IMHO...junk. back your timing down a tad and when you go to the track get a few gallons of 110 and have at it.

Good info. Thanks, Brad!

It would appear that most additives don't even come close to meeting thier claims. I think I'll stick with my race fuel/pump gas mix plan but I'm gonna print that out for future reference.


Dave

This reaffirms that it's critical to achieve .035-.040" quench via head/gasket/deck height when selecting parts & I won't even consider an open chambered head anymore. With you being already built as said if there's an additive that works or blend in some av gas or race gas whichever ends up being the most cost effective for you.

i did research it, brad. did you notice something odd about those reported test results???

The talk about the octane rating in RON. the research number. when you use the R+M/2 method, you can cut those numbers all in half or so. so the claims of gain 2.8 points of octane shrink down to 1 point or so give or take.

my point about them being junk is that they advertise and make people believe they will raise your octane incredible amounts- hence 108 octane.... Thats bs. not even close to what the results are. and when you try and pull that snake oil type marketing bs on me, I call shenanigans.

they should clearly state that they will raise your octane a point- MAYBE and in the real world, you wont realize much from that as a simple adjustment to give you a slightly richer mixture or backing down the timing or adjusting the vacuum advance to come in later or under more vacuum could do the same.

I try to do the race gas/street gas mixture, but on long trips to the nationals, I have used the NOS stuff with positive results. I am on the cusp of being able to get away with 93 Octane, so it seems to work. Of course, I usually have a few gallons of the race/street mix, so I haven't soley relied on it. But is has come through in a pinch.

Eight miles from the airport,101 LL less than $3.75 a gallon,been running it 50/50 for 16yrs.They'll sell me all I want,just won't pump it in the tank..

How is the Moroso brand of octane boosters? Any tests on that one?

Moroso is just about the worst for eating things up like rubber lines.

Does boost octane though.

Do yourself a favour and get this stuff if you need an octane boost. http://www.kemcooil.com/products.php?cId=4

It is called octane supreme 130 and it works great because it has real lead in it. They are a chemical supply company that's mixes up an octane booster for "off road use" but I can tell you that it works really well. It is the same stuff they used to add to the hi-test in the 60's which is know as Ethyl. I would recommend that you use the best gas you can and then add 1-2 ounces/gallon. That should give you plenty of octane. I always have trouble with pinging until I bought a case of this stuff. When compared to mixing racing gas it might not be as cost effective but at least you can carry around a bottle and when you fill up at any gas station just mix some in. I think the other ocatane boosters that use chemical ingredients like MMT will also work but they don't seem as cost effective plus they dont have lead that the older engines like. If the booster is made from xylene or toluene, forget about it because those little bottles just won't be enough to make a difference in a big tank of gas.

Octane boosters, not lead or even MMT, work by averaging your octane.

IOW, if your gasoline has 92 octane and you put in 16 oz of booster with 115 (for example) octane you get a miniscule bump in octane.

You can do better, and cheaper, by running Ketone or other high octance hydrocarbons in your gas. Heck a gallon of Methanol or better yet ethanol will do more than a bottle of octane boost.

Lead, and to a lesser extent MMT, work differently by chemically altering the gasoline molecule to make it more resistant to lighting off, not by raisng the octane level though the effect is the same.

Octane is rated on a special test motor that can vary the compression ratio. The difference in MON and RON numbers is the temperature of the air charge coming in, essentially.

I get all my gas from the airport thats 15 miuntes away. 108LL for $3.49/gallon. Been getting it there for 12 years.

thanks for the web link to that tetra-ethyl lead supplier,
I will add that to my archive

Here is an archived article with info on another tetra-ethyl lead supplier that may (or may not) still offer it in bulk:

====

Lead additives
Chicago Tribune, Motormouth columnist Bob Weber

Q - Do you know of any sources for purchasing a lead additive for antique
autos? I picked up a 1963 Wildcat convertible in excellent condition with only
53,000 miles on it. I also have two friends in a car club who are interested
in a lead additive. They have'52 and '56 Cadillacs. We each drive about
600-1000 miles a year.

