Author Topic: Gasoline vs. Coleman Fuel  (Read 3670 times)

Offline 90LX_Notch

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Gasoline vs. Coleman Fuel
« on: April 18, 2018, 10:48:49 PM »
Today I ran "Tiny" for the first time on Coleman Fuel.  I noticed a marked difference in heat, by touch, at both the cylinder and the head.  Previous runs were with 89 octane pump gas.  I found this to be opposite of what I expected.  I thought the Coleman Fuel would run cooler.  Why does it run hotter?

-Bob
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Offline b.lindsey

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Re: Gasoline vs. Coleman Fuel
« Reply #1 on: April 19, 2018, 03:06:51 AM »
Bob, not a precise answer by any means, but see
https://en.m.wikipedia.org/wiki/Coleman_fuel

Not a chemist, but I suspect the answer is to be found in the different chemical makeups of the two products. The octane rating of the Coleman is only 50-55 as noted. If I recall correctly, the higher the octane rating the slower burning it is. Thus premium gasoline actually burns slower to avoid pre-ignition or knocking in auto engines. So Coleman fuel at say 55 octane would burn faster and possibly more completely, which could account for the heat difference.

Bill

Offline Ian S C

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Re: Gasoline vs. Coleman Fuel
« Reply #2 on: April 19, 2018, 12:23:04 PM »
You might have to adjust the timing to fire nearer TDC with lower octane fuel. low octane fuel will destroy a motor designed for high octane, I'v seen it happen in a Cessna 185 with an IO-470 Continental engine, the pilot found he was low on fuel, so he filled up with farm supply fuel which was around 80 octane(normal avgas 100/120), twenty minutes later, barely able to maintain height he arrived at our airstrip, the crankcase was cracked, 4 out of 6 cylinders cracked, 2 pistons with holes in the crown, and just about everything else was stuffed. The engineering manager kept one of the pistons on his office desk as a warning to anyone who thought they could muck about with fuel.
On a little motor TDC Would not be to far off for a start.
Ian S C
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Offline gbritnell

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Re: Gasoline vs. Coleman Fuel
« Reply #3 on: April 19, 2018, 03:22:46 PM »
Hi Bob,
You're getting into chemical engineering here and most of us don't have that knowledge. I did some searching on the net and found this site which has the most comprehensive information about gasoline and burn rates. It's about a ten minute read but has some very informative information.
gbritnell
http://www.gonefcon.com/whatifdyno/combustion.htm
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Offline mnay

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Re: Gasoline vs. Coleman Fuel
« Reply #4 on: April 19, 2018, 04:57:56 PM »
I have a small Coles Hit and Miss engine.  I followed Bob Shores recipe for fuel using coleman fuel and 10% wd-40.  It runs great, does not carbon up and doesn't stink like regular unleaded gasoline.  I wanted to see what would happen with straight Coleman fuel.  It started and ran great, but within 20 seconds got very hot and the piston started to seize in the cylinder.  I was able to save it just in time as it was grinding to a halt.
I added the wd-40 back in the mix and it ran fine again, no heat, no stink.  According to Bob and from my experience the Coleman fuel alone did not have enough lubrication.

My two cents.

Offline Tennessee Whiskey

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Re: Gasoline vs. Coleman Fuel
« Reply #5 on: April 19, 2018, 05:53:11 PM »
Now old Cletus ain’t no petrochemical-enginerd, but, I’m pretty sure it has to do with the octane rating. As Bill stated, in regards to such, a higher octane fuel burns more rapidly and completely and “wicks away” the heat in a sense. Today’s autos can deal with the lower octane and ethanol enhanced fuels by the grace of the now computerized systems that can vary timing, fuel delivery, and such on the demand of various other systems that are monitoring temps, pings, and dings. I will also say that in the thirty years I’ve been selling fuel and for many of those years, working on the vehicles that bought it, the ones that paid up for premium, had way less problems  :shrug:  And yes Bob, noticed the same thing on my Red Wing.

Cletus

Offline 90LX_Notch

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Re: Gasoline vs. Coleman Fuel
« Reply #6 on: April 20, 2018, 09:36:13 PM »
Thanks gentlemen.  I wish I had a thermal thermometer to do some testing with.

-Bob
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Offline b.lindsey

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Re: Gasoline vs. Coleman Fuel
« Reply #7 on: April 20, 2018, 09:44:45 PM »
Bob, I have only run mine on Coleman with about 1-2% marvel mystery oil. While I can't compare it with regular gas, the Tiny doesn't heat up that fast and once the cylinder gets to the point I can't hold my finger on it I usually shut it down. Obviously depends also on the ambient temperature. The other difference with yours is that it isn't hit an miss so you are generating more heat from the constant firing every other revolution.

Bill

Offline Tennessee Whiskey

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Re: Gasoline vs. Coleman Fuel
« Reply #8 on: April 20, 2018, 11:08:20 PM »
When I first got the Red Wing up and running again after the painting, I was running it on Coleman with a drip oiler on the piston. As Craig Deshong stated: I gave it a good bit of oil and just let it run to seat the valves and rings. TBH, it got hot enough that I shut it down for a bit.  I then ran out of the Coleman and started using Shell 93 octane ( know a fellow that sells it  :Jester:) and was just amazed at how cool it ran. I could run a full tank through and still be able to lay my hand on the cylinder and hold it for a bit. I am really intrigued by Ian’s post on AvGas: think I’ll pop out to my local FBO and fill up a few cans of 100LL ( works great for my old motorcycle and car) and see how that works. I can guarantee you it’ll smell good  :lolb:

Cletus

Offline gldavison

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Re: Gasoline vs. Coleman Fuel
« Reply #9 on: April 21, 2018, 01:11:45 AM »
I run my engines on Aviation fuel with Marvel Mystery oil. My Tiny has never gotten to hot, and Av gas is half the price of coleman.
Gary
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Offline b.lindsey

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Re: Gasoline vs. Coleman Fuel
« Reply #10 on: April 21, 2018, 01:11:55 AM »
Thanks for the article link George. Some interesting information there. This whole discussion is an interesting one as well. Thanks for starting it Bob.

Bill

Offline b.lindsey

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Re: Gasoline vs. Coleman Fuel
« Reply #11 on: April 21, 2018, 01:14:38 AM »
Gld, are you mixing in any lubricant with the AvGas?

Bill

Offline lohring

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Re: Gasoline vs. Coleman Fuel
« Reply #12 on: April 21, 2018, 02:33:59 PM »
Model boat 26 cc and larger industrial style engines have raced with Coleman fuel for years.  The only issue is the low octane rating, around 50 to 55 octane.  It doesn't contain alcohol or other additives so it burns cleanly and doesn't damage  carb parts.  We did dyno tests on it as well as a variety of other "gasolines" and found no power difference on these low compression engines.

Lohring Miller

Offline Roger B

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Re: Gasoline vs. Coleman Fuel
« Reply #13 on: April 21, 2018, 03:47:27 PM »
I hadn't thought about the low octane rating of Alkylate fuel. When I ran the last trials on my horizontal engine it was starting to overheat with a load of 64W whereas previously it had run at 130W on 98 octane pump petrol. I will have to see if adjusting the ignition timing helps  :headscratch:
Best regards

Roger

Offline 90LX_Notch

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Re: Gasoline vs. Coleman Fuel
« Reply #14 on: April 21, 2018, 07:53:44 PM »
I had time to do a little searching and found the link below.  Although it does not specifically answer my original question with data that pertains to Coleman Fuel, I believe it explains what is occurring. 


https://www.topspeedparts.com/blogs/news/fuel-comparision


-Bob

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