[f-AA] Decalin runup fuel additive

[Nano Farabaugh]

Good afternoon,

I agree with the other fellow who mentioned missing more conversations on the f-aa website. 

I joined f-aa back when John was documenting his flight from California to Ohio with his son in the 90’s. I have enjoyed all the conversations and learned a lot from you all.  

I thought I’d add to the conversation.

What is your opinion of the fuel additive Decalin runup fuel additive? Do you use it? Any noticeable difference?

Recently a mechanic suggested that I use it. He also suggested a  slightly higher RPM than I had been using.  He reported one cylinder's compression numbers were down a bit.

The engine is a 0-200 in a 1973 Bellanca Champ with about 900 hours on it. I fly about 4 hours/month in northern Indiana. 

I have limited understanding of engines, but have been a pilot since 1967 and appreciate learning more. 

NF Farabaugh

--
fearless Aeronca Aviators mailing list
To unsubscribe from this group and stop receiving emails from it, send an email to aeronca+u...@westmont.edu.

[Mark Peterson]

Most additives aren't going to fix any problem.  This is just TCP in a different package.  You can't fix anything with fuel/air ratios with it.   I assume you have a starter and electrical.  One cylinder down on one compression check isn't anything until the next compression check.  You can have rings that line up funny.  You can run the engines up to redline just fine.  Fly it, monitor it.  If you want to get a good look, do a oil analysis.  But I would take this with a grain of salt.  If you can run non-ethanol MoGas with the STC, try that way before TCP.  That will do more to get rid of lead than TCP.  A mechanic who suggests a fuel additive is met with a raised eyebrow by many. 

IMHO,

Mark

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From: aer...@westmont.edu <aer...@westmont.edu> on behalf of Nano Farabaugh <nfara...@gmail.com>
Sent: Thursday, April 3, 2025 9:42 AM
To: aer...@westmont.edu <aer...@westmont.edu>
Subject: [f-AA] Decalin runup fuel additive

 

[Don Harvie]

I’ve been in using Decalin in the RV with a Lycoming O-320 for just over a year now. More than half my flying is in formation and therefore at full rich and any power setting from idle to full power. I only run 100LL in the RV

I seemed to spend ages picking lead out of the plugs the first few condition inspections. This year my LAME (A&P/IA) did the plugs and he put them straight back in - a very small amount of lead he said. So I take that as a promising sign that the Decalin might be helping

In the Auster I run low octane ethanol free mogas unless I’m going cross country in which case it gets 100LL. I run it at the allowed max continuous rpm, (2300 for the Blackburn Cirrus Minor II).  Dad always did the same thing in the Chief, (C-85 with O-200 Crank, rods & pistons STC). In future when using 100LL I’ll likely chuck in the Decalin into them too. We can still get ethanol free mogas in 91 and 98 octane. Our 98 has additives that don’t like Perspex/ Acrylic and so I avoid it given the proximity of the windscreen to the tank on the Auster and Chief.

Don H

On 4 Apr 2025, at 3:42 am, Nano Farabaugh <nfara...@gmail.com> wrote:



[Don Harvie]

Mark,

Decalin Runup is an uncertified version of TCP. It has the same active ingredient that converts the conductive lead oxides into more friable non-conductive lead phosphates as TCP. It also not subject to hazmat shipping rules as the carrier liquid is different. Theoretically, because it’s uncertified it can’t be used in certified aircraft - but if it reduces the chance of lead fouled plugs I figure that’s a good thing.

Don H

On 4 Apr 2025, at 3:59 am, Mark Peterson <mrpet...@msn.com> wrote:



[Richard Murray]

I discovered TCP when I acquired a 150 Franklin in a Stinson. The previous owner encouraged its use and after 100 hours on the plugs running 100LL they were lead free.

Then I started using it with an A-65 in my Chief and enjoyed the same experience.

As I understand it the TCP or Decalin scavenges the lead additive from the fuel.

It does add about $0.70 per gallon to your cost of operation.

Richard in OH who doesn't believe in additives but I did try MMO once

['Botijo G' via aeronca]

Long live MMO!!!!

Sent from an NDB

On Apr 3, 2025, at 8:21 PM, Richard Murray <murra...@gmail.com> wrote:



[Dan Vandermeer]

TCP (brand name “Alcor”  is (in my experience) an effective fuel additive. But read the label! It is highly toxic. It is absorbed thru the skin and gives off fumes that are toxic if inhaled. It is particularly dangerous to dogs. They are known to have died from chewing shirts or pants or rags that were contaminated. 

Sorry to sound negative but I’d rather take a bath in MEK than be careless with this stuff. 

Sent from my iPhone

On Apr 4, 2025, at 09:04, 'Botijo G' via aeronca <aer...@westmont.edu> wrote:

Long live MMO!!!!

[John Rodkey]

That's a really good reminder. Thanks.

--

John (poobah) Rodkey - N9361E 11AC at Goleta

[Don Harvie]

Dan, Do you know whether that is the active ingredient TCP or the carrier liquid in Alcor that is dangerous? I had the container of Decalin develop a hole in the RV and it affected the paint. It caused the paint to soften and crinkle up. I’ve always understood that Decalin is a bit safer mostly because it doesn’t attract hazmat shipping restrictions. I never realised it was so toxic.

Don H

On 6 Apr 2025, at 12:32 am, Dan Vandermeer <danv...@gmail.com> wrote:

TCP (brand name “Alcor”  is (in my experience) an effective fuel additive. But read the label! It is highly toxic. It is absorbed thru the skin and gives off fumes that are toxic if inhaled. It is particularly dangerous to dogs. They are known to have died from chewing shirts or pants or rags that were contaminated. 

[Richard Murray]

I truly love this maillist.

Just real people that post factual content.

Thanks Dan

[dave savage]

Richard, People who soak in MEK do not remain friendly too long.

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From: aer...@westmont.edu <aer...@westmont.edu> on behalf of Richard Murray <murra...@gmail.com>
Sent: Saturday, April 5, 2025 2:38 PM
To: aer...@westmont.edu <aer...@westmont.edu>
Subject: Re: [f-AA] Decalin runup fuel additive

 

['Botijo G' via aeronca]

And they don’t smell good! It you do it with MMO at least you smell good!

Sent from an NDB

On Apr 5, 2025, at 6:50 PM, dave savage <sava...@msn.com> wrote:



[David Polley]

Good afternoon.

I have a aeronca 11AC with a C85-12F Engine on it and am looking for a 337 of some sort so i can get this approved. The SL 17 as far as i know was approved and am looking for some more information for this approval. 

Thank  you all for you time

David E Polley

--

David E Polley

Quality Aircraft Maintenance

253 377 7645 cell

801 761 5046 fax

[Richard Murray]

Bill Pancake has an STC that covers exactly what you have and permits the retention of the small tail.

Richard in OH who likes the lines of the 11AC best 

[Duane Fey]

I did the STC on my ‘46 Chief. It covers everything and is quite simple. I recommend you contact Bill. 

Duane

‘46 Chief, N85981

On Apr 9, 2025, at 16:50, Richard Murray <murra...@gmail.com> wrote: