Legalities, conveniences (or otherwise) of mogas in a 14-13?
- Thread starter kitepilot
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Dan Cullman
New member
Please post the NTSB report.
I have had vapor lock in my 14-13, a couple times....with avgas....and I didn't crash.
Dan
I have had vapor lock in my 14-13, a couple times....with avgas....and I didn't crash.
Dan
Larry Lowenkron
New member
Mogas now has a lower vapor pressure than it previously did. This reduces the chance of vapor lock (say thank you to the Clean Air Act). Unfortunately, we now also have to contend with ethanol in it unless you are lucky enough to live in a place where non ethanol laced gas is available.
Dan, I too have had vapor lock with 100LL. Taught me to ALWAYS have my electric fuel pump on during TO and LNDG!
A few years ago I talked to both Peterson and Earl Lawrence when he was at EAA about either Peterson or EAA getting an STC for our planes. There is one for the Stinson 108 series with Franklins, but not Cruisairs. They were sort of opened to it, if we could get enough of us to front end the cost...never happened. I would think that with fewer than 150 of us flying, it won't happen. Be interesting to see what will eventually replace 100LL...?
Dan, I too have had vapor lock with 100LL. Taught me to ALWAYS have my electric fuel pump on during TO and LNDG!
A few years ago I talked to both Peterson and Earl Lawrence when he was at EAA about either Peterson or EAA getting an STC for our planes. There is one for the Stinson 108 series with Franklins, but not Cruisairs. They were sort of opened to it, if we could get enough of us to front end the cost...never happened. I would think that with fewer than 150 of us flying, it won't happen. Be interesting to see what will eventually replace 100LL...?
Dan Cullman
New member
Almost every locality has non-ethanol fuel available.
To find out, check the website "purefuel."
Even the Peoples Socialist Republic of King County Washinton has some.
Dan
To find out, check the website "purefuel."
Even the Peoples Socialist Republic of King County Washinton has some.
Dan
blimpy
New member
Ethanol is such Very Bad News... that it is pure stupidity to use any mogas in any proportional mix with av gas
100 LL is perfectly safe to use in your franklin... do what everybody with a Lycoming does...
routinely lean on the ground... lean even at 2000 feet. Just don't over-do it at low altitude.
A little dab'l do ya.
Pure gas only lists two places in California where no-lead auto gas is available
Eureka are and Riverside.
and guess what it is $6 bucks plus a gallon. 50 cents more than av gas.
No point what-so-ever.
Franklin OK'd TCP which will take care of lead deposits nicely.
Buy some , Use it.
Forget car gas until we can get some market priced no-lead without alky which is corrosive, absorbs moisture from the air,
creates gum, and is generally cheap-ass crap.
Av gas is MilSpec gas. It wont gum up your fuel system if it sits idle for a year or even two.
Lawnmower gas wont last 3 months before it turns green, and eats a hole in your expensive aluminum tanks.
end rant... and screw the EAA types who swear alky car gas is safe ! Nut Cakes !
100 LL is perfectly safe to use in your franklin... do what everybody with a Lycoming does...
routinely lean on the ground... lean even at 2000 feet. Just don't over-do it at low altitude.
A little dab'l do ya.
Pure gas only lists two places in California where no-lead auto gas is available
Eureka are and Riverside.
and guess what it is $6 bucks plus a gallon. 50 cents more than av gas.
No point what-so-ever.
Franklin OK'd TCP which will take care of lead deposits nicely.
Buy some , Use it.
Forget car gas until we can get some market priced no-lead without alky which is corrosive, absorbs moisture from the air,
creates gum, and is generally cheap-ass crap.
Av gas is MilSpec gas. It wont gum up your fuel system if it sits idle for a year or even two.
Lawnmower gas wont last 3 months before it turns green, and eats a hole in your expensive aluminum tanks.
end rant... and screw the EAA types who swear alky car gas is safe ! Nut Cakes !
Dan Cullman
New member
Minor point......6 places in CA.
I don't think Ca. uses ethanol as an oxygenator. It's my recollection that something called MTBE, or some thing like it is used and it is worse than ethanol.
Anyway, ACM wanted you to use unleaded fuel, which was available at the time. 80/87 didn't have enough lead to bother, but 100LL or 100/130 does. Yes, TCP helps but is fairly expensive.
