1992 jeep rebuild

Mike Pauciullo

New member
hey guys i am new to the jeep thing. i am rebuilding the engine in my 1992 2.5 wrangler tomorrow and i was wondering if there is any tricks i need to know. the engine is way down on power and it has a knock/tap. parts i bought
rear main seal
rod and crank bearings
4 new pistons with rings
8 new lifters
and of course the gaskets.

the main thing i am worried about is the wrist pins...is there any tricks to get them out easy?
this is my daily driver
 

2.5L ENGINE SPECIFICATIONS

Camshaft Hydraulic Tappet ClearanceZero Lash Bearing Clearance0.025 to 0.076 mm (0.001 to 0.003 in.) Bearing Journal Diameter No. 151.54 to 51.56 mm (2.029 to 2.030 in.) No. 251.28 to 51.31 mm (2.019 to 2.020 in.) No. 351.03 to 51.05 mm (2.009 to 2.010 in.) No. 450.78 to 50.80 mm (1.999 to 2.000 in.) Base Circle Runout0.03 mm - max. (0.001 in. - max.) Camshaft Lobe Lift Exhaust6.579 mm (0.259 in.) Intake6.477 mm (0.255 in.) Valve Lift Exhaust10.528 mm (0.4145 in.) Intake10.350 mm (0.4075 in.) Intake Valve Timing Opens15.4° BTDC Closes58° ABDC Exhaust Valve Timing Opens52.8 BBDC Closes26.2° ATDC Valve Overlap41.6° Intake Duration253.3° Exhaust Duration259.° Crankshaft End Play0.038 to 0.165 mm (0.0015 to 0.0065 in.) Main Bearing Journal Diameter63.489 to 63.502 mm (2.4996 to 2.5001 in.) Main Bearing Journal Width No. 127.58 to 27.89 mm (1.086 to 1.098 in.) Main Bearing Journal Width No. 232.28 to 32.33 mm (1.271 to 1.273 in.) Main Bearing Journal Width No. 3-4-530.02 to 30.18 mm (1.182 to 1.188 in.) Main Bearing Clearance0.03 to 0.06 mm (0.001 to 0.0025 in.) Main Bearing Clearance (Preferred)0.051 mm (0.002 in.) Connecting Rod Journal Diameter53.17 to 53.23 mm (2.0934 to 2.0955 in.) Connecting Rod Journal Width27.18 to 27.33 mm (1.070 to 1.076 in.) Out-of-Round (Max. All Journals)0.013 mm (0.0005 in.) Taper (Max. - All Journals)0.013 mm (0.0005 in.) Cylinder Block Deck Height236.73 mm (9.320 in.) Deck Clearance0.000 mm (0.000 in.) Cylinder Bore Diameter - Standard98.45 to 98.48 mm (3.8759 to 3.8775 in.) Cylinder Bore Diameter - Taper (Max.)0.025 mm (0.001 in.) Cylinder Bore Diameter - Out-of-Round (Max.)0.025 mm (0.001 in.) Tappet Bore Diameter23.000 to 23.025 mm (0.9055 to 0.9065 in.) Flatness0.03 mm per 25 mm (0.001 in. per 1 in.) TORQUE SPECIFICATIONS DESCRIPTIONTORQUE A/C Compressor Bracket-to-Engine Bolts34 N·m (25 ft. lbs.) A/C Compressor Mounting Bolts27 N·m (20 ft. lbs.) A/C Low Pressure Service Valve Nut38 N·m (28 ft. lbs.) Block Heater Nut1.8 N·m (16 in. lbs.) Camshaft Sprocket Bolt108 N·m (80 ft. lbs.) Connecting Rod Nuts45 N·m (33 ft. lbs.) Converter Plate Bolts68 N·m +60° (50 ft. lbs. +60°) Cylinder Block Drain Plugs41 N·m (30 ft. lbs.) Cylinder Head Bolts #1 - 10 & #12 - 14149 N·m (110 ft. lbs.) Bolt #11135 N·m (100 ft. lbs.) Cylinder Head Cover Bolts13 N·m (115 in. lbs.) Drive Plate-to-Torque Converter Bolts54 N·m (40 ft. lbs.) Engine Shock Damper Stud Nuts23 N·m (17 ft. lbs.) Engine Mounts - Front Support Bracket Bolts61 N·m (45 ft. lbs.) Support BracketStud Nuts46 N·m (34 ft. lbs.) Support Cushion Nuts - Right Side65 N·m (48 ft. lbs.) Support Cushion Bolts/Nuts - Left Side41 N·m (30 ft. lbs.) Support Cushion Bracket Bolts54 N·m (40 ft. lbs.) Support Cushion Bracket Stud Nuts41 N·m (30 ft. lbs.) Support Cushion Thru-Bolt65 N·m (48 ft. lbs.) Engine Mounts - Rear Crossmember-to-Sill Bolts (Automatic)41 N·m (30 ft. lbs.) Support Cushion/Crossmember Nuts22 N·m (192 in. lbs.) Support Cushion/Bracket Nuts (Manual)46 N·m (34 ft. lbs.) Transmission Support Bracket Bolt (Manual)43N·m (32 ft. lbs.) Transmission Support Bracket/ Cushion Bolt (4WD Auto)75N·m (55 ft. lbs.) Transmission Support Adaptor Bracket Bolts (2WD Auto)75N·m (55 ft. lbs.) Exhaust Manifold/Pipe Nuts27 N·m (20 ft. lbs.) Flywheel/Converter Housing Bolts38 N·m (28 ft. lbs.) Flywheel/Crankshaft Bolts143 N·m (105 ft. lbs.) Front Cover-to-Block < PISTON FITTING

