Propeller Test Citroën 2CV ultralight aircraft engine

This is my homebuilt 1970's Citroën 2CV car engine. I've stripped it down to the bare essentials, it now weighs about 36 kgs/80 pounds. The Propeller (48x17) was sent to me by the Sratt 103 designer Bernard Geffray, in order to test my engine before buying my own propeller.

The highest rpm I could achieve was 2880 rpm. I need 3000 for the ultralight aircraft, so I should adjust ignition, exhaust and carbs. The engine develops more power at higher rpm (35 at 5750 rpm) but to save weight, I'm trying to use it direct drive. If necessary, I can design a reduction unit, but we'll see.
For this test, I've fixed the engine on the back of my homemade gokart. This also allows to do dynamic tests.

Engine data:

-2 cyl. boxer
-602cc
-9:1 compression ratio

-Electronic Ignition (DGNition)
-Double Carburettors Mikuni BS34

Feel free to give advice!

Category:

Science & Technology

Tags:

• homebuilt
• citroen
• 2CV
• geit
• eend
• ugly
• duck
• engine
• motor
• moteur
• spratt
• 103
• ultralight
• ulm
• aircraft
• propeller
• hélice
• airscrew
• thrust
• kart
• vintage
• airplane
• aeronef
• avion
• freewing

[FPVandotherprojects]

Hi Renaat - just a guess, but try a little back pressure instead of those straight pipes to get that extra few hundred RPM. I am always surprised how a little back pressure makes an engine run a little better.

Buy two "supertrapp" clamp on motorcycle silencers, at least that's what I'm going to try here soon. You can really tune those types of silencers and I can send a link if you want.

Half a world away we were doing pretty much the same thing this weekend!

[iRenaatsouvagie]

@FPVandotherprojects Those pipes are actually VW Kever silencer pipes, not straight pipes. Is this good the way it is?

[leneanderthalien]

35hp with the actual configuration? (the original car engine as 29hp DIN)

This engine is not interresting with direct drive: the power and torque are to low: much better with a reductor: this allow a big propeller= much better efficiency and more power

But the Visa 652cc engine is much better (alu-nikasil cylinder=better cooling and better efficiency) :is use on some ultralights like the german motor glider ULF2

[FPVandotherprojects]

@iRenaatsouvagie Oh, that should work well for a little back pressure. Sounds like it is running real well as it is, good job!