how did 2004.5+ meet emissions w/o EGR?

[cerberusiam]

So I guess when you install a after market turbo with a less restrictive turbine housing you reduce egr to a degree. Any engine will have some exhaust gasses left in the cylinder. It's just imposible to get all exhaust gasses out. So all engines have some amount of egr.

Billy

Yes, on all counts. A less restrictive turbine housing, a different cam and you overide the hard parts portion of the design. The 3rd event will still contribute to a degree but no where near the effect.



As a practical excercise, cylinder scavenging is never 100% so you could make the case all engines have a level of EGR. It is not recognized as such if it is a function of configuration limits. When a design purposely increases and controls the effects of combusted charge on the intake mix then it loosely lumped under the EGR banner.



All semantics and what one wants to interpret. :-laf

 

[AH64ID]

So I guess when you install a after market turbo with a less restrictive turbine housing you reduce egr to a degree. Any engine will have some exhaust gasses left in the cylinder. It's just imposible to get all exhaust gasses out. So all engines have some amount of egr.

Billy

It is still more simple than that. . the 04. 5-07 have the exhaust valve close prior to TDC, the intake valve is closed so intake pressure doesn't matter.

 

[WCounts]

On mine there's overlap.

Billy

 

[AH64ID]

Of course there is some overlap, but not as much as years prior (I don't have the specs but its a minimal overlap at best, which is why psi really doesn't make too much of a difference). . but the main factor is that the exhaust valve closes before TDC (thus reducing the overlap) , creating an incylinder EGR. This action is what dirties the oil, reduces MPG's, and decreases NoX. If Cummins built the motor they wanted without the EPA dictating emissions I can guarantee there would be more valve duration on the exhaust side.

But luckily all of the EGR is based on the cam. . so change the cam and loose the EGR.

 

[WCounts]

I don't believe I'll be changing the cam in my truck unless the motor has to come out for some reason. Although there's a differance "like changing the intercooler" I haven't seen enough benefit for the trouble. I don't sled pull or plan on making much more hp than I'm now making. My truck runs great and gets good fuel economy so a little egr must not hurt too much.

Billy

 

[AH64ID]

I don't believe I'll be changing the cam in my truck unless the motor has to come out for some reason. Although there's a differance "like changing the intercooler" I haven't seen enough benefit for the trouble. I don't sled pull or plan on making much more hp than I'm now making. My truck runs great and gets good fuel economy so a little egr must not hurt too much.

Billy

The cam wont do anything for hp, well maybe 3 hp... But it makes the turbo spool sooner (from more exhaust), helps the oil stay cleaner longer (less soot loading), and the best part is increased mpgs across the board (1-2). . The MPG's are the reason to do it on a stock/stockish truck...



For me the overall plans for the truck are



Mod Stock Airbox with 4" cold air tube

GDP intake horn

New Exh manifold

Cam

40 hp injector nozzles



along with the Smarty Jr and free flow exhaust I have... This should net me the coolest, most efficient hp possible... and not to mention more power when towing. All in all it will be about 375-400 hp, nothing radical but a lot better drivability.

 

[CKelley1]

we did it for the 2 mpg increase and cleaner oil, as stated the hp increase is minimal but one nice surprise was the re shaping of the torque curve, towing it gives a higher low rpm and flatter curve, well worth the $1,500 spent

 

[pwr2tow]

Asking a question, are the cam grinds really that much different in years 03-07 with the 305/600 and 325/610 engines?

What would happen if you adjusted your exhaust valve to . 020 instead of the factory . 026 that would help exhaust gas escape faster? Then advance the timing with a box or programmer?

Don't laugh, just thinking out loud. One of the reasons I don't post much on any forum any more.

 

[steved]

Asking a question, are the cam grinds really that much different in years 03-07 with the 305/600 and 325/610 engines?



What would happen if you adjusted your exhaust valve to . 020 instead of the factory . 026 that would help exhaust gas escape faster? Then advance the timing with a box or programmer?



Don't laugh, just thinking out loud. One of the reasons I don't post much on any forum any more.

IIRC, they didn't specify the 0. 026" clearance until 2006... my 2004. 5 600CTD is 0. 020". I thought that change in clearances was more for valve seats than emissions?

 

[pwr2tow]

Your probably more than right, I really don't know, just asking questions.

 

[steved]

Your probably more than right, I really don't know, just asking questions.

Honestly, I don't know either... that's just what I remember, its been a long time since that discussion was had.

 

[Kubotaorange76]

i thought it was part of the design for the head to handle more heat... which was associated with the higher EGTs created from the in cylinder EGR in the 04. 5 and up.



I just got done swapping a helix 2 into my 07... havent taken it for a drive yet... .

 

[steved]

i thought it was part of the design for the head to handle more heat... which was associated with the higher EGTs created from the in cylinder EGR in the 04. 5 and up.

I think you are correct, but it was to help with dropped valve seats (due to the excessive heat), and not emissions.

 

[cerberusiam]

Asking a question, are the cam grinds really that much different in years 03-07 with the 305/600 and 325/610 engines?



What would happen if you adjusted your exhaust valve to . 020 instead of the factory . 026 that would help exhaust gas escape faster? Then advance the timing with a box or programmer?

Yes, the vlave timing is different between the 600 series engines and the earlier models to accomodate 50 state emissions. Vlave opening is delayed, duration changed and also overlap IIRC.



Adjusting the valves too loose will only change the total valve lift not the timing. Effectively increasing the EGR effect not decreasing it.



IIRC, the valve lash for the later models is to accomodate the stellite valves that were designed to handle more heat than the previous ones.

 

[steved]

There is a difference between the early 600 and the later 610/625... my 600 is 0. 020", which I think increased in 06???



I thought it was because of the dropped valve seats... or did the stelite valves come in during that time and I'm confused???

 

[Matt400]

One thing to consider when adjusting exhaust valves- The only time the valve has a chance to cool is when it comes in contact with the seat so leaning to the loose side ads a small safety margin because the tighter it is, the less time it spends on the seat.

 

[WCounts]

I believe the differances in cam timing and valve lash is too small to make a noticable differance. With the valve sitting on the seat more than 180* a few thousands differance in valve lash won't make any differance.

Billy