Dan
I don't think Ca. uses ethanol as an oxygenator. It's my recollection that something called MTBE, or some thing like it is used and it is worse than ethanol.
Anyway, ACM wanted you to use unleaded fuel, which was available at the time. 80/87 didn't have enough lead to bother, but 100LL or 100/130 does. Yes, TCP helps but is fairly expensive.
Dan
Larry Lowenkron
New member
MTBE is not used because of ground water pollution. It has been quite a while since it was used. Actually it wasn't that bad as a substitute...in fact it was approved under both Peterson and EAA stcs. Ethanol is not.
SoCalPlaneDoc
New member
Kite's question was about legality.
Without a statement in the TC, or existence of a properly executed STC, it's not.
The issues with ethanol are well documented however...
I did a pre-purchase annual on a -1 Stinson where the owner reported occasional effects of vapor lock when I discovered the entire fuel system forward of the firewall heavily wrapped in insulation. The inspection revealed a bent intake pushrod which showed signs of occasionally popping out of the rocker socket - preventing the valve from completely closing. When I asked him what it did when it had "vapor lock" he told me it would stumble, lost power, and generally run rough for a few seconds... I bought that Stinson on the spot for a very low price, slipped a straight pushrod in it, ripped out all that insulation and put 470 trouble free hours on it before I let it go..
another guy with a Cherokee brought his plane to me telling me he had vapor lock issues.. when I asked why he thought that he told me all he has to do is turn on his boost pump and it goes away.. I found his engine driven pump severely worn...
Vapor lock often falsely gets blamed for other problems.
That being said, boost pump on during any low-level ops is always a prudent practice.
Without a statement in the TC, or existence of a properly executed STC, it's not.
The issues with ethanol are well documented however...
I did a pre-purchase annual on a -1 Stinson where the owner reported occasional effects of vapor lock when I discovered the entire fuel system forward of the firewall heavily wrapped in insulation. The inspection revealed a bent intake pushrod which showed signs of occasionally popping out of the rocker socket - preventing the valve from completely closing. When I asked him what it did when it had "vapor lock" he told me it would stumble, lost power, and generally run rough for a few seconds... I bought that Stinson on the spot for a very low price, slipped a straight pushrod in it, ripped out all that insulation and put 470 trouble free hours on it before I let it go..
another guy with a Cherokee brought his plane to me telling me he had vapor lock issues.. when I asked why he thought that he told me all he has to do is turn on his boost pump and it goes away.. I found his engine driven pump severely worn...
Vapor lock often falsely gets blamed for other problems.
That being said, boost pump on during any low-level ops is always a prudent practice.
glennhake
New member
Pilots/Owners/Flying Club have been using mogas at our field in Franklins, Lycs, and Cont engines for more than 20 years with good results and about $1.25 cheaper than avgas. Farmers around here demand straight mogas so we have no problem getting it for our fuel farm before the additives are mixed into it. With new engines there is a valid argument avgas may facilitate exhaust valve seating for first few hours in some engines, otherwise there is no documented long term advantage for avgas or against mogas. Ethanol or alcohol are prohibited and easy to check for.
About 25 years ago I had a document about obtaining a 1 time mogas STC for aircrafts like ours where the numbers don't justify the normal STC process. It involve heating the fuel to 120F (???) and and flying to 10,000 ft amongst other things. I lost it about three moves ago. Something may still be out there.
About 25 years ago I had a document about obtaining a 1 time mogas STC for aircrafts like ours where the numbers don't justify the normal STC process. It involve heating the fuel to 120F (???) and and flying to 10,000 ft amongst other things. I lost it about three moves ago. Something may still be out there.
Larry Lowenkron
New member
I believe it requires using high vapor pressure gas (Alaska winter time gas or ASTM D4814 Volatility Class E) in an environment like Arizona in the summer.
blimpy
New member
If you have access to no lead mo-gas without alky.. mechanically it will work in our franklins.
As stated.. vapor pressure is a real issue.
Legally - you don't wanta go there unless you take the whole airplane experimental.
Peri-mental is something different. :lol:
---
Speaking of which - Lead was very much a part of the basic design consideration in most currently flying
aircraft engines.
It is an important valve stem and valve seat lubricant.
