Oil firing in 1" scale

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Oil firing in 1" scale

Post by jscarmozza » Fri Oct 26, 2018 8:47 am

I recently acquired another 1" Atlantic, this one was originally oil fired and later converted to coal. The coal conversion wasn't done all that well, so I considered whether to redo the fire box, ash pan and grates for coal or go back to oil. From what I have read and what I was told by my club members, oil is a difficult fuel to manage in small scale. Not that I don't believe them, but I need to convince myself; so I made Nelson's oil nozzle to the dimensions given in his book (which I think is for 1-1/2") and tested it under air pressure with kerosene as the fuel.
I figured it would be best to start at low air pressure and go up, so I set the air regulator at 10 psi, I was surprised to see how well the fuel atomized and stayed around that pressure for the entire test. I lit it and after a few tries had a steady flame about 24" long starting about 3" from the nozzle. I then confined the flame with fire bricks to simulate the dimensions of the boiler fire box, and after a few adjustments had a strong steady flame in the box, but the flame still started about 3" from the nozzle. I played around with different air and fuel mixtures to see how the flame reacted, and concluded that there is a pretty narrow band of adjustment where this thing will work. Then just to see what affect a different fuel would have on the flame, I poured a few ounces of non-detergent motor oil into the kerosene. Totally different burn without touching the adjustment; heat went way up, within about 3 minutes the blocking fire brick on the end of box was beginning to glow red, fuel consumption was down, and the flame now started about 3/4" from the nozzle. So what does it all mean? It seems that everything affects the flame: fuel, air, size of combustion chamber, nozzle dimensions etc...and I'm sure that in the engine this nozzle would react differently than in the test apparatus. Bottom line question: is oil a practical fuel for a 1" engine? It seems like it will work, but it also seems that it's easily thrown off adjustment. I'd like to hear from anyone with oil firing experience. Thanks, John

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Re: Oil firing in 1" scale

Post by mattmason » Fri Oct 26, 2018 11:03 am

Watching this thread with high interest.
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Re: Oil firing in 1" scale

Post by blff cty lcmtv wrks » Fri Oct 26, 2018 11:16 am

back in my running days, my locomotive was an allen mogul. It was oil fired. I used diesel fuel and had great success with it, but it smoked quite a lot if you turned the oil up. I tried firing a few times on kerosene. it burned cleaner, but it would not keep up with demand. tried some jet-a fuel. not to good, either. where did I get the jet-a fuel? one of my train buddies owned a citation-2 jet. we syphoned some fuel out of the tank.

I remember running some tests with the railroad supply oil nozzle. we used kerosene and diesel. the kerosene would give a rather light yellow flame, with similar results that you describe. while standing about 10 feet from the flame, you could feel heat radiate from it.
with the diesel fuel, you had a much darker colored flame with a lot more radiated heat. I believe the diesel flame burned quite a bit closer to the nozzle.

try some diesel fuel and see what happens.

btw, I had two tenders. the front tender carried the oil, the back one carried water. It carried about eight gallons of oil. be sure to take the oil off the bottom of the tank, and put your oil control valve as low as you can get it. also run your oil lines as low as possible. you don't want them running up hill and down again. the working capacity of your oil tank will be reduced by highest point in your oil supply line. I also ran my oil line underneath the fire box. the idea was to heat the oil somewhat and make it vaporize better. whether that worked or not, I rally don't know, but the whole thing ran for years without any problem.

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Re: Oil firing in 1" scale

Post by Greg_Lewis » Fri Oct 26, 2018 11:20 am

While not an answer, I have in my notes a comment that several builders have suggested the hole in the steam nozzle of the Nelson burner is too big and the gap between the steam nozzle and the oil nozzle should be half the stated size. I made a burner that way and it works but I didn't do any comparisons or other tests. Just throwing this out for the common good.