A - Gasoline used to contain a compound called tetraethyl lead, but due to
health hazards, it was removed. Although you cannot buy this stuff over the
counter, I found a distributor in Columbus, Ind. that sells it by the gallon
($22.95 per gallon) by mail. Although it isn't cheap, about 12 ounces treats
20 gallons of premium gas. "Max Lead 2000" is available from Vogel Products,
812-376-2775. They offer quantity discounts to car clubs.

There are other products available at most auto parts stores, but they are
lead substitutes and may contain a variety of other chemical compounds
including phosphates, sulfates, sodium and so on.

However, with as little driving as you and your friends do, and considering
that you probably baby your cars rather than race them, you probably need
nothing. Your engines will probably see no valve recession for many, many
years.
=======

on the subject of pinging and octane
here is another archived post
with two different people's
Rules of Thumb
about different engine settings
=====

Several days ago I posted Jim Bell of Kenne Bell Company's
'rules of thumb'
about octane, temperatures and pressure effects on engines.

Here are some quotes from a recent article on engine knock,
written by an engineer who just finished doing his Master's Thesis on Engine
Detonation at an Austrailan University.

I have converted the metric temperatures and pressures in the original article
to good old psi and degrees F. Words inside { } are my comments.

begin quotes
-----------------

"Causes Of Knock
As discussed, for a given engine the type of fuel is the most important factor
in promoting or preventing end-gas autoignition, also known as 'knock' or
pinging. The following guidelines show how various engine operating parameters
affect the fuel octane requirement of an engine. The higher the octane
requirement, the more likely an engine is to knock for a given fuel.

Effect On Octane Requirement
(ON = octane number)

Spark advance
1 ON per 1 degree Spark Advance
{ Jim Bell rule was 0.5 to 0.75 ON per 1 degree Spark Advance}

Intake air temperature
1 ON per 13 degrees F
{ Jim Bell rule was 1 ON per 20 degrees F}

Air/Fuel ratio
Chance of knocking Peaks at around 5% rich of stoichiometric {about 14 to 1}

Decrease of around 2 ON per A/F ratio around peak

{ so richening a Magnum engine from 14.7 at cruise, to 11.7 at WOT like the
factory PCM programing does, has an effect like switching gasoline from 87
octane to [14.7 - 11.7] x 2 + 87 = 93 octane. The extra rich mixture at WOT
is apparently an attempt by Dodge to reduce pinging. I wonder if the 'Reflash'
of the PCM computer by the Dodge dealer not only retards timing but also
richens the WOT mixture even more ? Jim Bell rule was also 2 ON per 1 A/F
change}

Intake Pressure
3-4 ON per 1.4 psi
{ so if a KN filter/inlet system actually lets more air pressure get to the
intake manifold this would INCREASE the tendency to ping. Jim Bell rule was
1.4 ON = 1.4 psi increase. Since 14.7 psi is atmospheric pressure and is also
equal to 30 inches of mercury 'barometric presssure' or 400 inches of water
pressure, then if you have a vacuum/boost gauge fitted to engine you can judge
how intake mods have affected your engine's need for higher octane gasoline. }

Compression Ratio
5 ON per 1.0 Compression Ratio increase/decrease

{ Jim Bell rule was 3 ON per 1 CR increase. The Mopar Performance PCM
computer advances the ignition timing by something between 12 and 9 degrees.
A better way to get both hp and better MPG would have been to raise the
5.2/5.9 V8 compression ratio from 8.9 to about 9.9 with a head gasket change.
The 4.7V8 has a compression ratio of 9.0, but with two sparkplugs per cylinder
and knock sensors the 5.7Hemi was designed for 9.6}

Exhaust back pressure
1 ON per 4 psi
{ so a low restriction exhaust system may increase pinging very slightly, and
a quick fix to reduce pinging might be to put a big dent in the exhaust pipe.
A stock 1995 5.9V8 has about 7 psi of backpressure at full throttle at 4000
rpm.}

