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CYL HEAD OIL GALLERY MODIFICATION |
Cylinder Head Oil Gallery Modification On
1976-85 Volvo 2.1 & 2.3L Engines
AERA members have reported a cylinder head oil gallery modification for Volvo 2.1& 2.3L engines. To enhance upper engine oiling, simply increase the diameter of the oil gallery hole to .563 (14 mm). To do so, requires the removal of the cylinder head and a drilling operation.
This engine design may allow sludge to accumulate in the oil gallery over a period of time if poor oil maintenance exists. To reduce the possibility of a seized camshaft from lack of lubrication at start-up, the following modification should be made to the cylinder head.
1. Remove cylinder head and locate the oil gallery feed hole on
the head gasket surface as shown in illustration below.
2. Obtain a .563 (14 mm) drill, and drill perpendicularly down
a distance of 1.770 (45 mm).
3. Do all other machine operations and clean thoroughly before
placing back in service.
4. Clean crankcase ventilation system and verify those
components are the manufacturer's current design.
The AERA Technical Committee |
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OFFEST CAMSHAFT KEYS |
Offset Camshaft Keys On
1997-2000 Mack E-Tech Diesel Engines
The AERA Technical Committee offers the following information regarding offset camshaft keys on 1997-2000 Mack E-Tech diesel engines. To optimize the camshaft timing on these engines, Mack has introduced an offset type camshaft key under Part # 54GC29.
This key provides cam gear offset of 1° cam and 2° engine from the straight key position. Mack has color coded the camshaft keys for easy identification for retarding or advancing the cam timing. Keys are color coded with one end of the key being painted white and the other end being painted red and is installed with the offset either to the right for cam timing retarding or to the left for cam timing advanced.
Correct camshaft key offset installation depends on the engine horsepower ratings. When an offset key is to be utilized, it must be installed with the proper color coding facing front. Shown below are the camshaft keys and their identification features. If the paint has worn off of the keys, they can be properly installed by placing the offset (as viewed from front of engine) in the direction as shown below.
Camshaft Key # Key Offset Color Code Engine HP RPM Effective 1/98 with Engine Serial Number of 8A*
54GC29 Left-Advanced RED EM7-275 @ 1750 rpm
E7-300 @ 1800 rpm
E7-300 @ 1950 rpm
E7-300 @ 1700 rpm
Effective 12/8/99 with Engine Serial Number of 9Y0870*
43AX9 Straight NONE EM7-300 @ 1750 rpm
E7-310/330
E7-330/350
E7-355/380
E7-350 @ 1800 rpm
E7-400 @ 1800 rpm
E7-454
Effective Date 6/97 with Serial Numbers E7-427-7M1305* E7-460-7M3166*
54GC29 Right Retarded WHITE E7-427
E7-460
*Prior to the offset key tie-ins given above, all E-Tech engine models used the straight key.
The AERA Technical Committee |
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CRANKSHAFT/CAMSHAFT SEAL OIL LEAKS |
Volvo Crankshaft/Camshaft Seal Oil Leaks
Possible oil leaks around the crankshaft, camshaft or other engine gaskets may be due to a clogged flame trap in the PCV system. This does not seem to happen on turbocharged models.
The plastic Y-shaped flame trap is located in the PCV apparatus and may become clogged if engine oil is infrequently changed. Low grade or inexpensive oil may also cause stoppage which allows internal crankcase pressure to build, thus forcing an oil leak. In some cases, the pressure will force the oil dipstick to pop out.
A clogged flame trap should either be cleaned or replaced, says Volvo, and normal maintenance calls for routine cleaning of the trap every 15,000 miles.
The AERA Technical Committee |
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REVISED CONNECTING ROD |
Revised Connecting Rod On
Cummins K38 & K50 Series Engines
The AERA Technical Committee offers the following information on a revised connecting rod for Cummins K38 & K50 series engines. The connecting rod was
released for production and service for all K38 and K50 engines beginning in late 1997. The rod Part #3632225 was released for service on January 9, 1999
for use in all KV engines beginning with ESN (engine serial number) 33139848. It was also placed into production on highly rated KV engines KTTA50G2 and
KTA50G3 as early as October 13, 1997 with ESN 33139138.
This revised connecting rod has been redesigned to withstand higher loads, particularly those seen on the highly rated engines. The new rod differs
visually from earlier rods in that it has increased material where the I-beam blends in with the small end. The new connecting rod is completely interchangeable with the previous design connecting rod. It can also be intermixed with older connecting rods within an engine.
The new connecting rod must be used on all KV 1500 and 1800 rpm engines when connecting rod replacements are made in service.
The new connecting rod may be used on any KV engine in the field. The new connecting rod is currently available through the parts distribution centers.
After core supplies are met, Cummins ReCon will also offer the new connecting rod and will continue to offer the current rods for lower rpm engines.
The big end housing bore of the revised rod has also been slightly modified, The new dimension is 4.2517-4.2527" (107.993-108.019 mm).
Connecting Rod Part Number Forging Number
Previous 3630024 3630023
REVISED 3632225 3632169
The AERA Technical Committee |
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REVISED CONNECTING ROD |
Revised Connecting Rods On
1988-89 Volvo 2.3L B230 Engines
AERA members have reported connecting rod failures in 1988-89 Volvo B230 engines. Rod failures include both bending and actual breakage. Because of the frequency of these failures, Volvo has redesigned the connecting rod for additional strength (See illustration). Engines manufactured as of the 1990 model year use the revised connecting rod.
