Narrow Timing Assemblies On
                             General Motors 2.8L (173 CID) VIN W Engines

In order to squeeze the 2.8L (173 CID) V6 engine into the 1986 and later high performance Chevrolet Cavalier Z24, General Motors narrowed the timing sprockets and chain assembly to fit behind a slimmer front cover.

As of the 1987 model year, GM also changed the Celebrity to use the narrow chain assembly and cover.

The standard timing chain assembly will not fit behind this special shallow cover.  Use the following aftermarket or GM part numbers when assembling this engine:

                              GM             Aftermarket

     Chain:                   14102671       C371
     Camshaft Sprocket:       14074399       S620
     Crankshaft Sprocket:     14100571       S619

                                                                        The AERA Technical Committee

                                         Installing Aluminum Intake Manifolds

Over the past several months AERA members have reported numerous instances of intake manifold vacuum and engine coolant leaks on engines equipped with aluminum intake manifolds.   

These lightweight manifolds are easily distorted during installation and require special handling by the technician.

o    Remove gasket and oil residue from the mating surfaces of
     the manifold, cylinder head and block.  Do not use a high
     speed sander to remove old gaskets.

o    Inspect the areas surrounding the water ports for pits and
     corrosion.  Pitted areas can be repaired with 80% aluminum
     epoxy and then be remachined.

o    Check all mating surfaces for straightness and machine as
     necessary to correct for warp or other distortions.

o    On V-type engines, install the side gaskets and lay the
     manifold in position.  Check the gap between the manifold
     ends (front & back of engine) and the cylinder block. 
     Compare it to the thickness of the end seals.  In some cases
     it may be more appropriate to use a bead silicone sealer in
     place of the gaskets.

o    On V-type engines, remove the intake manifold and gaskets
     and apply a 1/8 bead of silicone sealer in the 4 corners
     where the cylinder heads meet the cylinder block.

o    Reinstall the intake manifold side gaskets and end seals and
     apply a 1/16 bead of silicone sealer in the 4 joints formed
     by the gaskets.  Do not use sealer on the gasket itself
     unless specified by the manufacturer.

o    Mount the manifold and torque the bolts to the specified
     torque following the recommended torque sequence using at
     least two steps.

o    Retorque the manifold after the engine has reached operating
     temperature.

                                                            The AERA Technical Committee

                         New Valve Stem Seal & Revised Valve Guide On
                                         Cummins L10 Diesel Engines

The Cummins Engine Company has revised the valve guide on their L10 series diesel engine.  The new valve guide can now accommodate a valve stem seal.

The revised valve guide, Part #3073512, can be used for both the intake and exhaust valves, but must be used in conjunction with the new seals (see illustration). The valve stem seals are unique and cannot be intermixed.  The intake valve stem seal is black, Part #3073509, and the exhaust valve stem seal is orange, Part #3073510.  

Each seal features a steel outer jacket and should be installed on the valve guide using Cummins service tool Part #3823946.  Installation of the seal-compatible guide requires a special valve guide driver, Cummins service tool Part #3823947.  The guide should be driven into the head until the top protrudes
1.069-1.089 above the top surface of the cylinder head.

All of these parts are available immediately and can be used to update earlier engines.  The former parts are no longer serviced. 

                                                                                The AERA Technical Committee

                                          Removal Of Drywall Sleeves

Even the most dificult dry wall sleeves such as Mack END 673, 675 and 711 can easily be removed without the use of special puller or adaptors.

Run a bead with an electric welder or a wirefeed welder down the length of each sleeve in the block.  This will cause the sleeve to shrink as it cools and the sleeve can then be puched out or tapped out very easily.

                                                                                  The AERA Technical Committee