ISB 235 vs. ISB 275 differences

[GDouglas]

I am curious to find out if the pistons and/or bowl shape is the same between the ISB 235 and the ISB 275 engines. I just got a deal I couldn't turn down on a set of 275 injectors and was curious if the spray patterns were identical to the stock ones, or if a different bowl shape to the piston was necessary to get optimum efficiency/burn.



Also, any further differences between the two engines would be nice to find out about.

 

[TxDieselKid]

don't you wish you could take 275, and put it to good use..?

As for all the research that I have done, the only REAL difference is the injectors, and the ECM program. Want I would really like is the 300hp firetruck engine program placed into my ECM. I would be willing to pay big bucks to do that.



I do know that the compression ratio is the same, but not sure of the head of the piston.



Andrew

 

[Bob Wagner]

get a ton of info here

http://www.dodgeram.org/support_pgs/diesel_ix.htm

 

[TxDieselKid]

you want it, Dodgeram.org has it....except for....!

Originally posted by Bob Wagner

http://www.dodgeram.org/support_pgs/diesel_ix.htm

That is a GREAT site, look at it at least once a week, but they don't say anything about THE REAL ISB... . This is the ECM program that I really want, just got to figure out how to get it. I wonder what else is different about this isb?



Andrew

 

[Don M]

The actual computer is different in the 275 engine. The piston and bowl design is the same. Compression height can vary even in identical engines, but the injector depth is the same in the 235 and 275 engines.

You can use the 275 injectors and they will spray in the correct area (bowl) you are concerned about.

Kinda weird to me not having a combustion chamber huh?





Don~

 

[LSMITH]

The ECM that Cummins uses on the ISB in all other applications ecept ours will accept standard Cummins programs. Our ECM will not, you are S. O. L. TDK. You cannot get the ISB 300 program without the ECM.

 

[TxDieselKid]

do you like breaking hearts????

Oh well, back to the drawing board...



Andrew

 

[FL70CAT]

how hard would it be to swap in a Cummins ECM??

 

[LSMITH]

TDK, no not really, but I don't mind it either



FL70CAT, first welcome aboard. The ECM retrofit has been looked at by some of the members in the past. Going off of memory the hard part would be getting the instrumentation in the Dodge to work as it is driven by the ECM. I don't think anyone really knows if the Cummins ECM can support these functions in a Dodge truck or not. There was also some talk of using the Dodge ECM and a Cummins ECM leaving the Dodge to run the instruments and letting the Cummins manage the engine in a parallel arrangement. The cost of the ECM and time investment have prevented anyone from trying it that I am aware of. I think the cost to potential customers of a conversion package would also be high enough to preclude any commercial interest. There is some more information on the boards that you can find using the search feature. Good luck and again welcome aboard.

 

[dan_gilson]

The CPL on the engine is what Cummins used to determine the parts used for a given engine. The pistons are different for the 275 as per Cummins: The difference listed was an extra compression ring to handle the increased cylinder pressues for the increased HP. There are probably a number of other difference through the engine based in increased load expectations.



Thus said, there have been a lot of post from people who have used larger injectors with varying amounts (or should I say very large) success.



You might want to search for BOMB'ing. There are several post that explain the well understood order so that you will minimize the chances of breaking things.



Bomb on...

 

[Evan A. Beck]

There's more to the non-Chrysler version of the ISB than a alot of folks know...



The 275 or 300HP program (from Cummins) will not work in the DC ECM. The program has to be custom tailored to work in the Dodge. Torque curves, RPM limits, and all kinds of other things standard in the Cummins ECM are not practical in the Dodge. I'm relatively certain that you don't want a 2700 RPM redline, right? That's why Chapple of TST was doing his own thing and changing the 275HP program.



Yeah, converting over to the 275HP ECM would be cool, but is it really a good idea? Probably not... The cost alone would be ridiculous... (raw ECM, software, datalinks, TIME) Surely you'd be into it a couple grand when its all said and done. Its just not worth it.



Why not just spend five hundred bucks and plug in an EZ? That's the logical thing to do. Add some injectors for added fun.



Double ECM's? You guys are kinda nuts... *LOL*