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REVISED CUMMINS SMALL CAM V8 CAMSHAFT & BEARINGS | Camshaft & Bearing Changes On
Cummins Small Cam V8 Engines
The Cummins Engine Company has introduced a revised camshaft and camshaft bearings for its V/VT-504 & V/VT-555 small cam engines.
The Cummins small cam engines carry a camshaft bearing housing bore of 2.187. The revised camshaft is no longer cross drilled and requires new camshaft bearings. The new camshaft bearings feature a wider groove and supersede all previously used bearings.
For V8 engines with 2.187 camshaft housing bores, use Cummins part #3278345 for positions 1 & 5. Use camshaft bearing part #3031037 for positions 2, 3 & 4. These new camshaft bearings may be used in conjunction with either the revised or the former design camshaft. Do not use earlier camshaft bearings with the late model camshafts.
The AERA Technical Committee | |
LOOSE VIBRATION DAMPERS ON AMC/JEEP ENGINES | Caution On Loose Crankshaft Vibration Dampers On
Some 1974-1976 American Motors V8 Engines
It has been reported that some 1974-76 American Motors V8 engines have been operating with loose crankshaft vibration dampers. If this condition is found, remove the damper and inspect its keyway, the woodruff key and the flat washer under the damper bolt.
If the flat washer is distorted or dished, it should be replaced. Both keyway and key damage can occur when an engine has been run with a loose vibration damper.
It is recommended that a worn damper, the key and the damper bolt be replaced, however, if the keyway in the damper is not worn the damper can be re-used.
When the damper is reinstalled, the crankshaft, crankshaft seal and the threads of the new damper bolt should be lightly lubricated.
Torque the damper bolt to 80-100 ft. lbs. (108.0 - 136 Nm).
The AERA Technical Committee | |
VALVE STEM SEAL SUBSTITUTION CAUTION | Valve Stem Seal Substitution Caution
Over the years there has been much discussion on the type of
valve stem seal that is best suited for a particular application.
Rather than adding fuel to the fire, this article will attempt to
shed some light on the general purpose and use of valve stem
seals on today's engines.
Valve stem seals can for the most part be categorized into two
distinct groups. The first style of valve seal grasps the valve
stem and moves up and down with the valve, shielding the valve
guide much like an umbrella, deflecting lubricating oil away from
the guide. The second style of valve seal, commonly referred to
as a positive valve seal is firmly attached to the valve guide
and acts as a squeegee on the valve stem.
Whether your shop prefers to use the deflector type or positive
type valve seal should not simply be a matter of personal
preference or dictated by stock on hand. Valve seal
manufacturers consider the engine's configuration, such as
overhead cam, in-line or V8, gas or diesel and the intended
application, passenger car, heavy duty truck or stationary power
plant when selecting a valve seal. Additional design
considerations are the PCV system employed and the amount of
operating space between valve guide, valve spring retainer and
valve spring. Follow OE guidelines or the gasket manufacturers
application catalog for the proper valve seal.
Choosing a seal that is not designed for the application can
result in not enough oil entering the valve guide leading to
galling of the valve stem or valve guide or both. On the other
hand, an improper seal may also lead to increased oil
consumption. Either misapplication will result in a comeback and
customer dissatisfaction with the work you have performed.
The AERA Technical Committee
and
Fel-Pro Incorporated
March 1988 - SPB 154
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IMPROPER ROCKER ARM APPLICATION | Improper Rocker Arm Application On
GM 2.8, 4.3, 5.0 & 5.7L Engines
Close examination of rocker arm components is necessary when rebuilding cylinder heads on Chevrolet 2.8, 4.3, 5.0 & 5.7L engines. Retaining the correct rockers for the individual engine may save future warranty claims on premature valve train wear.
Once the rocker arm components have been removed, it appears that they are similar/like components. This is where the potential problem begins. They only appear to be the same or interchangeable. Chevrolet supplies a single part number for the V8 & 4.3L rockers, and a different part number for the 2.8L
rockers. There is significant enough difference in the angle between the rocker wear face and the rocker mounting hole to warrant two different rocker arms.
Original equipment rockers are marked (see illustrations below) before installation at the factory to aid identification. Also the contact wear face of the 2.8L rocker is narrower and the pivot slot is slightly longer than the V8 & 4.3L rocker.
Aftermarket suppliers may not have any identification marks or the marks may be different than the original rockers, leaving cause for possible confusion.
