RokkTech Sensor - Long Term Consequences of Use

[MMead]

Long term durability was the main reason I bought my Cummins powered Dodge. Obviously the thought of saving a little diesel sounds tempting, but I'm worried about the long term affects the RokkTech Sensor might have on my engine. I'm not trying to be negative about the sensor, I am thinking about getting one myself and am just hoping someone could help educate me on the basics of timing.



1. How does advancing the timing increase power/fuel economy?



2. If the egt is lower at idle won't this allow for more unburned fuel in the cylinders and increased deposits at idle?



3. What other ill effects could the sensor have on long term durability?



4. What other benefits could the sensor have for long term durability?



Thanks for any input!

 

[RMachida]

Long term durability was the main reason I bought my Cummins powered Dodge. Obviously the thought of saving a little diesel sounds tempting, but I'm worried about the long term affects the RokkTech Sensor might have on my engine. I'm not trying to be negative about the sensor, I am thinking about getting one myself and am just hoping someone could help educate me on the basics of timing.



1. How does advancing the timing increase power/fuel economy?



2. If the egt is lower at idle won't this allow for more unburned fuel in the cylinders and increased deposits at idle?



3. What other ill effects could the sensor have on long term durability?



4. What other benefits could the sensor have for long term durability?



Thanks for any input!

I have been thinking along the same lines. I'm sure there are many more knowledgeable here than I but here are my thoughts.



Advancing the timing could allow more complete combustion which could increase power/milage. But the higher combustion temps would probably result in increased NOx emmisions. Increased HC from incomplete combustion is easy o get rid of using a cat but NOx is difficult.



I also ordered one of these last week but haven't heard anything from the vendor regarding shipping or even acknowledgement of my order.

 

[dmurdock]

Basically think of increasing the timing (2 degrees) as equivalent to removing the catalytic converter. No effect on durability, positive effect on power/efficiency, negative effect on emissions.

 

[MMead]

Any idea why advancing the timing would cause the temps to drop in the cylinders?

 

[TFucili]

At the risk of over-simplification, I think it's not so much a case of advanced timing as it is putting back the amount it was retarded to lower NOX emissions.

 

[67guzzler]

The temperature in the cylinders is not lower at all. It may or may not be different than the default timing. The EGT temps are lower by advancing the injection timing.



In general the earlier the fueling in the power stroke, the more complete the burn and higher NOx. The later the fueling in the power stroke, some burn is still occurring as the exhaust valve opens resulting in lower NOx but higher EGT's. Lower NOx emissions is one reason for the 3rd injection pulse (late) on the 2004. 5 & the 2005's.



Basically, the later the fueling in the power stroke, the higher the EGT's will be.

 

[RaymondSmith]

I have another question to add to the mix. Will the change in timing have any effect on the cat?



Thanks

 

[RMachida]

More complete combustion should make it last longer...

 

[RMalone]

I would think that advancing timeing should result in higher cylinder temps and lower egts, because the fuel should be burning in the cylinder not in the exhaust.



NOx is decreased by reducing cylinder temps, hence the reason D. C retards the timeing. Particulate matter increases when you lower cylinder temps, hence the return of the kitty.



The only disadvantage, I see, to advancing timeing is an increase in NOx emmissions, can't see why it would hurt the engine any. Of course I really don't know a whole lot and could be wrong, so take it for what it's worth!!

 

[HEMI®Dart]

Good info here on timing. See the chart about 1/2 way down.



http://www.dodgeram.org/tech/dsl/FAQ/timing.htm

 

[dmurdock]

At the risk of over-simplification, I think it's not so much a case of advanced timing as it is putting back the amount it was retarded to lower NOX emissions.

Exactly.



You simplified my simplification.

 

[RHildreth]

Good info here on timing. See the chart about 1/2 way down.



http://www.dodgeram.org/tech/dsl/FAQ/timing.htm

Thanks for the link. Some interesting info in there. Does anyone know off-hand what the stock timing is? Would be nice to know how close the Rokk-Tech got me to that around 14. 5 BTDC the link said was best.

 

[MMead]

If everyone's egt drops by 100+ degrees with the sensor, does that mean the cylinder temps are increasing by 100+ degrees? If this is the case I would assume we would need to re-think the safe egt range on our gauges.

 

[67guzzler]

Heat inside the cylinder is good. Heat in the exhaust is bad.

 

[HOBrian]

I thought #5 and #6 tend to run hot stock. Wouldn't this make them hotter??

 

[RWood]

Think of egt's as unburned fuel. By advancing the timing you are becoming more effecient at burning the fuel so less of it is going down you pipe.

 

[DHerzog]

I'm interested too

I have read a lot of threads regarding the Rokktech sensor, and I am still undecided... . this is my first diesel and I sure don't want to mess it up.



I have two concerns:



1) If timing advances increase cylinder pressure, how close to the upper limit might it get pulling a 15K RV uphill with 4 adults in the cab, a full tank of fuel, etc. , etc. ????



2) What might the effect be with the new low sulfer fuel that we are facing???



Any power increase is surely welcomed and even a slight increease in mpg is super, especially with diesel going for $3. 25 a gallon... . BUT, not at the cost of engine longevity... .

 

[Sled Dog]

I have read a lot of threads regarding the Rokktech sensor, and I am still undecided... . this is my first diesel and I sure don't want to mess it up.



I have two concerns:



1) If timing advances increase cylinder pressure, how close to the upper limit might it get pulling a 15K RV uphill with 4 adults in the cab, a full tank of fuel, etc. , etc. ????



2) What might the effect be with the new low sulfer fuel that we are facing???



Any power increase is surely welcomed and even a slight increease in mpg is super, especially with diesel going for $3. 25 a gallon... . BUT, not at the cost of engine longevity... .

Who says that there is a "Cost of Engine Longevity"?

It may actually "Increase Engine Longevity". Especially since it is working more efficiently.

 

[Buffalo]

Advancing Timing & Emmissions Testing?

I live in a state that requires emmissions testing on diesels in the major metropolitan areas. On a new truck, the tests are waived for the first five years but, after that, you must test.



I've been thinking about doing the "tone ring mod" which does the same thing as the Rocktek Sensor, I believe.



Does anyone know if with the advance of the timing, the truck will or will not pass the tests? I suppose you could turn the tone ring back or remove & replace the sensor with the stock sensor before each yearly test. I was just wondering if the mod would throw the timing off enough to cause the truck to flunk the test.



I'd appreciate your thoughts.



Joe F. (Buffalo)

 

[Mhannink]

Heat inside the cylinder is good. Heat in the exhaust is bad.

i might be wrong but isn;t the the heat in the exhaust good to spool the turbo and heat in the head bad for the pistions