gas mystery

[tony marks]

three yrs ago the timing belt in my
festiva went . so i parked it w plans to make a dune buggy or somethin out of it ,later. welldecided to fix it . she cranks right up an purrs like a kitten.
relevance to this forum is ,how does 3 yr
old gas that really smelled like vineger,
still run the little 4 cylinder so smooth.
of course ive added stabelizer and half tank of mid grade now. but ,sure surprised me.
ps clean air ,oil an fuel . she had 216000
miles when i parked it.still dont use oil.

 

[John in MA]

I've had cars sitting a while like that. If there wasn't too much in the tank, I just fill it up with new gas. No problems so far.

 

[HUSKYMAN]

The problem is when you put a load on the motor it will detonate like a mother. Old gas is MORE explosive then new gas. After sitting that long the tank probably is full of water from condensation so put a couple bottles of dry gas in it and top it off with fresh gas

 

[Tony Snyder]

Drain that old liquid out of there. you probably have some water and dirt to contend with. Lucky so far, but you may not remain lucky.

 

[sedanman]

Here's my two cents. The car has an evaporative emissions system to prevent or at least slow down the duh, evaproation of the fuel, chainsaws and gas-cans do not. There is a much larger quantity of fuel in the cars tank than you could ever squeeze into a saw. Old fuel first looses its "light aromatics" these are the components that make starting the engine easier. With a multi-cylinder engine it's easier to get things goin wit depleted "light aromatics" than it would be to start a single cylinder chainsaw. Kerosene has almost no light aromatics but during WW2 members of my family fuel the cars with it as gasoline was rationed, the car had to be started on gasoline dribbled down the carb but it would run on kero. I beleive slightly stale gas has a HIGHER btu content than "fresh" gas, I will consult with a friend of mine who is a retired engineer fromTexaco to verify this.

 

[Methoss084]

Sedanman, I believe your right. As the VOC's or Volitile Organic Compunds in gasoline evaporate away, the after product "stale gas" will have a greater BTU value due to it's slower burn rate or flame front , similar in characteristics to K1 Kerosene. Those old cars and farm tractors would run on Kerosene with no problem as long as the engine was first warmed up to temperature with gasoline.
Josh

 

[tony marks]

i appreciate the advice . i did put some additives ,to boost it a bit nd take care of any water . i will probabely run it this week and put a new fuel filter on ,even tho shes running smooth.
took her on my sat running yesterday 150 miles . litte thing get 75-80 quicker than anything i got.. not that i would ever let it go past the speed limit. thanks again.
ps the only reason i mentioned it here is we hear so much about bad gas in our chainsaws.

 

[eyolf]

Methos is partly right, but partly wrong. Years ago lots of Farm boys ran kerosene or "tractor distillate" in their tractors and farm engines, but the stuff had a really low anti-knock rating. Many farm engines came with special manifolds designed to preheat the mixture to allow better vaporization of the fuel, and some also had a system that injected small quantities of water along with the fuel to partly quench flame propogation (control knock). This also had the added bonus of keeping combustion chamber deposits down.

One thing many farmers might remember is that oil and spark plug use went up with distillate fuel...the plugs fouled, and the oil got diluted with combustion by-products really fast, soon coking up ring grooves and destroying the oil rings capacity to drag oil back down to the crankcase. Engine life suffered, and while distillate was cheaper, only the really old-design engines with huge pistons and very slow speeds were able to economize with the use of distillate.

That doesn't have a whole lot to do with chain saws or little cars...there's not a whole lot of similarity with a 634 cu in two cylinder tractor engine and a chain saw or small car.

But, some of the lighter fractions do havew fairly high octane ratings, and as they evaporate, do affect the octane of what fuel is left. As well, over time, some polymerization takes place...as some molecules oxidize slowly, they are attracted to other molecules, and form longer chained or branched chain isomers...many of which have undesireable effects on burn rate.

I've got an old Ford pickup here on the farm, that has sat unused since 1992...I decided to clean up behind the barn last summer and moved it. It started, too...leaky rear main seal notwithstanding...and idled fairly well given the old gas. ???? thing sounded like a hail storm on a tin shed roof if you put any load on it though.

