Diesel conversion

I am inclined to agree with aspeed here-the normal 'go to' solution for diesel users who can't obtain ether is to use proprietary 'engine cold start' spraycan products-of which John Deere is the one generally mentioned-due to its 80% ether content. The catch here is that that product is SPECIFICALLY FOR COLD CLIMATE USE. There are products made for engine starting in tropical climates....unfortunately these are much much lower in ether content-eg 'start ya bastard'-an Australian product-is only 25% ether....that is simply too low to be of any use-by the time you have added lubricant-you are down to 20% ether at best-and even lower if you use a higher % lubricant content. I would just about guarantee-based on personal experience in Bougainville-that any such product you can obtain in Fiji will also be a similar low ether type-Fiji being a very much tropical country.

You have about 2 choices-befriend a high school science teacher in Fiji, who can access ether (and methanol!) through their employment; or similarly befriend a lecturer at the University of the South Pacific. In that event you should be able to mix up either diesel-or straight glow fuel. In the case of straight glow (ie 80:20 or 75:25) you can compensate for the lack of nitro by going to a hotter plug...that in turn means using a non OEM plug adaptor head-either a 1/4-32 or one of Kamtechnic's Nelson or turbo plug ones....I'd go for the turbo on the basis that while there IS such a thing as a HOT nelson plug, there is a much bigger heat range of turbo plugs.

This approach should work for 049/051, 074, 09 and 15 coxes....I doubt the efficient functioning of 020s on straight fuel...

ChrisM
'ffkiwi'

Iceberg wrote:hi Guys
Been posted to Fiji in November. Have tried to obtain nitro fuel from US/Australi/New Zealand so far all failed. I tried a few test runs with Ethanol 80% and castor 20% ran ok sort of

What does everyone think?

Haven't had a flight in months.....NOT GOOD!!!!!!!

Ice from Fiji with NO NITRO FUEL FOR THOUSANDS OF MILES!!

éthanol ? You could convert to gasoline I myself tested an interesting possibility I believe that an appropriate mix could give good results you can surely find a way to spice gasoline where you are nitro propane or even pure alcohol mabe plane gasoline ?? I used a very hot glow plug which could work with gasoline it is specially designed for 4 stroke models which works with gasoline an OS g5 if I remember correctly but you will have to use an old glow plug and modify it perhaps with two seal on an adapter could do but I think the adapter for turbo plug could be a good choice you could maybe find a turbo plug that is hot enough this vidéo is a cox runing wit gasoline and little nitro propane and methil hidrate

same idea as I had
but I use a full spark setup

This Australian webshop claims to ship glow fuel internationally

http://www.modelengines.com.au/about-us/

With some castor bought on Fiji from pharma or similar shops, the synthetic oil based Aussi fuel may be blended suitable for COX engines.

Iceberg wrote:
Who has really spent ANY time with diesel conversions? Are they worth the hassle? I fear they are low rpm and I don't want to buy new cranks and refit everything on my sweet running jewels. Unless worth the effort.

I have converted Pee Wee and Queen Bee engines to diesel. These actually run much better on diesel than on glow fuel, in my opinion. On glow fuel one has to use relatively small props at high rpms, this give a rather low thrust and doesn't work well on models that have a higher drag, from a landing gear etc. On diesel on the other hand, one can use larger props and thus get a higher trust plus a better fuel economy. On Diesel I usually prop the engines for about 10-11 krpm (on the ground) at full throttle, this give a very good thrust at lower air speeds and a more scale-like flying. The exhaust note is also much softer, compared to glow, and overall it is a much more pleasant flying experience, not only for me but also for the others at the field.

The down-side with diesel fuel is in the fuel itself, it is very important to have a good fuel mix. This ensure that a low compression ratio can be used, in fact it only needs to be slightly higher than for glow fuel. For the right fuel mix you need to have pure ether and a bit of DII, together with castor oil. This is not easy to obtain and blend one-self, so beginners are best of with commercial fuel blends. Otherwise there is a high risk of breaking cranks etc.

I would also recommend to not use the Teflon-disc styles of conversion heads, these are not worth the effort (they leak and give erratic runs) and will also risk damaging the engines from over-compression. The blue heads from RJL/Meccoa are much better, they seal with an o-ring. Below is one conversion that turned out pretty good, the queen bee with a .09 head from RJL. On glow the max prop load is about 6x3, so high rpms and low thrust, while on diesel fuel one can even use an 8x4 prop and it now pulls much larger planes with ease.

Kris, your diesel conversion of the under-rated Cox .074 Queen Bee is fantastic! Turned it into a practical runner. It's heavier weight for its power (4 oz.) limits as you point out, what planes it runs on glow best.

Thanks Andras
I'll check the hobby shop in Australia. Already other shops accepted the order and then shortly there after cancelled. However will try this one thanks my friend. I hope Budapest is good and spring is soon there!

Ice

Thanks Darren, spring here is around the corner, and to make the transition from winter  smoother, we will spend a week under Thai sun that you lived under,  in 10 days.

Check with that Aussi shop on their HAZMAT policy, there should be ways to ship glow fuel into Fiji!

I know what it feels like being deprived from flying our  COX engines..with the mild winter here I did not stop flying as long as the air temp was at least +5C. Below that temp my hands start to shiver with the sticks on the radio becoming hard to control..