| The following technical bulletins were published by AERA. |
| | SALVAGED OEM ENGINE PARTS | Salvaged O.E.M. Engine Part Caution
More new engine components are being salvaged O.E.M. than ever before. O.E.M. production lines can save a block by custom fitting, for example, an oversize rod or main bearing. By doing so, an otherwise rejected part will be restored.
It does present a problem, however, when the engine is to be rebuilt. The unsuspecting rebuilder or mechanic will discover too late, that standard parts will not work. The unfortunate thing is that the engine has to be disassembled to find the problem and additional time spent in securing the special part.
To illustrate more specifically - the following situations have een brought to our attention:
1. Integral valve guides having oversize ID with valve stems oversize to match.
2. One or more replaceable valve guides with oversize OD.
3. All main bearing bores oversize and bearings with thick walls to compensate.
4. One or more valve lifter (tappet) bores oversize. Body of tappet is oversize to
match.
5. One or more rod and main bearings undersize ID to fit undersize crankshaft
journals.
6. Cylinder bores honed slightly oversize and fitted with special high limit
service pistons.
7. Push rods of varied lengths. (Must be identified and returned to their original
position).
8. A small quantity of cylinder blocks with deck height .030 lower than specified.
A special thicker head gasket was employed to compensate.
Summary: The best preventative action is to make no assumption that parts are going to be standard. The exceptions are small in number, but they do exist and must be considered. At times the blocks will be identified when special parts are used, but the mark of a good technician is still that he makes a thorough dimensional check and knows that the parts he installs match those originally used.
The AERA Technical Committee | | FLYWHEEL RESURFACING CAUTION | Flywheel Resurfacing Caution
The AERA Technical Committee offers the following information regarding flywheel-resurfacing caution.
The clutch surface of the flywheel is a key bridge between the power generation source and the power transmission system. Problems that accompany the
flywheel into the shop fall into four major categories: Excessive wear, hard spots and metal discoloration, warping and runout. Below is a brief description of the four major categories.
1. Excessive Wear. Caused by grooves cut into the flywheel by a worn clutch
disc.
2. Hard Spots and Metal Discoloration. Caused by the slippage of the clutch
disc. The wasted energy transformed into heat causes nucleation and creation
of carbide hard spots in the flywheel surface. The heat caused by slippage
is localized in areas of the flywheel. Due to the mass of the flywheel acting as
a heat sink, localized heat of friction is drawn off rapidly which cools the hot
spots quickly and causes the to harden.
3. Warping. Caused by abnormal heating and cooling that a flywheel encounters.
This is accentuated by the fact that most of today's flywheels are made of
forged steel vs. cast iron. This forged steel, though more durable I subject to
greater warping due to its metallurgical makeup. A regular flat flywheel that
looks perfect may have .005-.010 dish.
4. Runout. May be caused by previously misaligned resurfacing methods. This
misalignment is most likely caused when the flywheel is resurfaced without
referencing the crankshaft flange.
SAE specification J618B notes that maximum runout for a flywheel surface is .0005 per inch of flywheel diameter. For instance if we had a flywheel with a
diameter of 13, take the 13 X .0005 = .0065 surface runout. Experience has shown that runout greater than .002 will most likely cause chatter and unbalance vibration. Excessive runout greater than .005 may cause severe vibration and self-destruction.
Flywheel grinders are used for resurfacing both flat and stepped (or recessed) flywheels. The flywheel machine achieves required flatness with minimum
amounts of material removed. Abrasive grinding processes will eliminate hard spots efficiently, creating a smooth and homogeneous surface. Alignment
or parallelism of the flywheel surface is maintained by referencing the crankshaft-mounting surface for the work piece. Critical centering of recessed flywheels is accomplished by using custom adapters or centering cones.
When confronted with resurfacing stepped or recessed flywheels, not only does the surfaces have to be parallel and correctly centered, but also the depth
relationship between steps must be maintained. Simply put, if .020 is removed from the lower step area, then .020 must be removed from the upper step area.
To assure that the correct dimension is to be used, measuring the clutch surface depth before and after grinding is done is recommended. Since grinding stones leave a radius on the corner of the clutch cover-mounting surface, squaring the radius to a perpendicular edge should finish the job. This will insure that the mating clutch pressure plate assembly will match up squarely when reinstalled.
The AERA Technical Committee | | EXCESSIVE OIL CONSUMPTION | Excessive Oil Consumption On
5.0L EFI Ford Engines
AERA members report excessive oil consumption on Ford 5.0L EFI engines. This condition has been reported on both existing engines as well as engines that have been recently rebuilt.
One very common source of oil consumption has been through the positive crankcase ventilation (PCV) system. As the first step, verifying that the correct parts are used and are in good working order. For most applications, the crankcase vacuum should be one to three inches of mercury (1 - 3 hg).
If the PCV system is working properly, check the rocker cover for a loose or deformed baffle. The baffle is located in the right valve cover, directly under the PCV valve and may allow oil to collect in a puddle. High vacuum will then pull the oil into the system. Secure or reform the baffle to prevent oil from
collecting under the PCV valve.
The AERA Technical Committee | | MAIN BEARING KNOCK | Front Main Bearing Knock On
Some 1975-1977 Ford, Lincoln, Mercury 7.5L (460 CID) Engines
It has been reported that some 1975-1977 Ford, Lincoln and Mercury 7.5L (460 CID) engines may have a front main bearing knock. The thump or knock may be distinctly heard inside the vehicle at half engine frequency when the engine is hot and is most noticeable between 800 and 1500 rpm.
Ford engineers recommend checking the engine timing. Following this move the vehicle outdoors, close the windows and shut off all accessories. Slowly raise engine speed to 1500 rpm in drive while depressing the brake pedal. If the front main bearing is defective, a definite recurring thump will be heard at half
crankshaft frequency.
