1963 Other Peugeot Models Blue smoke

Engine Mechanical problem
1963 Other Peugeot Models 4 cyl Front Wheel Drive Manual

Hello:

I am fixing an old peugeot 404, year 1963, 4 cylinders, 1700 cc. I took apart the engine, change the following items with new ones: pistons, rings, liners, valves (all), spark plugs, carburetor, distributor, spark plug's wire, head gasket, clutch, .
After fixing the engine, putting it back with the car, after several checks of tuning, the engine ran.

Here is the problem that I can't solve: after running for about 5 to 6 minutes, the engine produces a blue smoke, smelling gasoline uncombusted. I check the bottom of spark plugs and find black ashes thicker and thicker if I leave the car running long time. So I start to clean up the plugs and the same thing happens again.

My guess is about the valves, but I am not sure. Anyway I don't have any apparatus to checks even the pressure. My only tools are screw drivers, wrenches and a galvanometer.

Could you help me out?

Thank you Sam