engine smoke (heavy white smoke)

[MAJ]

Hi, I just want to know what can I check to make sure what is the problem? I installed this engine (used) in my Impreza 2 liter and the car started but the amount of smoke coming out is strange. I know it could be head gasket or it could be anything? can someone guide me in what to do to do all the checks.

 

[Alan Redcliffe]

Have a look in the radiator, if it looks like mayonnaise its a blown head gasket