The late Cal Tinkham ran half diesel half kerosene and he got more steam than he needed. But this was 1 1/2 scale.
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Re: Oil firing in 1" scale

Post by one_inch_railroad » Fri Oct 26, 2018 11:49 am

You should talk to the Eccentric Engineer AKA Anthony Duarte. He sells an atomizer for smaller fireboxes. I believe he has a couple of 1" engines that he oil fires and they seem to run and steam well.

https://www.eccentricengineer.com/atomi ... -fireboxes


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Re: Oil firing in 1" scale

Post by squandt » Fri Oct 26, 2018 12:10 pm

on the IBLS web site you will find under the steam engine parts heading an artical by Gordon Corwin about using oil to fire a 3/4 scale engine. You may find it usefull in your quest.
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Re: Oil firing in 1" scale

Post by jcbrock » Fri Oct 26, 2018 2:59 pm

Dave Johnson, who drops by here once in awhile, has a 1" Pacific that runs very well on oil. Not sure what kind of oil he uses.

My experience oil-firing was with a much larger engine, which would burn just about anything as long as you adjusted the atomizer, blower and firing valve appropriately. Some oils were not practical because their calories per gallon were too low. You could not build a large enough fire in the firebox to burn enough fuel to create the calories per hour you needed to make the amount of steam needed. The other issue were oils that were too thick to make it through the plumbing to the atomizer, we did not have an oil bunker heating system. The ideal oil to me was #2 diesel, when that was in the tank it was always an easy day.
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Re: Oil firing in 1" scale

Post by Marty_Knox » Fri Oct 26, 2018 4:12 pm

Find the article in Live Steam magazine, by Joe Monty, titled 'Oil Burning in a Small Firebox'. I think it was in the mid-80's.
It was a big help to me setting up an oil burner.

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Re: Oil firing in 1" scale

Post by Bill Shields » Fri Oct 26, 2018 4:16 pm

best oil atomizer is the one built by Bagley..designed more like a full size atomizer than the concentric ring idea...

http://ibls.org/mediawiki/index.php?tit ... Oil_Burner

I have not see it on a 1" engine.....flame length is a bit long unless you have a REALLY LARGE firebox.

There was an article in LS back in the 80's on making one from bolt together pieces...
Too many things going on to bother listing them.

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Re: Oil firing in 1" scale

Post by jscarmozza » Fri Oct 26, 2018 5:32 pm

Would a boiler be built specifically to be oil fired, with special fire box dimensions? This boiler is all LE, exactly the same as my other Atlantic, does that eliminate it from consideration? I also took a look at the fire box bottom that contained the original nozzle, as Greg Lewis said, the steam and fuel orifaces on the original nozzle are very much smaller than Nelson's, the fuel nozzle hole was a #60 drill hole. I was very surprised to see that the nozzle is pointed toward the fire door! How does that work? Can you open the fire box door during operation, and what happens to the engineer if you do? I'm also curious about how air enters the fire box and how it might be regulated. This boiler had a series of small holes around the perimeter of the box bottom and a rectangular opening with a sliding door to adjust air flow. Do you set the air intake for the nozzle and fuel you're using and just let it go? How do you regulate steam production during operation? Most importantly, I don't hear a chorus singing the praises of oil firing, I'm not discounting it yet, but I'm less enthusiastic about it then I was yesterday. Very interested in hearing more! Thanks.

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Re: Oil firing in 1" scale

Post by NP317 » Fri Oct 26, 2018 8:28 pm

Full sized oil-burning locomotives aim the fuel nozzle from front to rear.
The firebricks just under the fire door get heated red, and assist combustion.
After hitting the rear wall,the flames move upward past the fire door (which usually has a top-hinged baffle plate covering the opening),
and then forward up under the crown sheet and out through the fire tubes.
This doubles the burning path for more complete combustion, while distributing the fire throughout the fire box.
This radiant energy allows approximately 70% of the energy transfer into the boiler through the firebox sheets.
The fire tubes provide the rest of the energy transfer.

There is usually a fireman-adjustable air damper at the front of the firebox around the burner assembly, and another through the fire door.
Although the Climax we rebuilt also had air dampers along the rear sides of the fire pan.

Long burning paths are good, as are lots of flames in the fire box.

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Re: Oil firing in 1" scale

Post by ICC2411 » Fri Oct 26, 2018 11:04 pm

I would speak to Anthony at eccentric engineer about oil burners. He sells great oil burners that work well in the smaller locomotives. He has a little engine pacific in one inch scale that has a oil burner in it and it runs with no problems. I have seen him running with it at LA live steamers. I have seen another guy with the same burner in a small inch and half scale 0-4-0 without any problem, ran all day.

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