At Arlington the Aircraft Spruce salesman told me to watch for a new
product that was reputed to be better than TCP (a mute point really as
nobody can find TCP for sale). So maybe this is it.
I can't comment on Decalin but I can pass on one piece of information
that many don't know. TCP themselves, and many knowledgeable sources,
all say that you should never use TCP in a higher than 1000 TBO engine.
NTSB reports site TCP (and MMO) as causes of accidents in high time
engines, where crap has been dissolved/dislodged, and has then managed
to stall an engine.
I mention this just because I believe you should check if Decalin
suffers from the same problems.

HTH

Tony
C-GICE

In article ,
Bob Fry wrote:

With the demise of 80/87 avgas, I bought a gallon of TCP and will
start adding that to the 100LL that I must now buy.

However, scouting around the internet I found something that claims to
be similar in function but safer: decalin. Here's a blurb from
Aircraft Spruce. My questions are, has anyone any experience with
both decalin and TCP, and how do they compare? And, in spite of the
last sentance below, can decalin be used beneficially in certified
aircraft engines?

"Scavenges Lead in aviation fuel after combustion to prevent lead oxide
buildup on valves but still allows the lead to perform the anti-knock
function prior to combustion.

"It is an excellent additive for auto conversions, where it reduces
buildup on oxygen sensors and plugs. If you have to use 100LL, then
this stuff is for you. Prevents valve seat erosion from valve seat
micro welding. It is equivalent to TCP.

"Does not contain volatile solvents so it is safe to ship and safe in
the cockpit. You can carry it with you for out-of-town airports.

"Easy to use graduated measuring and dispensing resevoir built into the
bottle. No messy syringes!

"Tested and stable down to 0 degrees F.

"Decalin TCP is not approved for use in the engines of certified
aircraft."




--

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE