Rebuild an SO as an HO?

[Parshal]

Originally posted by Elite1

My question is, does the 2003' SO have the same pistons as the HO?, does it have the same fuel pump components? Does it have the same injectors?, does it have the same valve seats?, does it have the same fly wheel???

The HO has different pistons than the SO. They are ported for "better cooling. " Plus, it has the j-jets to spray oil under the pistons. I think the injectors are the same but that's only because I've never seen it lists. I'm not sure about the flywheel either.

 

[DieselpowerDude]

Ok, maybe it does not say clearly, but the only thing that refers to power increase are the changes in the software. Injectors are nowhere mentioned and the piston changes refer to better oiling and cooling, not more power. This could be emissions related I read somewhere. I was only raising the fact that HO *power* seems to be made in the software, it seems, no?



Just trying to justify my CA SO I orderd

 

[Elite1]

Originally posted by DieselpowerDude

Ok, maybe it does not say clearly, but the only thing that refers to power increase are the changes in the software. Injectors are nowhere mentioned and the piston changes refer to better oiling and cooling, not more power. This could be emissions related I read somewhere. I was only raising the fact that HO *power* seems to be made in the software, it seems, no?



Just trying to justify my CA SO I orderd

Controls: new software instructing fuel pump to deliver more fuel.

Fuel System: VP44 fuel pump components changed to allow for increased fuel delivery.

Injectors: Changed to allow for increased fuel delivery.

Pistons: New design for higher 17:1 compression ratio-

Head: powdered metal valve seat inserts for improved Durability.

Flywheel: larger to match to larger diameter clutch for handling higher torque output.

 

[Rosco]

Originally posted by Elite1

Controls: new software instructing fuel pump to deliver more fuel.

Fuel System: VP44 fuel pump components changed to allow for increased fuel delivery.

Injectors: Changed to allow for increased fuel delivery.

Pistons: New design for higher 17:1 compression ratio-

Head: powdered metal valve seat inserts for improved Durability.

Flywheel: larger to match to larger diameter clutch for handling higher torque output.

I think this breakdown is for the 2nd gen high output.

 

[Rosco]

Elite1, Their is no reason why you need to justify your SO. You live in California so your hand was dealt for you in regards to engine choice. For what it's worth the SO is a stout engine and with an Edge box you are right up their with the HO boy's.



Now the flip side, even if their is no difference in the fuel delivery componets between the SO vs. HO engine, Cummins seems to think the different piston design with J-jet cooling was worth adding to the HO or else they would have saved the money and only done different software programming for the two engines.



I do feel for you because I had HO envy when I had my SO which left me with no option other than to trade up to the HO when the 48re hit the scene (actually I loved my SO but the need for an 8' bed forced me to trade it in. Therfore I was able to order the HO).





Just be glad it's not a 6. 0. :-laf :-laf

 

[Elite1]

Roscoe, True that is from 2000' when they first introduced the HO version... . but where does it say that in 2003' they did away with all of these differences?

 

[DieselpowerDude]

Elite1:

The 3rd generation has the bosch common rail injection system with does not use the vp44 so I would asume that particular writeup deals with the second gen. Oviously there is another paragraph for the 3rd gen Cummins engine:



Copied from your previous post:



What did we do to make the HO engine 305 horsepower and 555 lb-ft torque? First we beefed up components such as the pistons to handle this power level. We use gallery-cooled pistons which receive an oil spray to for cooler temperature and longer life. Then we modified software to create the greater horsepower and torque, while staying within all engine and driveline parameters. "









What according to cummins makes the power on this particular engine according to the paragraph above? Anyone know more?

 

[Elite1]

Originally posted by Rosco

Elite1, Their is no reason why you need to justify your SO. You live in California so your hand was dealt for you in regards to engine choice. For what it's worth the SO is a stout engine and with an Edge box you are right up their with the HO boy's.



Now the flip side, even if their is no difference in the fuel delivery componets between the SO vs. HO engine, Cummins seems to think the different piston design with J-jet cooling was worth adding to the HO or else they would have saved the money and only done different software programming for the two engines.



I do feel for you because I had HO envy when I had my SO which left me with no option other than to trade up to the HO when the 48re hit the scene (actually I loved my SO but the need for an 8' bed forced me to trade it in. Therfore I was able to order the HO).





Just be glad it's not a 6. 0. :-laf :-laf

Rosco, Living in CA didn't stop me... I bought my HO in AZ! Sometimes you need to have an ace up your sleeve!

 

[Carlton Bale]

Here's the deal with pistons as I understand it:



Higher Horsepower = Higher Cylinder Temperatures

Higher Cylinder Temperatures = More Expansion of Metal Pistons

More Expansion of Pistons = Greater Potential to Scuff the Piston



The HO pistons are gallery cooled, meaning that oil is sprayed directly into an internal cooling gallery, reducing piston temperatures and the potential to scuff the piston. There is a notch on the side of the gallery cooled piston, allowing the tip of the J-jet cooling nozzle to get very close to the gallery port when the piston is at bottom dead center. J-jets and gallery cooled pistons expensive are and are only included in engines with power ratings that require them.



