That is from the July 2003 GM tech link, here it is with the pictures that go with it.
A new tool EN-45680-850 has recently been released to replace cylinder bore liners in the 2.2L Ecotec four-cylinder engine (RPO L61 VIN F or D).
Background
The cylinder block of the Ecotec engine is lost-foam cast aluminum alloy, with pressed-in centrifugally-cast grey-iron cylinder bore liners.
In production, the liners are pressed into the block, then the deck of the block and liners are machined all at the same time. The production specification calls for the liners to be flush with the block, to + 0.02 mm (0.0008 in.) above deck.
The cylinder liner is beveled at the bottom end to help guide the liner into the block bore. And the top of the liner is slightly flanged, fitting into a counterbore in the block. This ensures that the liner is properly seated when it is pressed into place.
Cylinder Damage
A cylinder bore of any engine can be damaged by a broken piston ring, a loose wrist pin or clip, or piston debris caused by detonation damage. The Ecotec is susceptible to the same kinds of hazards. In the Ecotec engine, the liners are thin-wall castings, on the order of 1.5 mm (1/16-inch) thick, so overboring is not a possibility.
Up until now, if a liner became damaged, it was necessary to replace the entire engine assembly.
With the introduction of the EN-45680 L61 (L850) Cylinder Bore Liner R & I Kit, it is now possible to replace a damaged liner. This procedure can even be done with the engine remaining in the vehicle on several vehicle product lines.
Although only the damaged liner(s) must be replaced, always inspect all of the cylinders.
Detailed instructions are included with the tool kit, and are also available in SI. These are the highlights.
Liner Removal
The cylinder head must be removed, along with the piston and rod from the affected cylinder(s). Follow SI procedures.
The fixture assembly is attached above the cylinder bore with previously-used cylinder head bolts
(fig. 1).
TIP: Cylinder head bolts must not be reused.
The fixture is installed from above, with the shoe positioned flat against the bottom of the cylinder liner.
A nut on the puller is turned to pull the liner from the block.
TIP: Do not use any power tools to turn the removal tool nut, to avoid damage to the block.
FIG 1
Liner Installation
After inserting a replacement liner into the top of the cylinder bore, position the fixture above the cylinder bore and attach with the four used cylinder head bolts.
An installation assembly is used to press the liner into place
(fig. 2).
TIP: Do not use any power tools to turn the arbor screw, to avoid damage to the liner.
When the liner is installed to within 1/16-inch (1.6 mm) of the block deck face, use a torque wrench to tighten the arbor to specification. When the flange of the liner seats into the counterbore of the block, a minimal portion of the liner remains above the deck surface.
FIG 2
Liner Trimming
The kit includes debris plugs to be installed in the affected cylinder and adjacent cylinder(s).
The service liner is very similar to the ones used in production. To complete the installation, it’s necessary to machine the top of the liner to production height specification, flush with the block deck to + 0.02 mm (0.0008 in.) above deck.
It is also necessary to avoid damage to the block deck surface. This requires proper setup of the cylinder liner trim tool.
TIP: Follow the instructions exactly to set up the cutting blades of the cylinder liner trim tool, using the set gage ring supplied.
The cylinder liner trim tool is installed to the block over the affected cylinder
(fig. 3). An electric drill motor with specific power rating and rpm must be used to operate the trimmer. And compressed air operates the venturi vacuum that catches the metal shavings as the liner is trimmed.
If multiple cylinder liners are being replaced, move the cylinder liner trim tool and debris plugs from cylinder to cylinder as required.
FIG 3
Additional Information
The new tool was discussed at an Emerging Issues IDL broadcast on May 30, 2003. If you missed it, check the schedule for future re-broadcasts. Also refer to bulletin 03-06-01-018 (June 2003).