Intermixing of components at the time of rebuilding may lead to premature valve train wear, and possible warranty claims.
The AERA Technical Committee | |
SURFACING CAUTIONS | Resurfacing 1978-85 Small Block Chevrolet V8 Cylinder Heads
Beginning in 1977, one of the changes Chevrolet incorporated into
its thin wall casted small block V8 cylinder heads was the angle
of the spark plug cooling port. A potential leakage problem
exists on these lightweight heads, especially when heavy or
repeated machining of the surfaces take place.
Fel-Pro Company engineers state that the walls of the cooling
port angle towards one another in pre-1977 heads (see Fig. 1).
This different angle increases the sealing area between the
combustion chamber and the spark plug cooling port whenever any
machining takes place.
Figure 2 shows the difference between the newer and older design.
The cooling port walls angle towards the combustion chamber on
the newer design. Machining the surface of this head reduces the
sealing area between the port and the combustion chamber, which
can lead to cylinder leakage.
It is recommended that AERA members do not take off more stock
than is absolutely necessary when working ont he newer design
head, and that a composition type gasket be used in place of a
steel shim gasket. A composition gasket offers more sealing area
than the protrusion bead on a steel shim gasket, making leakage
less likely to happen.
( insert Figures 1 and 2)
The AERA Technical Committee
January 1986 - SPB 128
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CRANKSHAFT SEAL LEAKS | Rear Main Crankshaft Seal Leak On
Audi 2.0L, 2.2L, 2.3L Engines
AERA member shops have reported rear main oil seal leaks on the 2.0L, 2.2L, and 2.3L engines. The engines are used in the Audi 80/90 and 100/200 cars.
To verify that the engine oil leak is coming from the rear main seal, and not from the engine's valve cover, use florescent dye in the engine oil and a black light.
Audi has released an improved crankshaft seal, part number 068-103-051G to help correct this problem. The new seal went into production after VIN # 44 LN026115 for the 100/200 models, and after VIN # 8A LA048000 for the 80/90 models.
Audi also advises using locking compound on the flywheel bolts to seal the crankcase. The torque for the non-shoulder bolt is 55 lbs. ft. The torque for the shouldered bolt is 74 lbs. ft. and Audi advises to always use new shouldered bolts.
The AERA Technical Committee | |
HYDRAULIC VALVE LIFTER NOISE | Hydraulic Valve Lifter Noise On
1988-91 Audi 2.0, 2.2 & 2.3L Engines
The AERA Technical Committee has been informed of hydraulic valve lifter noise on 1988-91 Audi 2.0, 2.2 & 2.3L engines. This noise may be heard both at engine start-up and during low engine RPM. To reduce the possibility of undesirable lifter noise, Audi now supplies a new lifter, Part #034109309AD for all 4 & 5 cylinder engines.
It is important to note that it may take as long as a week to purge all air from this new lifter after installation. At the time of this publication, AERA is unaware of an aftermarket supplier of this lifter.
The AERA Technical Committee | |
CAMSHAFT SUPPORT BUSHING INSTALLATION PROCEDURE | Camshaft Support Bushing Installation Procedures On
Cummins Small Vee Series Engines
Cummins Engine Company reports that the camshaft bushing
installation in the small vee engines is a very critical
operation, and it is essential that the correct procedures are
observed.
PREPARE THE CYLINDER BLOCK BY THOROUGHLY CLEANING AND INSPECTING:
1. Check the camshaft bores for cracks, butts, scratches and
wear.
2. Remove the four cylinder head plugs and two main oil rifle
plugs and clean these drillings and the main bearing to camshaft
bore drillings with a wire or nylon brush. It is preferred that
this be done while the cylinder block is submerged in a tank of
hot cleaning solution.
3. Remove the burrs from the lead-ion edge of the camshaft bore
with crocus cloth or similar material, giving extra attention to
the intersection of the tappet bore and the camshaft bore.
4. Thoroughly flush the block with cleaning solution after
cleaning and removing the burrs.
5. Check the bushing bores for the correct size with an inside
micrometer or a dial bore gauge.
6. On older cylinder blocks that were equipped with thin wall
camshaft bushings, the camshaft bushing bores should be machined
to 2.1865 to 2.1875 (55.537 to 55.562 mm) diameter to
accommodate the current camshaft bushing.
