One could use just about any plan and scale it up to whatever capacity you require.
Mate of mine built a scale Lister Diesel a few years back and it was 20cc so in comparison a 50cc would be rather huge.
Plan was his own design, but scale just the same.
Video here and I believe he listed the plan with a magizine in the UK.
Some comments below the video........
First thing that popped into my head was something more useful in a RC vehicle. That would be sweet. The 50cc size would be very useful for both airplanes and 1/5th scale trucks, buggies, truggies ect.
Hi i was hoping to run on petrol pump fuels. regular unleaded or diesel is great if you have a 2 stroke petrol plans sounds ideal. in fact a 2 stroke petrol makes more sense, thanks.The diesel engines of yesteryear were never 50cc.........perhaps 5cc maximum, normally up to around 2.5cc would have been the norm.
Think you must be confused with either 2 stroke petrol engines used these days which can be built light enough or methanol of the same type.
The latter are sometimes referred to as "diesel" although the Op did say "true diesel" which is what I showed.
At the top of the page the icon there shows what is normally referred to as a model diesel engine.
These run on a mix of kero, castor oil and ether. No spark or glow plug required.
If the Op is more clear on the requirement, someone may be able to help him out.
How many engines have you actually built by the way?
wow its cool! thanks - any plans going?Various manufacturers build a 2 stroke , CDI spark ignition with fuel pump on the carby, way down to 9cc's.
These run on pump fuel/oil mix.
Cheap and they work quite well.
I have a few in the range of sizes with the largest @52cc.
As I said earlier, diesel engines running on a mix of ether, castor oil and kero are usually maximum size of around 2.5cc.
NGH GT9 9cc Gas Engine With Rcexl CDI Ignition