INSERT-VALVE SEAT 2646157 - Caterpillar

3208 Truck Engines Equipped With Turbochargers (02Z)Description of Change: A new cylinder block is used on the above 3208 Engines. With the new cylinder block, a small-frame turbocharger is used on the 168 kW (225 hp) and the 157 kW (210 hp) California engines. The 186 kW (250 hp) engines still use the mid-frame turbocharger, with an adapter to fit the new cylinder block.There are two primary differences between the new and former cylinder blocks. The first is in the location of the oil supply hole for the turbocharger at the rear of the engine. The second change is in the bosses for the flywheel hous ing bolts. The two bosses nearest the center at the top of the block are removed, and the two respective bolts at the top of the flywheel housing are no longer used.
These changes permit the new turbocharger to be installed directly on the cylinder block, lower in the vee of the engine. The lower turbocharger mounting, with different exhaust connections and other changes, will permit easier engine installation in small engine compartments where clearance is at a minimum.
Adaptable To: The new 9N6357 Cylinder Block Assembly can be installed in place of the former 9N3931 Cylinder Block Group on all earlier engines. When the new block is installed, the two top bolts in the flywheel housing are not used. The former turbocharger can be installed with an adapter, or the new turobocharger can be used. The new turbocharger is not adaptable to a former cylinder block.