the 3116 is a 6.6 liter and the 3126 is a 7.2 liter. cat's engine codeing is odd...
the 3116 is 6 x 1.1L.. and the 3126 is 6 x 1.2L. that doesn't seem to work for the other engines like the 3208, 3406, 3408...???

 

I believe older Cat engines were easier to identify using the 3200,3300,3400,3500 and 3600 series designations. Some of these newer engines 3116, 3126, 3176, 3196, C7, C9, C10, C11, C12, C13, C15, C15 Acert and C16 are a little harder to identify sometimes.

 

OK, I just thought the 3116 was an older version of the same engine, kinda like the 3406's.

Sorry
Chris

 

Cat has many numbering structures...most times confusing.

There is the D342...available in the 35 ton quarry truck in the 60's or 70's

to the new 3516HD. High Displacement, Electronic injection, 4 turbos, v16 engine....16 individual heads, 4V per head....pushing a truck hauling 240 TONS of dirt on six 14 foot tall, 3 foot wide tires. I forget how many HP.....too many sometimes ;-)

Needless to say when one of them babies throws a rod, it usually creates a $200k boat anchor.

 

I know the older 3406 a & b were mechanical foot pedal throttles, I have a "c" variant and the darned computer and reostat foot feed are fouling up, is it possible to bypass and go back to a manual/mechanical foot feed throttle. I keep getting a code (55 flashes) and tired of fighting to fix the problem, would going back to the mechanical pump and accessories resolve the problem?

 

The Natural Gas version of this engine has been around for a long time now, but only has dual turbos and a water-air intercooler. They have been a pretty good engine for field gas compressor engines getting a good 40,000 hours out of the bottom end.

 

U guys must be running way behind up there EEHH!!.. hahahaha..
we run 3516LE engines to right around the 100,000 hour mark before calling it done on the bottom end. Just finished up a 3520 ECOS top end overhaul today.. Running tons ofA-3's, ULB's, 36's, and GCM-CM34's....
The Cat engine identification system is strange sometimes. Some of it has to do with the era when the engine was originally designed. The 3500 series was never an OTR design, so it had different people assigning an identification to it vs. a 3208, 3116...etc.. they were initially designed as OTR engines... Still Cat, but different departments.
Dont forget C-18, C-27, C-32, C-175....