I didn't care; I retarded the timing enough to drive it around a little until it over heated. Im sure Mr Marks doesn't care if his old car pings and knocks a bit until he burns the old gas out.

One of the worst problems with chain saws has to do with the dighragm carbs...they won't meter correctly if there is water in the fuel or even if the fuel is old, especially if the fuel has gotten old in that carb. Even a little crud in there is enough to lean things out dramatically, and even a little leaning out is a death knell to a high performance two stroke.

 

[tony marks]

i would agree. with the high performance saws of today. theres little
room for error in the lub or air fuel mixture. lot o differences between
say 6-8 thousand and 12 -16 thousand.
just my guess tho.

 

[Methoss084]

Maybe after restoring to many JD's I missed something about farm tractors? And maybe I missed something about gasoline after testing spill sites for 10 years. oh well.

 

[tony marks]

sound like u know what u talkin about to me. not strokin nobody ,but what u guys
know about the combustion engine,
well lets just say i understand a little here an there. sure does open some windows of knowledge.

 

[eyolf]

Maybe I owe methos an apology...I didn't mean to offend him or anyone else. I still stand by my assertions regarding K1 kerosene, though.

K1 is refined with tight controls over two important things; cyclic hydrocarbons (ring hydrocarbons like benzine are carcinogenic) and sulfur content (those who have been around a kerosene cook stove remember the burning eyes and runny nose...). Cetane rating (ability to ignite readily, as in diesel engines) isn't as important as in diesel #1, and there are wider limits to flash point than jet fuel. None of these fuels have any attention paid at refining to anti-knock rating; the anti-knock rating can be as low as 45, up to about 70 with this class of fuels. K1 was originally desogned to be used in products like salamder heaters, "Kero-sun" heaters, etc., where it was tough to put up with the large amounts of combusation by-products indoors.

As a restorer of old John Deere tractors, Methos is certainly aware of the water valve on the old "D" John Deere. After the 2nd world war, most tractor makers actively discouraged the use of these low-grade fuels, as gasoline was nearly as cheap, actually provided more power, and had fewer associated problems. None of this is particularly important today, as these old tractors are mostly being babied and cared for, only used on parade days and at farm shows.

I have burned Kerosene and #1 diesel in my 1927 Farmall regular just for kicks, which seems to handle it fairly well, as well as f12 and F20's which do not fare as well. They will exhibit spark knock under load, and exhaust stinks like crazy. None of my tractors has the water feature, which was supposedly not as necessary with overhead valves and ricardo-style squish band as it was with flathead engines like the Fordson, which had a separate water tank for this purpose.

The manuals I've seen for Farmalls all caution that power ratings are to be reduced somewhat with the use of distillate fuels, and my experience bears this out...the Farmall "regular" will pull 2 16's in 3 year hay stubble on the flat (2nd gear), but labors on a hill. With #1 diesel, it needs to be in 1st gear, and knocks a lot; the tractor will pull steadily down to about ( a guess) 350 rpm on gas, but dies out at a higher rpm on kerosene.


I will not say anything about your experiences testing spill sites, as I do not know what you were testing for. It is likely that you do know far more than I do about what hapens to petroleum products as they migrate through the soils and air.

 

[Methoss084]

Eyolf, I believe I owe you an apology as well. I was having a bad day and did not mean to sound like I was throwing a hissy fit. I haven't restored any JD "D" models (I wish). But I have had my share of "A" and "B" rustorations. I haven't had much in the way of experience with water injection except for seeing them on "OLD" diesels or reading about them. We used to rent out 500K & 750K BTU Kerosene heaters. " God I hate the smell of K1 now"! I know that K1 or White Kero was origianlly made for household and camp use because of its low carbonmonoxide and odor output per BTU. As compared to other fuels except for LPG or CNG. The Highest Cetane rating I've ever seen at the pump for over the road fuel is a 45 Cetane rating. Knock Knock