rvdjr

you know how older diesels knock really loud and new ones don't? what have they done to the engines to reduce the clatter? ive been looking on the web, but cant find any hint of an answer. do you guys have any ideas?

just curious

DiezelSmoke

Gotten rid of the individual pumping chambers of the Inj pump.

rvdjr

thats interesting. i always thought that the "knock" noise came from the engine cylinder, not the injection pump. since i'm no mechanical engineer i will have faith in you reasoning!

WestTN

The single fuel injection shot has been replaced by multiple smaller shots ( up to 5) to smooth the pressure rise. That makes it much quieter.

rvdjr

now it makes sense to me. are the injecters opened electronically? i cant fathom how a IP could do that mechanically.

Bigiron

The common rail feeds fuel under high pressure to the injectors which are opened electronically.

DiezelSmoke

Cummins shoots one shot (electronicly) for the power stroke just like the old pumps did, and will give an aditional one late in the stroke only when it is in the regen mode. I keep reading on here about multiple shots and that statement is mostly false.

You would be amazed at the amount of noise the old pumps would produce. When we ran them on the test stands we wore ear protection, it was that loud.