6CTA8.3-M4-265 compared to a 480C-E

[Dennis Robb]

So it seems a lot of folks are confused about these designations, the M4-265 compared to the 480C-E. I am looking at two engines with serial numbers of 46333332 and 46332307. The Cummins Quickserve Online lists them as a 6CTA8.3-M4-265, cpl2960. According to Boatdiesel, their list of data sheet from Cummins, the 480CE is listed as a 460bhp engine with a cpl of 2960. It does not list an M4-265. This seems to be confusing several folks that I am having some discussions about. This includes two Cummins mechanics who say the M4-265 is not the infamous 480CE that spits valves when overpropped. How can I be sure what these engines are?

Topic

[Rob Schepis]

SWAC – salt water aftercooled
CPL – Critical Parts List
Not sure what the “family” relates to and what significance it would be when it comes to things that matter.

Yes, this is the same engine that needs to be propped down to the 450 curve as explained here:

https://www.sbmar.com/articles/propping-cummins-6cta-8-3-480ce-vs-430450-diamond-engine/

[Dennis Robb]

460bhp/480mhp nameplate photo

Thanks Rob. I am on board with your observations. I have attached photos of the two nameplates. They both show the 480mhp rating for a 6CTA8.3-M (SWAC) and the family as M14TA. It would appear to me that they are the same as the more common or perhaps later designation of 480C-E to reflect that 480 mhp rating versus the 460 bhp that is used on the Cummins Performance curves published on Boatdiesel. I think some of the confusion is coming from these different designations at different times. The Oct28, 2002 Cummins Performance curve data sheet M-20891 indicates the engine is a 480C-E with a CPL code of 2960 fuel system is the Bosch P7100.
I don’t really know what the significance of the CPL number and the M14TA family designations are but I “think” they point to this being the same 480C-E designated engine that is having valve seat problems when overloaded for too long. I am hoping I can get some authoritative data on this site to clarify that here. I would like to know what the CPL and M14TA designations mean. I am also not sure why the Model Name is a -M and not a -M4 and I don’t know what (SWAC) means either or whether it is pertinent to determining what this engine is relative to the valve seat issue.

Once again, there are conflicting comments coming from different Cummins mechanics about what this engine is.

1 user thanked author for this post.

Jim McMillen

[Rob Schepis]

460bhp / 480mhp

My understanding is that this is all marketing hype back when Yanmar hit the market with their “impressive outputs” so Cummins had to step it up on paper… The bhp (brakehp) was converted to a mhp (metric) and rated at a colder fuel (77F vs 104F) which gave a few extra percentage points of higher hp. Like I said, the mhp is just for brochures and show & tell….. Tony will correct me if I’m wrong or add to this..

[Dennis Robb]

Reply To: 6CTA8.3-M4-465 compared to a 480C-E

I placed a typo on my first ever post on this forum, my apologies, my question involves the difference, if any, between a 6CTA8.3 -M4-460 not a 260, and the 480CE. There seems to be some conflicting nomenclature for what may be the same engine, I am not sure so I am asking if someone here knows for sure and can produce some documents to clarify if these are two different engines or the some one.

[Dennis Robb]

Thanks Tony. I just reviewed my post and realized that I screwed up and noted the 6CTA8.3-4M-460 as a -260, not a -460, my apologies. In any case, over the years I have read your valuable tips and data listings till the cows come home but I think there is some confusion in the literature that Cummins produced as they indicate 6CTA8.3-4M-460 on the Quickserve Online data sheets but I think people as well as Boatdiesel call it the 480CE which is confusing. Am I wrong or are thes two different engines?

[Tony Athens]

TYPO

[Author]

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