Join Date: Feb 2007
Nominated 16 Times in 67 Posts
TOTW/F/M Award(s): 28
Thanked 5,199 Times in 4,711 Posts
Many large marine engines have cylinder heads but don't require removal to do the valves or seats. The valve sits within a tube containg the springs, seat, etc.) which is inserted into the cylinder head and retained by bolts and can be removed when necessary or a suitable replacement exhange unit fitted in a matter of minutes. As these engines are slow running it can actually be done without stopping the engine - this idea stems from the days of steam.
Currently in madnoel10's garage:
Honda Civic 1.4l