INSTALLING THE CAMSHAFT BUSHINGS IN THE CYLINDER BLOCK:
1. Use Service Tool, Part No. 3376037,* (small cam) and Part No.
3376143,* (big cam), to install the camshaft bushings in the
cylinder block.
2. When installing the camshaft bushings, make sure the oil
holes in the bushings are aligned with the oil holes in the
block. The oil drain hole at the front of number one camshaft
must be open. If the oil drain hole is blocked, full engine oil
pressure is applied to the end of the camshaft, and can cause
severe wear.
3. Install the camshaft bushings dry.
4. Install the interior camshaft bushings on the installation
tool, the notched end first.
INSTALL THE NUMBER THREE CAMSHAFT BUSHING FIRST FROM THE FRONT
END OF THE CYLINDER BLOCK, USING THE INSTALLATION TOOL:
1. Insert the tool (smaller diameter first) into the cylinder
block through the No. 1 camshaft bore. Continue pushing the tool
in until the small diameter of the tool is through the No. 2
bore. Install an intermediate camshaft bushing on the tool, with
notched end away from the centerbore. Continue pushing the tool
in until the small diameter of the tool goes through the
centerbore and the camshaft bushing is against the shoulder of
the large diameter of the tool and is ready to start into the
bore. Using the slide hammer adapter from Kit No. ST-1228,* or a
soft hammer, drive the camshaft bushing into the block bore.
Withdraw the tool until the small diameter of the tool clears the
No. 2 bore. Install another intermediate camshaft bushing on the
tool and push it back in until the camshaft bushing is ready to
start in the bore. Then, drive the camshaft bushing into the
block bore. Withdraw the tool from the cylinder block, install
the bushing for the No.l 1 bore on the tool. Install the tool
through the No. 1 bore and push it in until the camshaft bushing
contacts the No. 1 bore, drive camshaft bushing into the bore.
Withdraw the tool from the cylinder block, install it through No.
5 bore small diameter of the tool first. Install a camshaft
bushing on the tool, notched end away from the No. 4 bore (V8
engines). Continue pushing the tool in until the camshaft
bushing contacts No. 4 bore. Then, drive the camshaft bushing
into the bore. Withdraw the tool from the cylinder block.
Install the camshaft bushing for No. 5 bore on the tool and drive
it into the bore.
2. Check the camshaft bushing oil supply drillings from the
bottom of the cylinder block for any metal shavings after the
installation. Also, check the alignment of the oil holes of the
camshaft bushing and the cylinder block bore. (Use a 7/64 [2.78
mm] wire to ensure maximum hole opening).
CHECK THE INSTALLED CAMSHAFT BUSHINGS FOR PROPER ALIGNMENT AND
FIT:
1. The alignment of the camshaft bore should be checked after
the camshaft bushings are installed with an alignment checking
bar or by installing the camshaft. With the engine upside down
the camshaft should turn freely without binding. When the
camshaft is used to check alignment, install it using the pilot
tool, Part No. 3376324,* (small cam) and Part No. 3376325,* (big
cam) and the assistance of another person or with the block in
the vertical position. Camshaft bushings can be damaged by the
camshaft at installation or removal. Therefore, extreme care
should be used when installing or removing the camshaft.
2. If binding is encountered, Do Not Force or Drive! Remove
camshaft and check the bushings for distortion or burrs.
INSTALLATION OF THE CAMSHAFT DURING FINAL ENGINE ASSEMBLY:
1. Install the camshaft with the block upside down using the
pilot tool and the assistance of another person, or with the
block in the vertical position.
2. Prior to assembly, coat the camshaft bushing and the camshaft
bearing journals with lubriplate.
3. Slowly rotate the camshaft as it is inserted into the
cylinder block. There should be no binding as the camshaft is
inserted into the bushings. If binding is encountered, remove
camshaft and check the bushing for distortion or burrs.
RUN IN/DYNAMOMETER
1. Prelube the engine to obtain at least a minimum of 15 psi
(103.41 kPa) on the engine oil pressure gauge.
2. Crank the engine at least 15 seconds while maintaining
external oil pressure at a minimum of 15 psi (103.41 kPa).
3. Start the engine and idle at approximately 800 to 1000 rpm -
no load for 5 to 10 minutes.
4. Apply light load 25 to 50 hp until normal engine temperature
is reached.
5. Finish engine test per normal procedure.
* Tools may be ordered from Cummins Dealers or Distributors.
The AERA Technical Committee
February 1981 - SPB 74
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