SHELBYGT NSM

General

Displacement. 4.0 liters (242 cubic inches)

Cylinder compression pressure. 120 to 150 psi.

Maximum variation between cylinders. 30 psi (from the highest reading)

Oil pressure. At idle (600 rpm) 13 psi.
Above (1600) rpm 37 to 75 psi.

Engine block

Bore diameter. 3.875 to 3.877 inches.

Taper and out of round (Maximum) 0.001 inches.

Deck (Head gasket surface) warpage limit. 0.002 inch per 6 inches.

Lifter bore diameter. 0.9055 to 0.9065 inch.

Cylinder head and valves

Head warpage limit. 0.002 inch per 6 inches.

Minimim valve margin. 1/32 inch

Valve seat angle, intake and exhaust. 44.5-degrees.

Valve face angle, intake and exhaust.
1999 and earlier. 45-degrees
2000. 46.5-degrees

Valve stem diameter. 0.0311 to 0.312 inch.

Valve stem-to-guide clearance. 0.001 to 0.003 inch

Valve spring free length. 1993-1995 1.967 inches
1996 and later 1.876 to 1.890 inches

Valve spring installed height. 1.64 inches

Valve length. Intake 4.822 to 4.837 inches.
Exhaust 4.837 to 4.852 inches.

Crankshaft and connecting rods.

Rod journal diameter. 2.0934 to 2.0955 inches.

Rod bearing oil clearance. Desired, 0.0015 to 0.002 inches
Allowable, 0.001 to 0.003 inch.

Connecting rod side clearance (endplay). 0.010 to 0.019 inch.

Main bearing journal diameter. No.1 thru 6. 2.4996 to 2.5001 inches.
No.7. 2.4980 to 2.4995 inches.

Main bearing oil clearance.
Desired. 0.002 inch
Allowable. 0.001 to 0.0025.

Crankshaft endplay (at thrust bearing). 0.0015 to 0.0065 inch

Maximum taper and out-of-round (all journals). 0.0005 inch

Piston and rings.

Piston-to-bore clearance.
1998 and earlier.
Desired. 0.0013 to 0.0015 inch.
Allowable. 0.0008 to 0.0015 inch.

Piston ring end gap
Compression rings.
1993 thru 1995. 0.010 to 0.020 inch.
1996 and later.
Top compression ring. 0.0090 to 0.0240 inch.
Second compression ring. 0.0190 to 0.0380 inch.

Oil control ring (steel rails)
1993 thru 1995. 0.010 to 0.025 inch.
1996 and later. 0.010 to 0.060 inch.

Piston ring side clearance
Compression rings.
Desired. 0.0017 inch
Allowable. 0.0017 to 0.0032 inch.

Oil control ring.
Desired. 0.003 inch.
Allowable
1993 thru 1995. 0.001 to 0.0095 inch.
1996 and later. 0.0024 to 0.0083 inch.

All information comes from the haynes manual. Chapter 2D-2. If there seems to be a typo let me know.

Hayden98XJ

That looks correct except the stock 4.0L engine only has a displacement of 242 not 258.

cruiser54

FIFY

SHELBYGT NSM

Thanks for fixing that. I wonder why the haynes manual said 258 cubic inches? Kinda makes me wonder if all the other information is off.

cruiser54

My thoughts exactly.

Hayden98XJ

Well i know the compression and bore diameter are right off the top of my head. Maybe it was just a typo.