In the mean time I have verified that the problem is with
emulatedMachine=pc-i440fx-rhel7.3.0
Summarizing:
default boot ofengine VM after update to 4.1.3 is with cpuType=Broadwell
and emulatedMachine=pc-i440fx-rhel7.3.0 and the engine vm hangs at "Booting
from Hard Disk " screen
When starting with cpuType=qemu64 and emulatedMachine=pc-i440fx-rhel7.2.0
the engine comes up normally
When starting with cpuType=Broadwell
and emulatedMachine=pc-i440fx-rhel7.2.0 the engine comes up normally
When starting with cpuType=qemu64 and emulatedMachine=pc-i440fx-rhel7.3.0
the engine vm hangs at "Booting from Hard Disk " screen
Gianluca