Cylinder Head Specifications On
                         GM 1.6L Engines


General Motors suggests the following specifications be observed
when remanufacturing the cylinder head on 1.6L engines used in
Pontiac LeMans automobiles.

Measure the cylinder head height from the deck surface to the
rocker cover rail.  The overall height should measure no less
than 3.770 (95.7mm).  GM does not recommend the reuse of heads
that fall below this minimum specification.

The installed valve stem height should be measured using tool
#J25289.  The tool straddles the valve and stem height is
measured from the tip of the valve stem to the tool.  A minimum
clearance of .015 is recommended.   The valve tip should never
extend beyond the gauge.

AERA machine shops have determined the actual installed valve
stem height to be 1.500 for the intake and 1.625 for the
exhaust valve when measured from the valve spring seat to the tip
of the valve.

                                     The AERA Technical Committee


January 1991 - TB 727

##END##

                     Revised Main Bearing Bolt On
                     1988-93 GM 1.6L VIN 6 Engines

AERA members have reported revised main bearing bolts on 1988-93 GM
1.6L VIN 6 engines. The service manual for this Pontiac Lemans
engine indicates the use of a torque to yield main bearing bolt and
also recommends using new bolts anytime they are removed.

Recently, obtaining those new bolts revealed a difference in design
which indicated they were not a torque to yield bolt. The original
design bolt has a shank-down portion and was easily identified. The
replacement bolt, Part #11503649, has been revised and is no longer
a torque to yield bolt. This revised bolt is a straight shank bolt
and no longer requires replacement, unless it is damaged or
stretched.

The torque value for the straight shank bolt is also revised, it
should be 44-46 ft. lbs. The torque to yield bolt has a torque value
of 44-46 ft. lbs. plus an additional 90^ turn.

                                         The AERA Technical Committee


November 1996 - TB 1395

##END##

             Cylinder Block Caution On
           1988-90 GM 1.6L VIN 6 Engines 

AERA members are cautioned when obtaining replacement cylinder blocks on 1988-90 GM 1.6L VIN 6 engines. This engine is often referred to as a Daewoo or LeMans engine used only by the Pontiac division of GM. Two different cylinder blocks are used for this engine, depending on the transmission used.

The rear mounting bolt holes for the transmission bell housing are located in slightly different locations, which, may not be noticed until the engine is being 
installed into the vehicle. Only two of the five mounting bolts line up if the wrong block is used.

Identification of which block you need or have is easily achieved by viewing  the center of the block side, approximately 1 below the head gasket surface. 
If the block is intended for standard transmission use, the raised letters M/T are visible. If the block is intended for automatic transmission use, the 
raised letters A/T are visible.

                                                                               The AERA Technical Committee