Roger B
Well-Known Member
That description was obviously written at an earlier stage in construction as he has found the capillary tubing for the injection pipes and hopefully the important few microns in the injection pump.
So with around 20cc per cylinder the fuel injection volume will be around 1 -2 mm3. That will work well with a 2mm injection pump plunger.
The nominal 20-1 compression ratio may be a bit low. A two stroke will only start compressing at low speeds when the ports close so the actual ratio may be less that. At higher speeds various ‘ram’ effects will come into play. How effective the blower is at low speed is also important, if the cylinder isn’t filled the required compression pressure and temperature won’t be reached. I have found at least 30 bar is needed for normal pump diesel. If an ether mixture is used the required compression will be less.
So with around 20cc per cylinder the fuel injection volume will be around 1 -2 mm3. That will work well with a 2mm injection pump plunger.
The nominal 20-1 compression ratio may be a bit low. A two stroke will only start compressing at low speeds when the ports close so the actual ratio may be less that. At higher speeds various ‘ram’ effects will come into play. How effective the blower is at low speed is also important, if the cylinder isn’t filled the required compression pressure and temperature won’t be reached. I have found at least 30 bar is needed for normal pump diesel. If an ether mixture is used the required compression will be less.
