Hollow pistons?

[PRINCETON_JAKE]

I was looking for some info on Mahle pistons when i noticed this on there website...

MAHLE Group | Aluminium pistons for diesel engines

Do all/most diesel pistons have hollow spots in them? Ive never noticed it on a melted piston, but ive never cut a diesel piston in half before, hmmm

 

[LReiff]

Cummins uses a very similar design on the CR ISB engines!

 

[JDGnut]

Deere is also using a simialar design but on a steel pistons, and the spray jet is aimed straight up into a hole in the bottom of the piston..

 

[LReiff]

Cummins got aimed spray jets as well.