So I have been wondering for some time now how our 3rd gen engines achieve EGR. I did some reading and found some generic descriptions of "in cylinder EGR". If I understood it correctly, the exhaust valve closes before TDC trapping exhaust gasses in the cylinder. Since we don't have any fancy active valve stuff on our engine I guess this is controlled by the cam. I also assume that this is the cause of lower economy and the carbon we get as well as the higher EGT we experience. Now for the questions. Is there anyone "in the know" that can confirm my assumptions? Who makes a cam that can put our engines back to a normal combustion cycle? Would any other supporting mods be required?

 

Im intersted in this also.

 

Didnt even know we had EGR so if you (or somebody) finds out how it is achieved I would be interested. Also wonder what year they started doing it.

 

07.5 6.7s was the first ones.

 

He is not talking about an external EGR. He is talking about the incylinder EGR that is accomplished with valve timing by the cam on 04.5 and up trucks. That is why they say a Helix II cam from Don M is worth it. I don't remember the details but by using the cam and the third injection event they create an EGR effect in the cylinder.


Edited: That is why the oil gets so black so quick.

 

I think one of the differences between the '04 and the '04.5 is a different cam profile, but I have not been able to confirm this. More overlap of the valves means more dilution of the intake air and, in effect, EGR.

I think "in cylinder" EGR refers to this as opposed to an EGR valve that opens to let exhaust gas flow into the intake stream.

EGR was used by Cummins even back in the '90s.

 

Oh, no wonder I didnt know I had it. Thanks for the explanation.

 

the cam change started with the 04.5 this along with retarded timing and a third injection pulse that is to far from the second one makes for dirty oil and low mileage, to get rid of the in-cylinder egr. the first thing to do is change cam, i like the pdr the best . a smarty jr with the 04.5 up beta4 software gets the temp down and timing back where it needs to be, we have not found anyone that can move the third pulse timing, the jr moves all three pulses this does help the third pulse but not enough hopefully marty can get this eventually but for now the pdr and jr gains 4+mpg

 

anyone here done the install that has a close to stock truck? 1-2 mpg???

I have a helix 2 sittin in my shop, i just got to find the time to stick it in.

 

my trucks are close to stock we are after mileage only ' i try different things on this truck if they work we add them to the other three 06's the stuff that does not goes in a big pile with the afe junk. pulling a 5th wheel the cam gained about 1.2 mpg, empty about 2. originally i was planning on a oem 03 cam i ran into a cam specialist at cummins rockey mountain that was there picking up parts and got him to give me some info i chose the pdr because the low end performance was the best the helix 2 is a little more suited for the younger generation but still way better than 04.5 up. the 6.7's cam is back near the 03 cam and thy cave up to 5 pulses and they are where they need to be if marty could get that portion of the program on our 06' we could be real happy. the 6-7 waste 20% of the fuel in regen that was directly from cummins. every 6.7 should have a H&S mod before driving off the dealer lot

 

what was the most difficult part of the cam swap?

does your oil still turn black instantly after a change?

 

carl48,

Being that Cummins has retarded timing would using a Rokktech to advance it help improve fuel mileage?

 

rokktech didnt make a mileage difference for me, smarty jr made about 2mpg over the last 6 months

 

I too am interested in a cam that does away with the in cylinder EGR.. But I want one that works well on a stock, or very close to stock engine. I have no plans to even go above the 40hp setting on my Jr... I would like a little better mpgs thou.

The 3rd injection event isn't all bad, my EGT's are great with the Smarty Jr timing. Marco tried to remove it and lost power, so its partially for emissions and partially for power.

 

im planning to start my cam swap tonight, anyone remember off hand what size wooden dowels i need to pick up, was it 3/8" or 1/2"??

What kind of coolant needs to be run in these trucks?