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David Roth
Trusted Member

I am new to Stinson ownership & would like to know what fuel is best for the Franklin 165 engine.  No ethanol mogas or 1ooll with TCP added.  Does it make a difference?

I can get the no ethanol locally but hauling & pouring the 5 gal. cans is a real pain.  Especially the pouring part---up on a ladder with a 30 lb. can.

Thanks all!

David 

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Posted : 12/11/2019 7:21 pm
Eddie Stewart
Eminent Member

Dave, The best fuel for your Franklin is the non-ethanol mogas. I agree that hauling and pouring the 5 gallon cans is a pain. I will be looking at a 100 gallon fuel tote that has an electric pump on it to transer mogas to my plane. My airport has no commercial fuel available. If you own a pickup truck you could put a removable tank in the back of it or install the tank on a small trailer. I think this setup would pay for itself in a short amount of time given the difference in the price of mogas and 100LL plus TCP.  Lots of places like Tractor Supply or most light truck upfitters will have transfer tanks available at a decent price.

Eddie StewartElmore City, OklahomaN906C 108-3 Continental O-470

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Posted : 12/11/2019 7:56 pm
Eddie Stewart
Eminent Member

Dave, I need to add that a lot of the cost savings using mogas will be from maintenance issues such as stuck valves and fouled plugs that will happen if you use 100LL. The TCP helps but is not a cure all. 

Eddie StewartElmore City, OklahomaN906C 108-3 Continental O-470

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Posted : 12/11/2019 7:58 pm

@dsrothmac-com

i bought a 40 gal portable tank with pump.  $350.  yea it's not cheap, but it's an asset that never loses value.  i mix mystery oil with it.  i also blend mogas 50/50 with 100ll when needed.  i pick up lead on my bottom plugs once in a while, witch burns clean at lean.  i use a cherry picker to load and unload from my truck.  (all done outside of hanger with extinguisher new by).  also added inline meter for $35.  love it.

 

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Posted : 13/11/2019 8:27 pm
lawheelock
Honorable Member

@mjwinsloyahoo-com

Marty,

A Franklin 150 or 165 NEVER needs 100LL added to mogas!  Franklins were designed in the 40s and originally certified with non-leaded 80 octane.  It says so in the Stinson Manual. 

Franklins were designed with hardened (stellite) valve seats that never erodes from not using lead in the fuel which is supposed to lubricate the seats.  Instead, due to the low compression of the Franklins, lead builds up on the seats which thermally insulates the exhaust valve from the seat which provides the cooling of the valve while it is closed conducting heat to the head and fins.  The end result often in less than 200 hours, especially in the 150 engine with weaker valve springs than the 165, is an overheated exhaust valve head and burning and subsequent leakage and the necessity to replace the valve.  With non leaded autofuel of 80 octane or higher the valve will easily last to TBO of 1200 hrs.  I know from more than 40 years and a couple thousand hours of experience!

Larry Wheelock, A&P/IAStinson 108 N584LW 180 LycTexas in Winter; Indiana in Summer

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Posted : 14/11/2019 7:28 am
lawheelock
Honorable Member

Marty,

PS.  You made a good choice with your tank purchase, you just don't need that 100LL.  I bought a tank and electric pump and totalizer years ago for my pickup truck.  Over the years I put more than 4,000 gallons through that system and I estimated a savings of at least $1.00 per gallon so I paid for both the tank and an old pickup truck many times.  I operated my Stinson with the 150 Franklin from 1968 through March of 2012 and then installed a 180 Lycoming.

Larry Wheelock, A&P/IAStinson 108 N584LW 180 LycTexas in Winter; Indiana in Summer

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Posted : 14/11/2019 7:32 am

@lawheelock

thanks for the information.  we are so paranoid about these engines.  i was just told that the franklin came with hardened seats. so cushion is not needed.  low compression causes lead build up,  and the springs are stronger on the 165 vs 150 reducing stuck valves.  burning mogas/non-ethanal is a proven correct move.  you guys are invaluable to the uneducated.  this information will be passed on. 

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Posted : 14/11/2019 1:55 pm
David Roth
Trusted Member

Thanks for the responses & information about fuel.  I'll be using non ethanol mogas exclusively unless away from home and the only option is 100LL in which case I'll add the TCP.  There's a station here in Albuquerque with the non ethanol for $3.60/gal.  I tested some & it is ethanol free.

What does the TCP do to make 100LL ok to use?

Yesterday I found a 120 gal. transfer tank with a 12 v, 15 gpm pump, filter,  hose & nozzle locally on Craigslist for $400.  I bought it & now need to get it mounted to a trailer.  I need to clean it out well and put a new filter on.  It was previously used for diesel.  I may also see about getting a bung welded on the bottom so I can thread is a valve for sumping it.

