Lighweight opposite 2-stroke engines

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jbiplane

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https://reaa.ru/attachments/izobrazhenie_2022-08-19_184922055-png.513570
izobrazhenie_2022-08-19_193804404-png.513573


New version of my 294cc 30hp Engine
 
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jbiplane

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Any more work on the LC 374cc engine?
Hi Murry. New version of 294cc engine will be delivered to customer this October. 342…400cc engines still available. I found logistic ways and deliver worldwide ignoring sanctions :) Normally I always have 1...2 assembly kits which use expensive 171...200cc Malossi cylinders. I will produce batch of 400cc air cooled opposites which can use cheap pistons, conrods and sleeves of Yamaha YFS 200+ easy to get outboard starters. It should be robust opposite ~15% "weaker" than Hirth f23 but more agile and easy to repair. At the moment it tested on UAV helicopter instead of 400cc Minary Stratos and preliminary results make me optimistic.
 

mm4440

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Hi, Malossi cylinder kits have become too expensive to consider. I would rather not source parts from China, if we have a choice, For our primary use; self launching sailplanes and light sport aircraft, 35 to 50 hp is a good target. Cost/hp and weight/hp are the main considerations. Can you give me an estimate of cost and weight of the 400cc AC twin. Please include your DFI, E starter, alternator and belt reducer. It is important, in our application to minimize engine frontal area close to prop. We are having our covid delayed 40th Western Workshop of the Experimental Soaring Association, div. of SSA, in a week. I would like to show pictures and give basic dimensions and cost estimates. Hope you and yours are well.
Murry
 

jbiplane

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that's nice, in what price range are those engines?
Cannot answer right now. Before 1Euro = 86Roubles, now 1Euro=60 Roubles (43% cheaper).
I have to wait few month when national currency become cheaper or adopt to new reality.
Probably it is correct time to upgrade company building, buy some equipment and third side parts like cylinder kits.
 

mm4440

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Hi, You mentioned YFS 200 cylinders in a recent post. LC cylinders make for a more reliable two stroke in hard aircraft application. Do the cylinder mentioned have iron sleeves or plated bores? My first motorcycle was a 1965 Yamaha 305. It had iron cylinders, if I recall correctly. The poor two stroke's pistons need all the cooling help they can get, especially when in pusher application in low speed aircraft.
 

jbiplane

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A bit hecitate what to do next (a bit bigger opposite than produced now).

Variant 1
use produced here cylinder kits 76mm bore x 61 which make 553cm volume
- liquid cooled nikasil version 67hp, expensive ~500 USD cylinder kit
- air cooled with sleeves version 50hp, 1, 5 kg heavier ~ 250USD cylinder kit

Variant 2
400cc - use Yamaha YFS pistons and sleeves + my CNC cylinders to make 43hp lc engine

Variant 3
For smaller 350cc 32hp version I can use my air cooled nikasil cylinders which weight 1,1 kg ~300 USD per one kit
and chinese copy of liquid cooled Gilera runner (declared power 19hp per cylinder ~150usd per kit)

Your opinion gentlemens? On which variant concentrate?
 
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proppastie

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multiple modular engines.......same cylinders for each...... single, twin, or four, maybe even six if opposed.....in line could be 1 or 2 or 3 or 4, 5, 6 (must come with baffles as cooling would be an issue with in-line) change case and crank for each......pined modular cranks..... components to fit each engine....only case needs to be changed....separate carb or electronic fuel injection for each cylinder.
 

mm4440

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A bit hecitate what to do next (a bit bigger opposite than produced now).

Variant 1
use produced here cylinder kits 76mm bore x 61 which make 553cm volume
- liquid cooled nikasil version 67hp, expensive ~500 USD cylinder kit
- air cooled with sleeves version 50hp, 1, 5 kg heavier ~ 250USD cylinder kit

Variant 2
400cc - use Yamaha YFS pistons and sleeves + my CNC cylinders to make 43hp lc engine

Variant 3
For smaller 350cc 32hp version I can use my air cooled nikasil cylinders which weight 1,1 kg ~300 USD per one kit
and chinese copy of liquid cooled Gilera runner (declared power 19hp per cylinder ~150usd per kit)

Your opinion gentlemens? On which variant concentrate?
Hi, pictures did not come through on my laptop? I'll poll the members at the workshop.
 

jbiplane

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pictures did not come through on my laptop
Trying post the links of variant 1 and 3
b815e875-f2cc-11e8-80e8-fcaa143051a2_90e977c9-0b51-11ea-80f6-fcaa143051a2.jpeg

- liquid cooled nikasil version 2x = 67hp, expensive ~500 USD cylinder kit
dsc01742.jpg

- air cooled with sleeves version 2x = 50hp


dc67wd3j-jpg.514330

my air cooled nikasil cylinders which weight 1,1 kg ~300 USD
1c494163d1f768ee0df49e790837d53c.jpg

chinese copy of liquid cooled Gilera runner (declared power 19hp per cylinder ~150usd per kit)
 
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