Three-Piece Exhaust Manifold:
A three-piece, cast-iron exhaust manifold is attached to the cylinder head with twelve special alloy hardened bolts. The manifold has a square outlet flange which is bolted directly to the turbocharger turbine housing. See Figure
. Three identical exhaust manifold gaskets are used between the manifold and the cylinder head. See Figure
Typical Exhaust Manifold Mounting
Exhaust manifolds on Series 60G genset engines provide a heat shield for efficiency, see Figure
Exhaust manifolds on Series 60G automotive engines and on Series 60 keeled-cooled marine engines have an insulation wrap to contain heat. One-piece exhaust manifolds on Series 60 heat exchanger-cooled marine engines are water-cooled. See Figure
Remove the bolts that secure the exhaust manifold to the cylinder head.
Remove the three-piece manifold as an assembly or remove the one-piece manifold. Discard the three gaskets.
Cleaning of Exhaust Manifold
Clean the exhaust manifold prior to inspection as follows:
Remove any loose scale and carbon that may have accumulated on the internal walls of the manifold.
Clean the manifold exterior with a wire brush.
Inspection of the Exhaust Manifold
Inspect the exhaust manifold as follows:
Visually inspect the exhaust manifold for cracks, especially in the bolt clamp areas.
If exhaust manifold is cracked, replace with a new manifold. If it is necessary to replace individual sections of the three-piece exhaust manifold, clamp the manifold in a vise equipped with soft jaws. Use a brass drift and hammer to separate the pieces. Refer to section
If bolt holes 3, 4, 5, and 6 are 12.6-13.7 mm (0.496 - 0.539 in.) diameter, they should be drilled out to 14.7-15.7 mm (0.577-0.618 in.) before the manifold is reinstalled on the engine. This provides an extra margin of safety for thermal expansion of the manifold. See Figure
Exhaust Manifold Torque Sequence
Inspect manifold for leakage.
Check the three-piece manifold for fretting near the slip joints.
If bolt is excessively stretched, or if threads are excessively damaged, and complete manifold assembly replacement is required, three new exhaust manifold kits having center sections with reduced bolt hole boss at the #1 location
, see Figure
, are available. The new kits (23512896 - high mount, 23512897 middle mount, and 23513470 - low mount) also include bolts, studs, spacers, and special graphite-composition gaskets required for complete manifold replacement.
If bolt is excessively stretched, or if threads are excessively damaged, and if the exhaust manifold assembly is reusable, rework the center section reducing the height of the cast-in bolt hole boss, #1 location, on the center section, see Figure
, by grinding it down to 22 mm (0.87 in.). An isolating washer will be installed in this location. Glass bead inner and outer diameters of the slip joints.
Exhaust Manifolds Showing Location of Stressed Bolt and Bolt Torque Sequence
Check one-piece, water-cooled exhaust manifold for cracks or obvious signs of coolant leakage and replace, if necessary.
Inspect exhaust pipe hangers for cracks. Replace as required. Refer to OEM guidelines for proper replacement procedure.
Inspect the flexible exhaust connection to ensure there is adequate flexibility to permit engine movement without stressing the turbocharger and exhaust manifold. Refer to OEM guidelines for proper flexibility specifications.
Ensure the exhaust pipe is adequately supported. Refer to OEM guidelines to verify that the exhaust pipe is adequately supported.
Installation of Three-Piece Exhaust Manifold
Install the exhaust manifold as follows:
If disassembled, reassemble the three pieces of the exhaust manifold.
Install four exhaust manifold guide studs, J 36107
, into the cylinder head to hold the three exhaust manifold gaskets in the correct position, and facilitate manifold installation. For the modified bolt boss on the reusable center section, include one P.N. 23511667 exhaust manifold spacer under the bolts.
The bolt tightening pattern on cylinders 1, 2, and 3 reverses between middle-mount and high-mount exhaust manifolds. The exhaust gasket can be positioned either way. Ensure the guide studs and gaskets are positioned correctly for the manifold being installed.
Install the exhaust gaskets to the guide studs.
Install the assembled manifold to the guide studs.
Install eight of the bolts and spacers to the vacant holes. Finger-tighten the bolts.
Remove the four guide studs.
Install the remaining four manifold bolts and spacers to the holes from which the studs were removed.
Install seals onto exhaust manifold slip joint. Ensure the split line of the seal is positioned at the top of the manifold when the manifold is installed on engine.
When installing covers ensure the large lip of the cover is located toward the turbocharger, and the area where the lip is removed is located toward the cylinder head. Do Not Align the split lines of the cover and seal. The seal split line should be 90 degrees from the cover split line.
Install cover on seal, ensure the split line of the cover is horizontal to the floor when manifold is installed on engine. See Figure
Location of Installed Covers and Seal
Install clamp onto cover. Using large pliers compress clamp around cover and seal allowing clamp bolt to protrude. Install nut onto clamp bolt.
Do not fully tighten clamps to allow for adjustment after manifold and heat shield installation.
Position bolt so that the nut is located toward the bottom of the manifold, when the manifold is installed on the engine.See Figure
Clamp Bolt and Nut Position When Installed on Exhaust Manifold