Fuel for compression ignition engines (around 1 cc) - diesel model air plane engines

[jimbo7636]

I found a great webpage about how to mix fuel and techniques to start up small diesel compression ignition engines. But Im not sure of how long the mixed fuel can be kept and still be effective. Does it go bad after one day, one week, or what - stored in a metal tin can with lid ?

here is the webpage: https://www.eifflaender.com/engine-instructions

here is my break-in run on a ML Midge engine I machined and assembled - attached. i have additional videos of the engine running at full speed for several minutes but the files are too big for posting here.

 

[petertha]

I routinely would have commercial RC fuel for over a year in both plastic jugs & metal cans with no detrimental effect to performance. As long as the lid is well sealed. Mind you, I live in a dry climate. Methanol is hydroscopic, so is nitromethane but I believe slightly less so. It is possible the commercial fuels have some stabilizer goodies in there that might not be present in homebrew. I've heard its better to store in a smaller container to minimize air volume, but I never bothered. Nice running engine!

 

[Nerd1000]

I found a great webpage about how to mix fuel and techniques to start up small diesel compression ignition engines. But Im not sure of how long the mixed fuel can be kept and still be effective. Does it go bad after one day, one week, or what - stored in a metal tin can with lid ?

here is the webpage: https://www.eifflaender.com/engine-instructions

here is my break-in run on a ML Midge engine I machined and assembled - attached. i have additional videos of the engine running at full speed for several minutes but the files are too big for posting here.

I wouldn't store it for more than a year. This is because of the diethyl ether content, upon exposure to oxygen it slowly reacts to form diethyl ether hydroperoxide, which is a dangerous shock sensitive explosive. Evaporation can concentrate the hydroperoxide to the point where disturbing the container causes it to detonate.

For the same reason your containers should be absolutely airtight, to minimise oxygen exposure.

 

[jimbo7636]

I routinely would have commercial RC fuel for over a year in both plastic jugs & metal cans with no detrimental effect to performance. As long as the lid is well sealed. Mind you, I live in a dry climate. Methanol is hydroscopic, so is nitromethane but I believe slightly less so. It is possible the commercial fuels have some stabilizer goodies in there that might not be present in homebrew. I've heard its better to store in a smaller container to minimize air volume, but I never bothered. Nice running engine!

it sounds like the fuel you are describing is for a glow plug engine but Im not sure. Im asking about compression ignition diesel fuel. so this is for "vintage" engines I guess. but Im glad to hear you have been able to store fuel in both plastic and metal.

 

[jimbo7636]

I wouldn't store it for more than a year. This is because of the diethyl ether content, upon exposure to oxygen it slowly reacts to form diethyl ether hydroperoxide, which is a dangerous shock sensitive explosive. Evaporation can concentrate the hydroperoxide to the point where disturbing the container causes it to detonate.

For the same reason your containers should be absolutely airtight, to minimise oxygen exposure.

thanks for reminding me about peroxide formation. If I could get a couple of months of storage that should be more than enough. The smallest metal can I could find is 16 oz (473 ml) but I was hoping to just make 100 ml batches at least for now.

I guess once I get settled I could make up a large 450 ml batch to take with me when I go flying at a field somewhere.

 

[Bazzer]

I found a great webpage about how to mix fuel and techniques to start up small diesel compression ignition engines. But Im not sure of how long the mixed fuel can be kept and still be effective. Does it go bad after one day, one week, or what - stored in a metal tin can with lid ?

here is the webpage: https://www.eifflaender.com/engine-instructions

here is my break-in run on a ML Midge engine I machined and assembled - attached. i have additional videos of the engine running at full speed for several minutes but the files are too big for posting here.

Back in the 60's and 70's Eifflander used to recommend 33% each of the 3 main components and then some ignition improver, which is basically their running in mix.

I found that works great.

 

[jimbo7636]

Back in the 60's and 70's Eifflander used to recommend 33% each of the 3 main components and then some ignition improver, which is basically their running in mix.

I found that works great.

I agree with the formula. my question is how long can I store that mix? Right now I have 80 ml stored in a glass jar that is about 450 ml size. I put the jar into a box to keep it dark. im afraid the ether will evaporate too much into the air inside the jar, etc.

 

[Bazzer]

In my experience more than 12 months in a tightly sealed container, or just days in a bad container.

You have a lot of air volume in the container which is not good.

 

[petertha]

it sounds like the fuel you are describing is for a glow plug engine but Im not sure. Im asking about compression ignition diesel fuel. so this is for "vintage" engines I guess. but Im glad to hear you have been able to store fuel in both plastic and metal.

You are exactly right, I should have read more carefully.

 

[bluejets]

how to mix fuel and techniques to start up small diesel compression ignition engines.

There are other alternatives out there for fuel as, if like down under here in Aus, ether is almost unobtainable.
Mention ether and they are likely to call ASIO these days.
I have details on the alternatives somewhere, just have to find them.

I do have a dark brown glass 0.5 litre bottle of the "original" that has been on the shelf for around 30 years now, still works fine.
In fact, after the flood here, slooshed all the water out of the Victa after standing for 4 weeks....tried everything but no way it would fire.
Gave it a small amount of the aforementioned mix, pull and had to chase it around the block.
Smoke like nothing you ever saw but still in operation today. (bought new 1986)
Although, it does need a squirt of "start-ya-bastard" (yes true product name) down the air breather tube at startup.

 

[f2cf1g]

Diesel fuel will last indefinitely provided (a) that the container is airtight and (b) that the container is opaque or nearly so, as per Bluejets brown bottle. Glow fuel is tolerant of daylight, diesel is not. Nice Midge, mine runs well. In your 2nd video yours sounds overcompressed.

 

[Steamchick]

As a teenager Diesel fuel was 1/3 each paraffin, oil, ether. When I cranked the engine the wrong way in the shed, the ether accumulated and sent me to sleep....
So I bought a "starter spring" - which showed me the right way to crank the engine - and it was fine!
K2