Got this from
another newsgroup. Could be the answer to Rotary plug fouling when using
100LL exclusively. Use care though, new stuff often has unexpected outcomes.
You know?
-al
wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru
2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install,
Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
As promised, I’m
reporting back on fuel additives.
I have spent a
lot of time over the last six months researching most of the additives used
as ingredients in fuel additives and quite a bit of time doing engine
testing. I used an air cooled, low compression, fixed timing magneto
ignition engine for tests. I removed the cylinder head after each test
and took digital pictures of the head, piston and plug. I only used
100LL as fuel.
Here are my
results; on some things I can’t get too specific because they have become
proprietary.
Starting at
the simplest additives, here are the ingredients of Marvel Mystery
Oil. I shall call it MMO as an
abbreviation.
Hydrotreated
naphthenic oil
Paraffin
oil
Oil of
Wintergreen (methyl salicylate)
Red
dye
This stuff
was invented, as the bottle claims, in 1923. Back then engines were
rather primitive and so it this mixture. The active ingredient is the
naphthenic oil; the rest is just for dilution or to confuse the
opposition. Naphthenic oil was used originally as a low cost “once
through” oil in IC engines or compressors with either no recirculating oil
system or a poorly operating one. The oil has marginal oxidation
resistance so it is rapidly degraded and can only be used in once through
systems.
In my engine
testing it left the combustion chamber looking sooty. Subaru engines
operate hotter so it probably burns off this soot, so this is probably less
of an issue. The best benefit that could be obtained is valve guide
lubrication and upper cylinder lubrication. At 4 ounces per ten
gallons it is not very economical.
Next in line
is a whole slew of solvent based brews used as clean up additives.
These use toluene, xylene, trimethyl benzene diluted with paraffin oil and
solvent naphtha. Simple amines are used sometimes, as in
Redex.
In engine
testing these tended to clean up the inlet valve and fuel injectors, but it
was a slow process.
TCP
additives evolved from this type of formulation. Tricresyl phosphate
was diluted with toluene to make Alcor TCP. This is used to alleviate
lead contamination of spark plugs and exhaust valve seat recession due to
the presence of lead in leaded fuels.
Decalin TCP does
not use toluene, it uses ethylene glycol as a diluent which is far less
volatile and so it is safer to use both from a toxicological standpoint and
carrying it in the cockpit.
In my engine
testing, a high dosage of Decalin TCP tended to leave yellowish deposits of
lead phosphate in the combustion chamber and on the exhaust valve. At
the recommended level of ˝ ounce per 20 gallons for Subaru’s the deposits
were negligible.
The next
generation of fuel additives took a quantum leap in performance with the
addition of polyetheramines. This was patented by Chevron in the mid
1980’s, but the patent expired three years ago. Since that time there
has been an explosion of products containing this
additive.
I had a lot
of trouble getting hold of the raw material polyetheramine since the
manufacturers are picky about who they sell it to; but finally, in the
interest of bringing you the very latest stuff I persevered (walking ten
miles into the wind through three feet of snow uphill both ways, bring on
the violins) and then I put it to the test.
I first
“dirtied up” the engine by using a high dosage of MMO.
Then I added a
bit of polyetheramine concentrate to the fuel tank and ran the experiment
again. The effect was remarkable. The combustion chamber and
piston were very much cleaner. I could not believe it and ran the
test again.
I then ran a
whole series of tests, comparing and mixing with Decalin TCP, MMO and other
fuel additive brews that I bought at the auto
store.
I used a
great many head gaskets in this testing and the local supplier must be
wondering what I’m up to.
The bottom
line is that I am reformulating Decalin TCP to include polyetheramine.
This will make it a super product and I will call it Decalin TCP Plus.
The price remains the same.
Also, I will
bring out a separate product called Decalin DeeCoke for combustion chamber,
fuel injector, inlet valve and inlet manifold cleanup. This stuff is
so good that you only have to use it once every 50 hours by dosing at 5
ounces per 10 gallons. It will be in a 16 ounce bottle, priced at
$11.95.
You can use it
at a maintenance level of ˝ ounce per 10 gallons at fill up and then you
would not need the 50 hour dose. High dosage has no detrimental
effect on the engine that I could see, and other manufacturers report the
same thing. The ingredient is on the EPA list of approved fuel
additives. It can be used in cars also.
It will be a
couple of weeks or so before I can get bulk supplies delivered to make these
new products, but if you are interested in this product please let me
know.
Chris
Lowery