David

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Posted : 14/11/2019 2:28 pm
lawheelock
Honorable Member

@dsrothmac-com

David,

You may need to have your tank steam cleaned to remove any residue of the diesel in it.  After steam cleaning, it would be safe to weld a fitting in the bottom to be able to add a plug or valve to sump it.  When I prepared a tank for transporting mogas in my pickup years ago I welded in a drain port before I used the new tank.  My original tank already had  a drain plug in the bottom.

The history of TCP is that it was developed probably in the late '40s by Shell oil chemical engineer Al Hundre in order to have the big radial engines on I think the B36 have spark plugs survive without fouling long enough on 130 octane fuel to provide the long range that the plane was intended for.  It is a proven and FAA acceptable additive for all except turbocharged engines in aircraft.  After Shell no longer needed it for their 130 octane market, Al acquired the rights and formed Alcor and the rest is history. TCP is a lead scavenger.

Larry Wheelock, A&P/IAStinson 108 N584LW 180 LycTexas in Winter; Indiana in Summer

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Posted : 14/11/2019 4:21 pm

Since our engines so dislike lead I run my Stinsons on ethanol free Mogas. I use double the recommended dose of TCP when forced to run 100LL. I did check with the manufacturer and was told that a double dose does somewhat improve the lead scavenging but above that the increase in performance is not significant. I was also told that large TCP doses are not a problem for the engine or fuel, just costs you more money and above a double dose really does not do you any good. However, since it does not hurt your plane in strong doses, I make sure to have my error be on the too much side rather than on the too little side when adding the stuff to my tanks.

You asked how the stuff does the job of lead remission...... TCP is an abbreviation of a chemical name that is something like TriCloroPhosphate or something close to that. Alcor uses TCP as the name of their product but any additive containing the TCP chemical will work, even if the letters TCP are not in the name of the product. The only other product on the market is Decalin Runup. More on that in a moment, but first, how it works. This is, I am told, a somewhat oversimplified description but pretty much describes how the stuff works When untreated leaded fuel is burned in an engine the lead ends up "on the loose" in the combustion products and can deposit on the spark plugs, the valve seats and valve guides, and end up as grey sludge in the oil pan. (If you are cleaning an old engine inside and encounter the grey sludge be careful, lead has nasty health issues if it gets inside your body through a cut or raw spot in your skin).

When leaded fuel dosed with TCP is burned the lead joins with the chemicals in the TCP and forms tiny little lumps of lead phosphate. These little balls can be blown out the exhaust with the combustion products rather than the lead being deposited inside your engine. That is why an engine running TCP in the leaded fuel has white streaks aft from the exhaust pipes - the lead phosphate is that white-grey color.

The lead is not totally scavenged by combining with the TCP so even with treated fuel you will slowly build lead deposits inside your engine but you will build much less deposits and it will take a longer time to happen. Try to avoid using leaded fuel if at all possible. Use TCP when you do need to use leaded fuel.

I should also mention that TCP in the fuel helps to minimize the formation of lead deposits inside your engine. It does NOTHING to remove existing deposits, it ONLY minimizes the formation of NEW deposits. Some people mistakenly run no TCP in leaded fuel to save money and then add TCP for a couple of tank fulls when lead symptoms develop in their engine thinking that the TCP will clear out the lead deposits. NO! It will not remove existing deposits, it only helps minimize the formation of additional deposits. You need to add TCP to every load of leaded fuel you put into the engine.

I mentioned two brands of the stuff. Alcor TCP is FAA approved and has been around for a long time. It works and it's legal to use in your plane. However the carrier chemical "soup" that is used to get the TCP into a usable liquid form is nasty chemicals. The label has cautions about skin exposure and also recommends against carrying it via air transport.

The other available TCP product is Decalin Runup. It was developed by Decalin Chemical Company and reports are it does the job just as well (no better but no worse) than the Alcor product. Decalin used a nicer chemical "soup" to carry the TCP compound - the "soup" is basically high grade baby oil, they tell me - and is not hazardous to your body and is safe to transport by air. However, when Decalin looked at the cost and difficulty of FAA approval they elected to not bother so the stuff is officially marketed for use in Experimental aircraft only. It has been on the market for quite a few years now with no adverse reports from using it. The legality of using it appears to be an open question - I have heard convincing arguments that it is totally not legal to use it and also that it is not a big deal to use, that it's no different than adding a bit of Marvel Mystery Oil (also not blessed by the FAA) to your fuel or oil. You will need to make your own decision on that one.

So, you have a choice of two products. Both work just as well as the other. One (Alcor TCP) is FAA approved and not very safe to handle or transport by air. The other (Decalin Runup) is not FAA approved and is safe to handle and to transport by air. Decalin Runup also costs a fair amount less, by the way. Both products are available from the usual aircraft sources such as Aircraft Spruce, etc.

