Turbocharging carbureted petrol 2 stroke engines

[Baluncore]

Aircraft offered better piston cooling opportunities than did static engines. Air cooling of opposed pistons can be improved over split cylinders. The split two-stroke, evolved into the opposed piston two-stroke aero-engine during the 1930s.
That then became the Napier Deltic engine in the 1950s, used in ships and trains.

some roots types (300 and 500) models are available from China. would one of them be adequate.

Those superchargers are low-cost, and have a capacity greater than required for your engine. However, the following description suggests (in its last line), that a turbocharger, rather than a blower, might be more efficient.
https://en.wikipedia.org/wiki/Junkers_Jumo_205#Design_and_development

 

[Kaseytoo]

I see the only connection with an O.P. engine is the use of a common combustion chamber to drive both pistons equally.. Both have problems keeping the exhaust piston cool, and the O.P. engine has better cylinder charge filling. The split single stops any escape of charge thru the exhaust ports.>better economy at low revs.. Charging continues after the Ex.ports have shut. Adequate fuel charging is its main problem, but solvable. . The basic 2 stroke problem is oil burning re emissions. I envisage with improved charging via better porting and other changes from S.S. traditional design (see attached), can open opportunities for total supercharging independent of the crankcase to allow full re-circulating oiling. Switching then to turbo may then be a dual possibility. (via Riedel logic). The one big advantage with a short stroke version is the large gain in con rod leverage for both rods on ignition @ TDC compared to the minute gain from an offset gudgeon pin in all ordinary engines. Cylinder location in relation to rotational direction also becomes critical to gain that extra leverage on ignition and a longer power stroke for the master piston and con rod. Other gains and limitations apply to the lesser con rod's performance because of the piston trailing effect.....by about 10 to 15 mm.

 

[tech99]

I read that supercharged 2-cycle engines were used for submarines by Germany in WW1. These were very efficient and designed to run at fixed speed. By changing a step-up gear ratio between turbine and compressor, the engine output is progressively increased. However, the pumping losses eventually reduce the power available from the engine shaft. Ultimately the turbocharger is acting as a gas turbine and the engine is acting as the combustion chamber. In this situation, more power is available from the turbo shaft than from the engine shaft.

 

[Kaseytoo]

I believe I need full supercharging independent of the crank case to start and run this engine. 2 factors involved. 1.Full internal lubrication is the intention. 2. Powered supercharging needed anyway to start it anyway, so go all the way with it. Turbo may be out of the question due to overheating of the exhaust piston. An elecctro-mechanical supercharger may be best for general use.