Cummins N14 STC, Celect, Celect Plus – Service Manual 002-004   Cylinder Head

Install new gaskets on the dowel pins in the cylinder block.

Make sure the side of the gasket marked “TOP” is up.

Install the cylinder heads in their original locations over the dowel pins.

Use clean 15W-40 oil to lubricate the cylinder head capscrews and both sides of the flat washers.

Allow the excess oil to drain from the threads.

Install 12 capscrews and washers in each cylinder head.

Complete the following steps to tighten the flange head capscrews to the specified torque values in the sequence illustrated:

Not less than one flat, and not more than two flats.

Repeat the tightening sequence to install each cylinder head.

The markings on the head of the flange head capscrews serve as an aid during installation.

After tightening the capscrew to 298 N•m [220 ft-lb], mark the cylinder head adjacent to one of the two single marks “A” or “B” on the capscrew head.

After all 12 capscrews on one head have been tightened to 298 N•m [220 ft-lb], they must be rotated in the tightening direction an additional 90 degrees. Rotate the capscrew until the mark on the cylinder head is between the next two marks joined by an arc (more than one flat and less than two flats).

When using torque plus angle, the tolerance on the 90 degree angle of rotation is one to two flats (90°± 30°). If the capscrew is rotated beyond two flats, do not loosen the capscrew.

The clamp load is still acceptable; however, rotating the capscrew beyond two flats causes additional stretch and reduces the number of reuses.

With correct tightening, the capscrew can typically be reused for the life of the engine.