This was a long post. Sorry. Complicated subject to clearly convey. A disclaimer - I am not a fuel or engine expert. I am relaying what I have learned from talking to and reading from various sources. I believe the info to be correct but cannot promise total correctness or accuracy so do your own research to supplement and/or correct this if you want. The above is my two cents, for what it is worth.

Bob and Pat and the two Stinsons

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Posted : 18/11/2019 5:37 pm
David Roth
Trusted Member

@lawheelock

Thanks for all the information on lead scavenging additives. I have a can of TCP that came with the plane so will use that first.  It may take a while because I'll only be using it if I take the plane on a trip & can only get 100LL. 

I got a sump to weld onto the transfer tank I purchased but need to clean all residue of the diesel from the tank before moving forward with that.

I'll be happy to retire the 5 gal. cans!

David

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Posted : 19/11/2019 3:34 am

@dsrothmac-com

I will burden you with one more little trivia technicality, David. Most transfer tanks (and the pumps used on them, for that matter) are placarded for use with diesel fuel, kerosene and jet fuel. Very few are placarded for use with gasoline (of any type, avgas or mogas). I have been told by many folks who should know that the only reason for that is legal liability for the manufacturer -- gasoline is so volatile and so potentially explosive that the manufacturers just don't want the legal exposure just to sell to a small segment of the fuel transport industry. I don't know for sure if there might be a good reason other than liability to not label it for use with gasoline or not but I am told it is all about liability. I've known a couple of folks who have successfully used diesel transfer tanks for years to carry gasoline. I've never heard of a problem but that does not mean much either, it's a big world and there might be problems out there.

There are some tanks out there placarded for use with gasoline. A decade or so ago some neighbors moved out of my airpark and I bought their fuel trailer. It has a transfer tank and pump that are indeed placarded for use with gasoline. I got lucky and have a legal rig so I don't have to worry about the placarding on my tank/pump or vehicle.

One final point - my tank has a placarded capacity of 97 US gallons. That happens to match exactly the most restrictive limit I could find in US DOT's and my home state's regulations for the transport of gasoline. Above 97 gallons the carrying vehicle must have Hazmat placarding on it (the flammable cargo lables you see on transport trucks) and the operator must have certain Hazmat training and certifications. At 97 gallons and below there are no requirements that I could find. Again, I got lucky in that the fuel transport trailer I lucked into was legal in all respects.

If your transport tank is not placarded for use with gasoline and/or has a greater than 97 gallon capacity the odds of you getting into any trouble are pretty darn slim, I expect, but you should be aware of the possibility and be careful not to draw any scrutiny from a person with enforcement powers.

Bob and Pat and the two Stinsons

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Posted : 19/11/2019 8:25 pm

Just wanted to add,  I downloaded the locations of ethanol free gas stations into my Foreflight. That's if I need to divert someplace near a gas station. For planning a cross country, I carry three empty 5 gallon containers and I'll stop someplace near a ethanol free gas station where I can use an airport car or get a ride. It is a bit of a pain and time consuming, but it works and I can fly cross country. I do call ahead to make sure the station is still open and selling the ethanol free gas. I also call the airport to check on transportation.

This post was modified 4 months ago by John Cronin
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Posted : 20/11/2019 4:41 pm
David Roth
Trusted Member

@rjpustellgmail-com

Thanks for the detailed information on transfer tanks & pumps.  The tank I have has no placard on it at all although it is a commercially made steel tank.    I have a small utility trailer with 2 ft. high sides that I plan to mount it into -  bolted through the floor.  I understand that I am assuming a certain amount of liability transporting fuel this way and am okay with that and will do everything I can to minimize any risk.  It's the only viable option I have as there are no airports anywhere near where I live that have autogas.  Also doing the 5 gal. can thing is only going to work for the very short term.  

It appears that there is very little scrutiny of what people are hauling on the road around here.  At the station that has the nonethanol I see people filling 55  gal. drums sitting in the back of their pickup and driving away.

I hope to not have any problems fueling my plane this way.

David

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Posted : 21/11/2019 3:50 am

I expect you will have no trouble, David. I have been hauling fuel with my trailer mounted tank for over a decade now and have never ever been stopped or questioned. I have the luxury of a legal fuel carriage set-up but that cannot be determined by just looking at it so my lack of being stopped confirms your thought that it's a small risk.

It is so nice to have a stash of fuel available and a pump system to put it into the plane! The only time it is a bit of a drawback is when you fill the tank up at the gas station - my gas station proprieter loves to see me pull in with the trailer - he does not get a lot of $350 dollar sales in one stop at the pump!

Bob and Pat and the two Stinsons

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Posted : 22/11/2019 2:32 am
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