Cat 3208 vs 3126b

[Mack Turner]

My understanding is the 3126b is what came after the 3208, but was the 3208 a better engine because it wasn’t considered disposable like the 3126? The reason I ask is I'm considering purchasing another coach with the 3208.

[Steve Huber Co-Admin]

Mack,
My understanding is that neither the 3208 or 3126 are wet sleeved. This is not (IMHO) an issue for RVs as the mileage we put on them is well under the "rebuild" point. Some truckers view both engines as "throw-away" due to the problems that can develop after installing sleeves during rebuild. An advantage to a non wet sleeved engine is that one doesn't have SCA concerns or a need to add them. The 3126 was developed based on the 3116.
Steve

[Eric Maclean]

Mach
As Steve said neither engine has wet sleeve's which can lead to rebuild problems further down the line on a high mileage road application but for a motorhome welcome will any of us put that many miles on a rig.
The big difference between the 3126 and the 3208 is the fuel system the 3208 is a mechanical injection system where as the 3126 is a HEUI ( HYDRALIC ELECTRONIC UNIT INJECTION ) fully computer controlled which means better torque and fuel mileage for A given size of the engine .
The 3208 was a very good engine in it's day and I wouldn't think twice about running one in a motorhome
Neither the 3126 or the 3208 where huge power produceing engines with the 3126 a 6 cylinder at 7.2 liters and 210 HP to 330 HP and 860 ft lbs of torque and the 3208 being a V8 at 10.4 liters and 210 HP to 260 HP with a turbo and 620 ftl bs of torque in it's max configuration.
So as you can see both engines are in the same power category but be aware the 3208 was known for is ability to burn fuel
And like many engines of its era was discontinued because of tighter emissions requirements which it couldn't comply with.

Bottom line if you don't mind feeding the fuel to it the 3208 should work just fine.

Hope this helps
Eric

[Dave Atherton]

Gentlemen, might want to touch on the Caterpillar 3126B. This 3100 series engine has proven
to be a very trouble free engine. First of all people claim this is a throwaway engine  is a
incorrect statement, where as this engine can be rebuild. The engine has steel insert sleeves
pressed into the block that can be rebuilt via machining old sleeves out and installing new steel
sleeves. It is very affordable to buy a reman engine block for the 3126B loaded with pistons and
Crankshaft. Remember there are many engines in motorhomes today that are 3126 B models
and repair parts area available. This engine is also used is off road equipment and again is a proven
Trouble free. One of the biggest problems I find with the Caterpillar 3100 series is the lack of
understanding how the engine works without a injection pump and push rods to operate the injectors.
Dave Atherton Retired Cat Mechanic