Coolant temperature
1 ON per 18 degrees F
{ Jim Bell rule was 1 ON per 10 degrees. The 180 degree thermostat change
that is so highly touted lowers the coolant temperature by about 15 degrees
from the stock 195, so its effect is small - like putting 88 octane in instead
of 87 octane.}

Similar ON effect for cylinder head and engine block temperature.
{ so removing the rubber strip from the firewall cowl on a Ram truck may
slightly reduce the tendency to knock too}

For naturally aspirated engines, the two main design and tuning parameters
given in the table are the compression ratio and the spark advance. For an
engine at wide open throttle (maximum inlet manifold pressure) and normal
operating temperature; these two parameters, if increased, are then
proportionally the most likely to produce knocking combustion.

Detection Of Knock
There are several ways of detecting when knock is occurring in an engine. Only
some methods, however, are capable of measuring the knock intensity.

1. Sound of Knock
Knock is audible to the average human ear when more than about 10% of total
engine cycles knock. The human ear is the most obvious and readily available
device to detect knock. The ear is surprisingly sensitive and routinely used
in determining the octane requirement of an engine. The sound of knock is best
described as a sharp metallic "ping". This sound is caused by the high
pressure and frequency waves impacting against the cylinder walls, giving rise
to a ringing knock as though they had been struck by a light hammer. The
ringing noise is worsened by the way in which the energy of the pressure wave
is not completely absorbed when it first contacts the chamber wall. Instead,
the wave is only slightly diminished and then reflected back across the
chamber, continuing this process until all the energy is lost to the engine
structure as vibration or dissipated through the gas.

2. Sight and Pressure of Knock
A high-intensity flash is observed in the cylinder when knock occurs. This
facilitates the use of optical probes and ionisation detectors to measure at
least the presence of knock if not its intensity. Much of what we know about
combustion today has come from the analysis of photographs taken using
high-speed cameras as first successfully developed in 1941. More recently, as
the technology has become widely available, direct measurement of cylinder
pressures during combustion has been used to study knock. Direct pressure
measurement allows the study of the actual intensity of knock. The
piezoelectric pressure transducer has been the standard sensor for some time.
Typical pressure traces from a cylinder experiencing knocking and non-knocking
operation were shown earlier.

A major obstacle in developing feasible combustion pressure sensors has been
to overcome sensor performance degradation caused by high combustion
temperatures and strong electromagnetic interference (EMI) from sparkplug
wires. So far, due to inherent material limitations, conventional
piezoelectric type combustion pressure sensors cannot operate over 200°C
without water-cooling. In addition, signal conditioning electronics must
usually be located near the sensor head to combat the strong EMI and stray
capacitance loading effects of spark-plug leads."
-----------------
end quote

True, I was generalizing. Didn't want to get into a big chemical structure analysis. But generally speaking what I said holds up.

Kemco's Octane booster is $20.75 a quart.
32 oz in a quart and they rec 8oz octane boost per gallon. At that rate a $20.75 bottle will treat 4 frigin gallons! That raises 93 to 101 octane. (8 pts)
Same amount boost in 8 gallons will raise octane from 93 to 97. (4 pts)
One quart Kemco boost in 16 gallons will get you 95 octane. For $20.75?
There site says "will get 2-16 point increase in octane" If you use a full quart for every 2 gallons you'll get 16 pt octane improvemnt.

The local Speedway sells Race fuel. I think 110 octane. I just fill a 5 gallon can and add it to my tank.

My street 383 runs just fine on BP (Amoco fuel)premium. I put a few gallons 110 in once in a while anyway. Maybe waste of money but it's not $20.75 a quart.
Talk to your local speed shops I bet they know all the local places the sell Race fuel other than a track or airport.

It seems ALL octane boost is a waste of money.
I guess if you carry a quart on Kemco boost in your trunk it might be of use in an emergency. Like the only open gas station only has 87 octane.