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