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