White smoke, sweet smell (anti freeze) , blown head gasket. Run the car HARD and she'll probably start to overheat. Stop, and check your plugs. Find one that looks PERFECTLY clean, you've found the leak.
Now, you can try and cheap out with a can of heavy duty boiler sealer (I ran a Packard for 2 years on a boiler sealer fix) , and if that doesn't work, do a head gasket . BUT, send the head out and hav e it checked for warpage, and, if there is none, just have it shaved so it is completely level. Do the valves, seals, seats, clean up the ports while you have it apart.