The revised rod features a thicker beam and has increased in weight by 40 grams. The revised rod should only be installed in complete sets of four, Volvo Part #0271451-7 (four matched rods). Substituting a revised rod, Volvo Part #3531260-2, for the former design will cause an out-of-balance condition and possible engine failure.
The AERA Technical Committee |
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CYLINDER BLOCK & CRANKSHAFT CHANGES |
Cylinder Block & Crankshaft Change On
Volvo 1988 2.3L B230 Engines
Volvo Motors has changed the cylinder block and crankshaft on 1988 and later 2.3L B230 engines. The changes are related to the crankshaft main journal size and thrust location. Volvo also identifies 1988 and newer blocks by stamping K externally on the front timing case.
Crankshaft main journal diameters have increased in diameter to 2.4798-2.4803 (62.987-63.000 mm). The thrust bearing has been relocated to the rear main and uses a flanged type bearing. The thrust length on the crankshaft was also increased to a length of 1.398 (35.5 mm). Connecting rod journals remain unchanged at 1.9285-1.9293 (48.984-49.005 mm) in diameter.
Revising the crankshaft required the block main bearing bores be increased to 2.6378-2.6383 (67.000-67.013 mm) in diameter.
Years Main Journal Rod Journal Thrust Main Brg.
Used Diameter Diameter Location Housing
& Length Bore
----------------------------------------------------------------
1985-87 2.1648- 1.9285- 1.142 2.3228-
2.1654 1.9293 @ #3 2.3236
1988-92 2.4798- 1.9285- 1.398 2.6378-
2.4803 1.9293 @ #5 2.6383
The AERA Technical Committee |
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ROD SIDE CLEARANCE |
Crankshaft & Connecting Rod Assembly Caution For
1980-1984 2.3L AQ151 & AQ171 Volvo Marine Engines
The AERA Technical Committee offers the following information regarding a connecting rod and crankshaft assembly caution for 1980-1984 2.3L AQ151 & AQ171 marine engines. This information is most useful when engine disassembly and reassembly personnel are different people.
These engines use a crankshaft and connecting rod combination that appears to be ?not right" when the connecting rods are assembled to the crankshaft. The reason for this concern is expressed in the photo below, as it appears there is excessive rod side-play. The view shown below is normal even though it shows approximately .125" clearance on each side of the rod.
Previous service information has been reported to be unclear as to the allowable side play for connecting rods. Illustrations? showing ?normal" rod side play is in most manuals has further confused the issue.
Volvo refers to this extra rod side clearance as a ?low friction" design and they use it in several of their automotive engines as well.
The AERA Technical Committee |
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NEW TIMING CHAIN TENSIONER FOR 1996-2003 GM 4.3L ENGINES |
New Timing Chain Tensioner Assembly For
1996-2003 GM 4.3L VIN W & X Engines
The AERA Technical Committee offers the following information on a recently released timing chain tensioner assembly for 1996-2003 GM 4.3L VIN W & X engines. This kit is the result of continued rattling type noise complaints on these engines. This type of noise has been confused with detonation type noises and those possible causes should be eliminated before installing the timing chain tensioner assembly.
This noise is most prominent between 1800-2200 rpm and has not been a cause of engine damage but more of a nuisance type situation. For continued customer satisfaction, it is suggested to install the tensioner assembly any time timing chain service is considered.
When using this kit for 1996-98 engines, it is important to make sure a roller-type chain and gear set is used. The tensioner kit involves installing a new bracket and tensioner assembly that mounts over the existing timing chain cover dowel pins. The use of pin driver J46165 is helpful to drive the bracket over the dowel pins.
Figure 1. Timing Chain Tensioner Bracket Installed
NOTE: It is also important to note while installing the front cover to place a washer under the two center cover bolts that extend through the tensioner bracket. These washers are required to maintain the proper crush on the engine front cover seal.
Parts Required
Part Number Description
12458911 Chain Kit
89017257 Tensioner
10220906 Oil Pan Gasket
88893989 O-Ring and Gasket Kit
3754587 Water Pump Gasket (2 required)
89017259 Front Cover
The AERA Technical Committee |
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CAUSES FOR KNOCKING SOUNDS ON GM 3.8L ENGINES |
Causes for Knocking Sounds on
GM 3.8L (231 CID) Engines
AERA members have reported another cause for knocking sounds coming from GM 3.8L (231 CID) engines.
If an engine is experiencing knocking or clanking noises coming from the center of the engine it is important to check the emission control devices as part of the investigation. In more than one case an inoperative EGR (Exhaust Gas Recirculation) valve been the cause of a knocking noise that appeared to be
related to piston slap or excessive rod side play.
A knocking noise being caused by an inoperative EGR system can be confirmed by manually operating the EGR valve while operating the engine at 1800-2000 RPM. The noise should disappear when the valve is opened.
Most EGR valves can be operated manually be reaching behind the valve and pushing on the metal diaphragm cover. An engine operating at idle should stall when the EGR valve is opened. Use a vacuum gauge on a T fitting tapped into the vacuum line operating the EGR valve to verify operation at engine speeds above idle. Wear protective gloves whenever performing these
tests since exhaust components heat very fast.
The AERA Technical Committee |
