cat 3406b ?

i have a 1990 kw 3406b-ataac engine. what does the b-ataac mean?

 

It means it's a b model cat with air to air after cooler.

 

thanks for responding. what are the pros and cons to this motor ?

 

It's a good motor, fully mechanical (no computers). I put over 1 million miles on one before having to inframe it. You do need to change rod and main bearings every 250,000-300,000.

 

what does the air to air after cooler do for the engine

 

The turbo pushes the intake air through the ataac (which is in front of your radiator) which cools it down before going into the intake on your motor.