BORE GAGE METHOD

  1. To correctly select the proper size piston, a cylinder bore gauge, capable of reading in 0.003 mm (.0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer.
  2. Measure the inside diameter of the cylinder bore at a point 49.5 mm (1-15/16 inches) below top of bore. Start perpendicular (across or at 90 degrees) to the axis of the crankshaft at point A and then take an additional bore reading 90 degrees to that at point B. Fig. - Bore Gauge
  3. The coated pistons will be serviced with the piston pin and connecting rod pre-assembled. The coated piston connecting rod assembly can be used to service previous built engines and MUST be replaced as complete sets. Tin coated pistons should not be used as replacements for coated pistons.
  4. The coating material is applied to the piston after the final piston machining process. Measuring the outside diameter of a coated piston will not provide accurate results. Therefore measuring the inside diameter of the cylinder bore with a dial Bore Gauge is MANDATORY.. To correctly select the proper size piston, a cylinder bore gauge capable of reading in 0.001 mm (.0001 in.) increments is required.
  5. Piston installation into the cylinder bore requires slightly more pressure than that required for non-coated pistons. The bonded coating on the piston will give the appearance of a line-to-line fit with the cylinder bore.
    PISTON SIZE CHART CYLINDER BORE SIZELETTER SIZE </B>98.438 to 98.448 mm (3.8755 to 3.8759 in.)A 98.448 to 98.458 mm (3.8759 to 3.8763 in.)B 98.458 to 98.468 mm (3.8763 to 3.8767 in.)C 98.468 to 98.478 mm (3.8767 to 3.8771 in.)D 98.478 to 98.488 mm (3.8771 to 3.8775 in.)E 98.488 to 98.498 mm (3.8775 to 3.8779 in.)F
FITTING CRANKSHAFT MAIN BEARINGS

INSPECTION

Wipe the inserts clean and inspect for abnormal wear patterns and for metal or other foreign material imbedded in the lining. Normal main bearing insert wear patterns are illustrated Main Bearing Wear Patterns
[SIZE=+1]NOTE: If any of the crankshaft journals are scored, remove the engine for crankshaft repair. [/SIZE]
Inspect the back of the inserts for fractures, scrapings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
FITTING BEARINGS (CRANKSHAFT INSTALLED)