If you add more power and no additional cooling, be prepared for bad things to happen.

 

[Rosco]

Thanks Carlton for your insider insight. It seems the extra $$$$ for a HO is money that is justified.

 

[PCline]

Carlton, I can't say that I agree with your assessment of the necessity for cooled pistons.



If cooled pistons are required because of power increase that means that a simple increase of 55 hp (difference between HO and SO) requires cooled pistons. Wouldn't you be concerned about bombing and HO by more than 55 hp then?



I offer a different understanding of the need for cooled pistons.



Emissions



Cummins couldn't meet the emissions requirements for either NOx or PM (I can't remember which, but the article in TDR issue 40 explains it) with the HO engine. Therefore by cooling the pistons they could keep the combustion chamber temperature low enough to meet the emissions requirement.



I've never known a bomber to be too concerned with emissions, so for those of you with SO engines, I say bomb away!!

 

[krabman]

Your egt gauge will tell you whats happening, and I consider cooling measures to be bigger turbo, exhaust, etc.

 

[Vaughn MacKenzie]

SO has cooled pistons too!!

The SO has cooled pistons also. ALL 24-valve engines have cooled pistons.



The difference with the 2003 HO is that is has additional cooling, the piston gallery cooling, that the 2nd gen HOs or any other 24-valve does not have.



Just wanted to make sure everyone was clear on this. IMO those who crank up their power responsibly on the SO will not have piston durability issues based on the fact the 2nd gen 24-valves have held up so well to insane BOMBing.



Vaughn

 

[jwilliams3]

Vaughn,

You are correct the Standard Output comes equipped with the piston cooling nozzles that were a mainstay of previous B engines. These were installed in the upper main bearing saddles of the block.

Pressurized oil spray would lubricate and cool the bottom of the piston and cylinder walls, rod assembly etc.



Gallery cooled pistons used on the HO engines do not have the traditional piston cooling nozzles installed in the bearing saddles, instead this area is plugged.

I think the Gallery piston cooling system has been explained in previous posts.



I agree, I haven't scuffed any pistons. I recently had a friends truck apart to install an O ringed head (470+hp engine), no scuffs on the cylinder walls.



I do think that the Gallery cooled system is superior (piston temps).

But, I wouldn't be afraid to upgrade an standard output engine.



--Justin

 

[Carlton Bale]

PCline,



You are correct, reduced cylinder temperatures are required to lower NOx. (The trade-off is a decrease in ability to burn-off particulates, so PM emissions go up. ) The ISB02 engine, on which the Dodge engine is based, uses recirculated exhaust gas to reduce peak combustion temperatures and lower NOx. This is done by adding inert (heat absorbing) exhaust gas to the power cylinder.



For all horsepower ratings 245 HP and above, the ISB02 engine uses J-jet piston cooling nozzles and it is not for emissions reduction -- EGR takes care of that. It's to increase the margin against scuffing.



In general, peak flame temperatures occur at torque peak when the engine is air-limited and not at max horsepower. The HO generates almost 100 ft-lbf of torque more than the SO, a 20% increase.



It's all about margin. I wouldn't want to pull an extremely heavy load out of death valley without proper cooling. The engines are designed to perform in harsh conditions. As you take away margin, you get closer to the edge and increase the possibility of going over. Be careful and realize that there are risks.

 

[PCline]

Carlton,



Thanks for the info, it's good to know that peak flame temperature and peak torque coincide. That should be useful when pulling hills in the summer. Just another reason to grab another gear and let the RPM's climb a little. These engines are so fun to drive down in the torque curve it's hard to convince yourself to shift sometimes.

 

[djbobo]

I wonder if anyone has (or even could for that matter) taken the computer from an HO and put in a SO powered truck to see if it really is only the software responsable for the different power output?



If its the same turbo, compression, injectors, intake, ect. why wouldn't it be?

dj

 

[Prairie Dog]

Originally posted by Carlton Bale

PCline,





For all horsepower ratings 245 HP and above, the ISB02 engine uses J-jet piston cooling nozzles and it is not for emissions reduction -- EGR takes care of that. It's to increase the margin against scuffing.

I'm confused. My engine does not have an EGR valve and as far as I know, none do. Is there some other way Cummins is introducing exhaust back into the combustion process?

 

[jwilliams3]

PrairieDog,

There is no EGR or any exhaust gas recirculated into your engine.



Delayed Exhaust Gas Recirculation is used on ISB02/ECHO Industrial engines. These are the engines with the rear gear train. For example: delivery trucks, ambulances, RV's etc.



--Justin

 

[Prairie Dog]

OK I get it now - wasn't paying attention to the "02" part of "ISB02".

Thanks!