Service / Parts AAPRIL, 1978

NO. SPL - 225018 - 00

Letter FILE GROUP - 19

It has been decided that all 5.1/2" bore (855-CID) Engine Models rated above the ratingof NT-335/NT-855-335 will be provided with after cooled configuration (NTA-855-400 orNTA-400). Maximum rated RPM has been reduced to 2100 RPM. The basic advantagesof an aftercooler for this type of high rated engine models are :

a: Improved B>S>F>C.

b: Peak cylinder pressure will be reduced.

c: Exhaust gas temperature reduced.

d: Increased service life of basic enginecomponents (e.g. valves, piston, rings).

Hence NT-380 model i.e. 380 @ 2300 RPM have been replaced by NTA-380 ( 380 @2100 RPM ) for all applications.

This change is applicable with immediate effect to all OEA, OEM and for replacementengines.

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