To solve the noise problem, Ford Motor Company has recommended selective-fit standard and undersize bearings:
Upper main bearing (Std.)
Upper main bearing (.001)
Upper main bearing (.002)
Lower main bearing (Std.)
Lower main bearing (.001)
Lower main bearing (.002)
Any combination of the above main bearing halves can be used. The use of two different size halves on one journal is approved, however, the larger undersize should be installed in the upper position. A properly selected combination of bering halves should allow for a free-turning crankshaft when all bearing cap
bolts are correctly torqued to specifications.
Installing these selective-fit bearings should enable you to provide .0004 to .0015 clearance at the front main bearing. Try the .001 undersize bearing first and check the clearance with Plastigage or equivalent.
The AERA Technical Committee | | BROKEN ROCKER ARM BOLTS | Broken Rocker Arms On
Ford (Mercury) 5.8L (351 CID) Engines
Broken valve rocker arm bolts due to fulcrum to pedestal boss interference have been experienced in some Ford 5.8L (351 CID) Engines.
When encountering these trouble cases, check all remaining rocker arm bolts for breakaway torque turning the bolt clockwise, and checking all push rods for straightness. Bolts with breakaway torque under 20 ft.lbs. should be replaced using Part No. DOOZ- 6A527-A-5/16_18 x 1.38 bolt Grade 8 material.
All fulcrums in these problem engines must be reworked as follows: Grind and/or file the piloting chamfer edges as shown in the illustration, and remove all flared edges both on the side and bottom surfaces. If necessary buff or polish the sides of the fulcrum to ensure that it is free in the fulcrum channel.
To eliminate possible inaccurate torque readings caused by thread imperfections, lubricate the bolt threads and underside of the bolt head with engine oil. Assemble the rocker arm, fulcrum seat, bolt to the engine, and torque the bolts 20-25 ft.lbs. Then back the bolt out 4 full turns and retorque 20-25 ft.lbs. The rocker arm bolt torque has been revised from 17-23 ft.lbs. to 20-25ft.lbs.
To cut down on additional wear, mark the fulcrums so they can be installed in their original position and location in the rocker arms. Do not rotate the fulcrums 180°.
The AERA Technical Committee | | STEEL HEAD GASKET REPLACEMENT | Cylinder Head Gasket Replacement On
Ford (Mercury) 7.0L (428 CID)
V-8 Police Interceptor Engine
When replacing a cylinder head gasket on a 1966-69 Ford (Mercury) 7.0L (428 CID) V-8 Police Interceptor engine, use a steel head gasket. Composition type gaskets are not recommended.
It has been found that steel gaskets reduce the possibility of a cylinder head cracking in the area of the bolt holes in these engines.
It is essential that head and block surfaces be clean and checked for flatness prior to gasket replacement. An even coat of head gasket sealer should be applied to both top and bottom gasket surfaces. Be sure to check the word front stamped on the gasket and install accordingly. Torque to specifications according to proper sequence.
The AERA Technical Committee | | FUEL PUMP DIAGNOSIS ON GASOLINE ENGINES | Fuel Pump Diagnosis on
Chrysler Gasoline Engines
Operating a vehicle with a faulty fuel pump will exhibit several symptoms. Depending on the state of disrepair of the fuel pump, the vehicle may suffer from poor acceleration and other driveability complaints when increasing loads are applied. Long cranking times during a hot restart may also be evident.
While not all driveability complaints can be attributed to a defective fuel pump, it is important to determine the condition of the fuel pump before simply replacing it.
The first test is accomplished by disconnecting the inlet and outlet lines from the fuel pump. Attach a known good vacuum gauge capable of reading 0 - 25 of Hg (inches of Mercury) to the inlet fitting of the fuel pump.
Cranking the engine over with the starter motor the fuel pump should be able to achieve at least 11 of vacuum. Readings as high as 22 may be observed and are completely normal. Fuel pumps producing less than 11 of vacuum should be replaced.
Remove the vacuum gauge and attach a pressure gauge to the outlet fitting of the fuel pump. Crank the engine over again using the starter motor and observe the pressure reading of the gauge. Compare the reading to the specifications listed below:
Engine Displacement Recommended Pressure
5.7L (360 CID) 5.75 - 7.25 PSI
5.2L (318 CID) 5.75 - 7.25 PSI
3.7L (225 CID) 4.0 - 5.5 PSI
2.5L 4.5 - 6.0 PSI
2.2L 4.5 - 6.0 PSI
1.7L 4.5 - 6.0 PSI
1.6L 4.5 - 6.0 PSI
Fuel pumps not developing sufficient pressure should be replaced.
Remove the pressure gauge and reconnect all fuel lines to the pump. Start the engine to ensure that no gasoline leaks have developed.
Only through proper testing can you ensure that the fuel pump is defective before simply replacing it.
The AERA Technical Committee | | EXCESSIVE PREIGNITION ON HSC ENGINES | Excessive Pre-Ignition On
Ford 5.0L HSC Engines
AERA members have reported instances of severe pre-ignition (ping) with some Ford 5.0L (302 CID) engines using High Swirl Combustion (HSC) cylinder heads.
On the HSC cylinder head, part of the casting extends into the combustion chamber area between the intake and exhaust valve (Figure 1). This protrusion has an extremely sharp edge that can actually start to glow, causing pre-ignition of the air fuel mixture.
Ford recommends grinding the sharp point off the casting, smoothing out any sharp corners to prevent new hot spots (Figure 2). Do not remove more than necessary or compression will be lowered to a point where the vehicle will no longer idle.
The HSC cylinder head carries the casting number E6SE and can be found on some 1986 and 1989 Ford and Lincoln Mercury vehicles.
The AERA Technical Committee |
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