I know this has been asked and asked and asked since the first Common Rail hit rolled off the dealer lot, but how does the pilot injection work? Where does it hit in the stroke? (I'm assuming just as it's getting to the top of the stroke) And then where does the 3rd injection hit on the 600s? I haven't seen any thing on anyone trying to delete the 3rd injection in awhile, has everyone finally decided it would take way too much to do?

 

I believe if someone could do away with it, they would. As it would improved MPG and keep the engine oil cleaner.

It all comes down to the stupid and evil EPA. To them as long as the trucks emissions are lower, they are happy. Yet, the trucks get LOWER MPG due to the 3rd injection. It is all a GAME. Yes, it does have lower emissions BUT the truck gets worse MPG, so it burns MORE fuel.

I do NOT think it can be changed as the CAT will clog up WITHOUT the 3rd injection.

 

Is there a volume difference between the 2nd and 3rd? How far down is the 3rd event hitting? I'm trying to get technical here. (I'm a glutton for punishment)

 

I wouldnt call it dreaded...its actually a good thing. Its possable to delete it and it resulted in decreased HP and MPG. The 3rd event is a good thing and its one of the reasons that the 04.5+ get an additional 40HP from using the Smarty.

 

I said dreaded because I remember when I started on this site that there was one talking about the events every week, but at the time I didn't understand enough to pay attention to them.

 

The 3rd gen pilot injection is too small to make a significant difference in economy.

 

How does the injectors operate during the burn? Could some one do Diesel Engine 101 C (Cummins)

 

Ya know what gonna be great in 07, now you will have up to 5 injections, to keep that oxidation filter warmed up and the particulate trap from plugging up with soot.

 

I'm thinking that might be useful. That's one reason I started this thread. How does the injections work in correspondence to each other. Can having more injections be better for the power if using the same amount of fuel as a single or dual injection system? If using the same amount of fuel total for the stroke using at different times in that same stroke will it raise power, if it does then more power with the same fuel = better mileage.

 

The first event is small and starts a flame front in the cylinder so the 2nd main event doesn't cause the diesel knock and the third is just before the exhaust valve opens. by using the pilot injection(1st event) cylinder pressure doesn't spike as bad as if it was not there thereby improving the life of the HG.

 

So the 3rd happens after the piston has made it to the bottom of the stroke?

 

Since the 3rd event is part power it would have to be happening after TDC not BDC, probably in the first part. It is also a random event based on rpm, throttle position, etc, so it may vary in where it actually happens.

 

Yes, for instance, IIRC - above 1800? rpm there is no pilot injection.

I don't believe manipulating the secondary injection events will provide significant gains, although I do think their presence makes it safer to add more fuel.