Thanks to all for your help,Ok,I will make the flares onto the intakes.
The injector tubes are 4mm inner diameter.Here are 2 pictures from the injectors I used.
I put them 50mm into the intakes.
Do somebody have some pictures from good injectors,so I have a idéé???I make the same for my other small pulse-jets & they are running very good.
SORRY for the dirty floor,but that's from the salt on de snowy & frozen roads here.