diesel engine microlight pendulum

[olivcody]

Hello,
after going through the subject on the dieselis and gazaile2, I would like to have your technical point of view on my subject.

indeed, I would like to self-build a pendulum ulm equipped with the cdi engine of the smart fortwo developing 40hp at 4800rpm or see 51 on the 2nd generation smart and 100Nm at 1800rpm. the weight would be about 70kg
my questions are:
can it run on oil (with a little diesel to heat and clean the engine),
what performance can I expect (cruising speed),
how should the propeller pitch be dimensioned (to have the best cruising speed efficiency),
what would be the impact on the rise in altitude (always in relation to the step).
other questions will surely come according to your ideas.

please

[Christophe]

This subject will interest the world !!

Coincidentally, I was talking about the diesel engine of the smart in aviation in Maloche this weekend even when we visited the very interesting museum-hangar of La Ferté Alais: http://www.ajbs.fr/

No, an hdi will have trouble running on oil, at least not 100% durably.

For the rest, the fact that it is a diesel engine does not change much, it will simply run slower for the same torque.

So the propeller setting, in direct drive, should, I think, be increased.

[Macro]

idhp ramp common to the HV there are ...

[Christophe]

Yes there are but at 100% it does not last long ...

On some "idhp" you can not even put "red" or poor quality GO (Eastern Europe) without risk of failure ... that is to say!

On our (118d) it marked "No bioadditive" ... and I don't think that this is a stroke of the oil lobbies ...

[oiseautempete]

indeed, I would like to self-build a pendulum ulm equipped with the cdi engine of the smart fortwo developing 40hp at 4800rpm or see 51 on the 2nd generation smart and 100Nm at 1800rpm. the weight would be about 70kg
my questions are:
can it run on oil (with a little diesel to heat and clean the engine),
what performance can I expect (cruising speed),
how should the propeller pitch be dimensioned (to have the best cruising speed efficiency),
what would be the impact on the rise in altitude (always in relation to the step).

hum: 70kg + the essential reducer (4800tr is much too fast) it's heavy ... A pendulum microlight is a drag trap and only works well with little power if it stays light (depending on the good principle of Henri Mignet), if it is heavy it takes power to have a correct climb and 40hp it is little for a two-seater commuter, there is only to see the modest benefits of a motorized commuter 503 (52hp) yet much lighter.The smart diesel has a lot of torque thanks to the turbo, but it is only of interest for cruising ...
The propeller pitch, if it is rather weak, it will go up to the walls, but row on a cruise, if the pitch is rather strong, the cruise will be good, but the climb will be poor, so it's all about finding the right compromise according to the use we make of it and the terrain we practice ...
With an unknown motor, you need an adjustable pitch propeller which allows you to grope for the correct compromise ...
The 3-axis diesel aircraft, very well profiled like gazaile are certainly efficient in cruising, but their climb is modest and it takes a lot of runway to take off: on a small traditional ulm grass field, not too well maintained and surrounded by trees you can forget this kind of option, unless you have suicidal tendencies ... on well-paved hard tracks why not ...

In my umble opinion, to fly from time to time with relatively few hours of flight (it is rare that we do more than 50h per year, the average of pilots is much less), no need to s 'emm ... with diesel and messy adaptations, it is better to choose a good ulm engine not too greedy, if you fly not far away a modern 2-stroke (ex: Hirth injection, 12L / h in eco crosiere for a 70hp), if you fly a lot over large distances, a good 4-stroke HKS700E (60hp) generally does the trick and it eats ~ 10L / h or less ... if you absolutely want tinkering, a reliable motorcycle engine also does the trick, a lot of Suzuki bandit mills are used (fairly easily found in motorcycle breakage), but you need a good reducer ...

[chatelot16]

it still makes more sense to put economical oil and fuel in road vehicles than in flying machines

it takes at least 1.2 times heavier vegetable oil than diesel to make the same energy: on the road it has almost no importance, but in the air it's a shame

but then the techno of the hdi interests me: where is the problem? this is what does not hold with vegetable oil?

if it is only the injection system that does not hold it does not matter: the continuous pump system and electrically controlled injector is anyway not a reliable solution

the equivalent of hdi to run high efficiency diesel is the pump injector

on the other hand if it is in the cylinder that the vegetable oil poses problem the injector pump will do nothing better

[oiseautempete]

but then the techno of the hdi interests me: where is the problem? this is what does not hold with vegetable oil?

if it is only the injection system that does not hold it does not matter: the continuous pump system and electrically controlled injector is anyway not a reliable solution

the equivalent of hdi to run high efficiency diesel is the pump injector

A pump injector system is not much more resistant than the common rail: the pressures are even higher. The viscosity of the oil, even rapeseed (the most fluid) creates constraints such that the pump and the injectors fart ... by car if it farts, you stop at the edge of the road, in an ultralight, especially pendulum (finesse 8 or less), if you are above a non-posable area (and there are relatively little in my very rugged and wooded corner ...), it's better to avoid breakdowns: it's too stupid to lose your life (and possibly kill your passenger) for saving candle ends ...
For info: the electromagnetic controlled injectors, there is more than that today, even on trucks, the pump injectors are abandoned (incompatible with Euro 4 and 5 standards) and are no longer used on some working engines or carts because cheaper ...

[Christophe]

+1 chateau
+1 bird

But there is not THAT the viscosity which makes a fuel, there is also the cetane (among others) much lower oil / GO (around 30 against 50) ... the best oil on the criterion of cetane is l palm oil (cetane at 45-48 against 50-52 for GO) but it is solid up to 30-35 ° C (see more) ... it's a bit problematic therefore ...

So I think vegetable oil is to advise against (prohibit?) therefore in aeronautical use unless you use an engine DESIGNED FOR ...

Not to mention the possible partial freezing in the tank (it curdles at times the top) and there is the guaranteed crash ...

[olivcody]

ok to forget about the oil. I thought it was achievable because in all the "green" reports we say good things about it ...
otherwise, to stay on diesel I don't find it that heavy, compared to other gasoline. on the airaile site there is a comparative table and at equivalent power, the petrol engines weigh between 40 and 50 kg. or if I understood everything about gazaile2, for a petrol engine, there are parts to add that are not for a diesel (I may be wrong in understanding).

[Christophe]

Yes there is less and less difference in mass power!

Well personally if I had to fly I would be more reassured to fly in aircraft diesel than in gasoline ... even if I put a little 1LL in diesel to make it more fluid