Engines not designed for no-lead suffer major top-end problems when run on fuel without lead.
Valve seat erosion ( sunken valve heads)
Valve guide accelerated wear.
Those are the two obvious problems you can see and feel in the cylinder heads of engines run on Propane, Natural Gas,
or No-Lead Fuel.
Recently the peri-mental :lol: RV-4 that burns California ethanol laced Mo-Gas- owned by an octogenarian gentleman -had it's Lycoming engine torn down on the ramp.
During the weeks ( ! ) it was apart I got to take a gander at it's failed cylinder, piston, and rod.
Nasty !
The thing had a noticible miss and backfire the last few times it was flown ( !!! ) - so I was anxious to see what was wrong.
1. The exhaust valve was deeply sunken in the head.
2. The stem and guide were badly eroded and of course loose.
For whatever reason ( geezeritus ? ) the bore was badly scored, the small end bearing had a big chunk out of it,
and the piston and rings were also toast.
The ignition system on this thing is also beyond creative... so who knows how many other variable are involved.
But the gent was totally unaware of the valve problems involved in running an 0-360 without lead or suitable substitute
My apologies to all pilots senior to myself still flying with wits intact.
As stated.. vapor pressure is a real issue.
Legally - you don't wanta go there unless you take the whole airplane experimental.
Peri-mental is something different. :lol:
---
Speaking of which - Lead was very much a part of the basic design consideration in most currently flying
aircraft engines.
It is an important valve stem and valve seat lubricant.
Engines not designed for no-lead suffer major top-end problems when run on fuel without lead.
Valve seat erosion ( sunken valve heads)
Valve guide accelerated wear.
Those are the two obvious problems you can see and feel in the cylinder heads of engines run on Propane, Natural Gas,
or No-Lead Fuel.
Recently the peri-mental :lol: RV-4 that burns California ethanol laced Mo-Gas- owned by an octogenarian gentleman -had it's Lycoming engine torn down on the ramp.
During the weeks ( ! ) it was apart I got to take a gander at it's failed cylinder, piston, and rod.
Nasty !
The thing had a noticible miss and backfire the last few times it was flown ( !!! ) - so I was anxious to see what was wrong.
1. The exhaust valve was deeply sunken in the head.
2. The stem and guide were badly eroded and of course loose.
For whatever reason ( geezeritus ? ) the bore was badly scored, the small end bearing had a big chunk out of it,
and the piston and rings were also toast.
The ignition system on this thing is also beyond creative... so who knows how many other variable are involved.
But the gent was totally unaware of the valve problems involved in running an 0-360 without lead or suitable substitute
My apologies to all pilots senior to myself still flying with wits intact.
Larry Lowenkron
New member
Larry, I keep seeing people talk about lead being used as a lubricant for valves, etc, but have never seen it referred to as such in any real engineering publication. My understanding is that lead was added to increase Octane No. to allow higher compression engines operate without detonation. The ASTM spec for 80 Octane actually has a Pb spec of zero to 0.5 ml/gal. Regarding the Lyc you described, it does indeed sound like there were many variables that may have contributed to its condition. I could see ethanol may contribute to screwing up engine components that may be soluble in it but wonder how else it contributes to engine wear (destruction).
LL
LL
Dan Cullman
New member
All,
Somewhere in my archives, I have a letter from Harry Zeisloft [sp.?] who was an engineer with General Motors and advisor to the EAA's mogas STC program. He stated pretty much which Larry L. posted. Tetraethyl lead is an octane booster.
Dan
Somewhere in my archives, I have a letter from Harry Zeisloft [sp.?] who was an engineer with General Motors and advisor to the EAA's mogas STC program. He stated pretty much which Larry L. posted. Tetraethyl lead is an octane booster.
Dan
SoCalPlaneDoc
New member
Larry Lowenkron said:
Ditto. Lead does nothing other than slow down the burn rate, allowing more *time* for the energy to push on the piston. It does nothing for lubrication - that's a very old misconception that wont seem to die.. Lower compression engines rarely need it, Franks will often have plugs foul due to lead. I actually have a little bottle with a collection of tiny lead balls I picked out of my plugs when I had a Frank.
People always seem to find examples of premature wear in engines using leadless fuel and pounce on that as the cause..
of course, once people thought that a pile of garbage in a corner was how rats were created...