much it is now), it has lead in it so be careful with O2 sensors and cat's, also if you want to go through changing all the seals to neoprine you can add methanol, (anyone got a still, I hear moonshine works best ) it is a real good octane booster.

 

It's not going to work. Go to any .PROFFESIONAL race event and see
if any of the teams are using little cans of octane booster.

A 13:1 compression motor will need 110octane gas.

 

If you can afford a high compression motor then forget about that little can that cost $1.50.

 

the object of the build wasn't to make MAX power
but rather to make I think it was 500-600 lbs/ft of torque while still being very efficient

don't know where the mag is but they used all off the shelf parts
ran a A/F ratio I think of around 13.x:1
some sort of figure 8 style heads think fuellen or something like that
weird thing is the heads valves where smaller then what you would find on a SBC head but guess they are really efficient heads and don't need the huge ports

but if you want will find more info later

or you can search for my name and find it there

my name and evans coolant should help out

 

thanks, i was just wondering why nobody uses it. i'm not planning on building an engine like that any time soon either, i'm going to drop in a mild 350 for now and work on my 327 and make the car into a race only car.

 

500-600 ft. lbs on 87 octane is what the GM 502 H.O. crate motor makes w/8.75:1 compression. seems like a lot of crutches to run avoid running a $4/gallon race gas and make more power. Its just an experiment I wouldn't call it efficient at all though, a 12.5:1 comp 502 with matched parts running race gas should be over 700 HP and 700ft. lbs at minimum. All I'm saying is it's pointless to build a race motor then detune it so you can run pump gas in it. why bother building the race motor in the first place, cut the build costs in half with a street motor and make less power. I want to try Evans coolant in my car but it's $75 for a full cooling system fill and it can never have any moisture in it. I guess you'd have to completely flush and drain the cooling system then run the engine for a while to boil out any water remaining in the engine before you fill up with it. Cant see any other sure way to remove water.