The main bearing caps, numbered (front to rear) from 1 through 5 have an arrow to indicate the forward position. The upper main bearing inserts are grooved to provide oil channels while the lower inserts are smooth.
Each bearing insert pair is selectively fitted to its respective journal to obtain the specified operating clearance. In production, the select fit is obtained by using various-sized color-coded bearing insert pairs as listed in the Main Bearing Fitting Chart. The bearing color code appears on the edge of the insert. The size is not stamped on bearing inserts used for engine production.
The main bearing journal size (diameter) is identified by a color-coded paint mark on the adjacent cheek. The rear main journal, is identified by a color-coded paint mark on the crankshaft rear flange.
When required, upper and lower bearing inserts of different sizes may be used as a pair. A standard size insert is sometimes used in combination with a 0.025 mm (0.001 inch) undersize insert to reduce the clearance by 0.013 mm (0.0005 inch) Never use a pair of bearing inserts with greater than a 0.025 mm (0.001 inch) difference in size Bearing Insert Pairs
[SIZE=+1]NOTE: When replacing inserts, the odd size inserts must be either all on the top (in cylinder block) or all on the bottom (in main bearing cap) [/SIZE]
Once the bearings have been properly fitted, proceed to Crankshaft Main Bearing - Installation.
BEARING-TO-JOURNAL CLEARANCE (CRANKSHAFT INSTALLED)

When using Plastigage, check only one bearing clearance at a time.
Install the grooved main bearings into the cylinder block and the non-grooved bearings into the bearing caps.
Install the crankshaft into the upper bearings dry.
Place a strip of Plastigage across full width of the crankshaft journal to be checked.
Install the bearing cap and tighten the bolts to 108 N·m (80 ft. lbs.) torque.
[SIZE=+1]NOTE: DO NOT rotate the crankshaft. This will cause the Plastigage to shift, resulting in an inaccurate reading. Plastigage must not be permitted to crumble. If brittle, obtain fresh stock. [/SIZE]
Remove the bearing cap. Determine the amount of clearance by measuring the width of the compressed Plastigage with the scale on the Plastigage envelope Measuring Bearing Clearance with Plastigage Refer to Engine Specifications for the proper clearance.
Plastigage should indicate the same clearance across the entire width of the insert. If clearance varies, it may indicate a tapered journal or foreign material trapped behind the insert.
If the specified clearance is indicated and there are no abnormal wear patterns, replacement of the bearing inserts is not necessary. Remove the Plastigage from the crankshaft journal and bearing insert. Proceed to Crankshaft Main Bearing - Installation.
If the clearance exceeds specification, install a pair of 0.025 mm (0.001 inch) undersize bearing inserts and measure the clearance as described in the previous steps.
The clearance indicated with the 0.025 mm (0.001 inch) undersize insert pair installed will determine if this insert size or some other combination will provide the specified clearance. FOR EXAMPLE: If the clearance was 0.0762 mm (0.003 inch) originally, a pair of 0.0254 mm (0.001 inch) undersize inserts would reduce the clearance by 0.0254 mm (0.001 inch) The clearance would then be 0.0508 mm (0.002 inch) and within the specification. A 0.051 mm (0.002 inch) undersize bearing insert and a 0.0254 mm (0.001 inch) undersize insert would reduce the original clearance an additional 0.0127 mm (0.0005 inch) The clearance would then be 0.0381 mm (0.0015 inch)
[SIZE=+1]CAUTION: Never use a pair of inserts that differ more than one bearing size as a pair. [/SIZE]
FOR EXAMPLE: DO NOT use a standard size upper insert and a 0.051 mm (0.002 inch) undersize lower insert.
If the clearance exceeds specification using a pair of 0.051 mm (0.002 inch) undersize bearing inserts, measure crankshaft journal diameter with a micrometer. If the journal diameter is correct, the crankshaft bore in the cylinder block may be misaligned, which requires cylinder block replacement or machining to true bore.
If journals 1 through 5 diameters are less than 63.4517 mm (2.4981 inches), replace crankshaft or grind crankshaft down to accept the appropriate undersize bearing inserts.
Once the proper clearances have been obtained, proceed to Crankshaft Main Bearing - Installation.
MAIN BEARING JOURNAL DIAMETER (CRANKSHAFT REMOVED)

Remove the crankshaft from the cylinder block (refer to Cylinder Block - Disassemble)
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal with a micrometer. Measure at two locations 90° apart at each end of the journal.
The maximum allowable taper and out of round is 0.013 mm (0.0005 inch) Compare the measured diameter with the journal diameter specification (Main Bearing Fitting Chart) Select inserts required to obtain the specified bearing-to-journal clearance.
Once the proper clearances have been obtained, proceed to Crankshaft Main Bearing - Installation.
MAIN BEARING FITTING CHART

MAIN BEARING FITTING CHART
 

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