Proper Fire Ring/Cylinder Sleeve-Top Combinations; General Information; Engines Built Prior To 1993 - Mack E7 Service Manual

5-101.bk Page 11 Friday, March 17, 2006 11:05 AM
PROPER FIRE RING/CYLINDER
SLEEVE-TOP COMBINATIONS

General Information

Two types of cylinder head gasket/fire ring kits
are available for E7 engines: a flat fire-ring kit and
a stepped fire-ring kit. Both kits include
instructions.
Two sleeve-top configurations are also available.
Use the correct fire ring and cylinder sleeve
combination to ensure full contact support and
improved combustion sealing. MACK
recommends using the latest cylinder sleeve
configuration when replacing all six sleeves. The
hardware selections for single cylinder sleeve
replacement and complete overhauls are
sometimes different. Either of the two correct
sleeve/fire ring configurations provide equal
combustion sealing.
Failure to use the correct fire ring can result in
insufficient sealing and damage to the engine.
200 TROUBLESHOOTING
Figure 9-1— Cylinder Sleeve/Fire Ring Configuration (Through May 1993)
To identify the fire ring/sleeve-top configuration,
look at the sleeve top outboard of the coining
bead. If the surface between the coining bead
and the sleeve OD is flat, it is an older sleeve and
requires a stepped fire ring. If the surface has a
step, use a flat fire ring. Refer to Figures 9-1
and 9-2.

Engines Built Prior to 1993

Refer to Figure 9-1.
All pre-1991 E7 engines were manufactured with
the type of cylinder sleeve shown in Figure 9-1,
and originally used flat fire rings. MACK no longer
recommends this combination. Replace the fire
rings on both heads with the stepped fire ring.
E7 engines built between January 1991 and June
1993 (before 3L serial number) require stepped
fire rings. The sleeve and piston ring sets for
these engines are different from earlier engines,
but the sleeve-top design is the same.
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