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Topic: 8.3 vs M11 engines (Read 2632 times) previous topic - next topic

8.3 vs M11 engines

I hesitate to post this as a "versus" for it is not a contest.  To Forum members seeing this as a "public" post,  it derives from a pm from a newish member looking at coaches and he asks, what is the difference between these two engines.

I thought that I might respond in public, so to speak, that others may offer more and perhaps better information than I will include here.  And to my private correspondence member, I hope this helps.  I will reiterate what I wrote there though.....each of these is a fine engine if given proper care.  Each serves a good purpose and in FTs well designed for the service of the particular coach.  I see the 8.3 in FTs and in newer coaches of 40 ft length and three slides.

Of course some always want more power and I may be sort of like that.  Back yonder I wanted a particular GTO, not the later models.  And if we can get Mr. Dave M to join in, he can describe options to upgrade even the M11 (ISM).  I do sort of like Barry and Cindy advice though....buy the engine you want, the hp/torque you need rather than rely on an upgrade.

I think this thread will help anyone researching this,  first motorhome purchase - seeking engine advice

That said, the simple, short answer is:  The M11 is 11 liters and I think of it as 450 hp and 1450 on the torque side.  The 8.3 (liters)  went through a couple of iterations and you need to know which 8.3.  The ISC 8.3 I think of as 350 hp and 1150 torque.  As I recall, there were versions of the 8.3 in the early 1990s that may have been 300 hp and 330 hp so to the reviewer, check if it a pre 1998 8.3. They M11 (ISM) and 8.3 as I read my friends, the engines run at a bit different rpms and the mpg is different between the two (or is that just how you drive!)

Hopefully our experts in these engines will offer more help.    But to my corresponder, I would not hesitate to have either engine, they are basic, sound engines and in a FT I suspect match up well with the coach.  Others may disagree?

(oh, Happy New Year....hope your team won, if you have a team. )

Cheers to you,
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: 8.3 vs M11 engines

Reply #1 –
8.3 is a commercial B series M11 is an industrial common in over the road semis of its era.
Tom
1998 U320 40'

Re: 8.3 vs M11 engines

Reply #2 –
Quote from: TAS69 –
8.3 is a commercial B series M11 is an industrial common in over the road semis of its era.

No, the B and C are completely unrelated.

The B is a parent bore engine and is also used in Dodge PU's. The C a linered engine, as are the Cummins L and M. The C is found in a lot of trucks.

Agree, the M is larger and heavier duty.

But SERIOUSLY doubt you will ever wear out either a C or M in an RV application!
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: 8.3 vs M11 engines

Reply #3 –
I stand corrected . Had been told the 8.3 was big brother to the early 5.9's of same era. Sharing many parts including injection pumps.
Tom
1998 U320 40'
 

Re: 8.3 vs M11 engines

Reply #4 –
When I worked at Navistar we made the B & C main bearing caps for Cummins. The "B" cap is smaller than the "C" cap and has two smaller bolt holes. Not as strong.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD