For in depth info I would go to your Public Main Library and look for a text book on Diesels.
My old one from Trade School is by: Bill Toboldt, Diesel Fundamentals, Servic, and Repair. Ebay or Amazon will have used coies for sale.
The Fuel that retuns from your Injectors and especially from your Fuel Injection Pump help to keep things cool.
Here is some explaniation of indirect injection.
http://en.wikipedia.org/wiki/Indirect_injection