ATOMIC 4 SPECIFICATIONS

ATOMIC 4 DATA

SPARK PLUG GAP	0.035
TIMING	POINTS START TO OPEN AT TDC #1 CYLINDER
POINT GAP
PRESTOLITE	0.018 to 0.020
DELCO	0.025
DWELL ANGLE
PRESTOLITE	38^o
DELCO	31^o to 34^o
FIRING ORDER	1-2-4-3 #1 IS ON FLYWHEEL END
INTAKE VALVE OPENS	5^o BEFORE TDC
CLOSES	50^o AFTER LDC
EXHAUST VALVE OPENS	45^o BEFORE LDC
CLOSES	10^o AFTER TDC
VALVE SEAT ANGLE	45^o
VALVE SEAT WIDTH	1/32"
VALVE STEM SIZE	0.3120 to 0.3115
VALVE STEM CLEARANCE	0.002 to 0.003
VALVE GUIDE CLEARANCE REAM TO	0.3145 to 0.3150
VALVE TAPPET CLEARANCE
INTAKE	0.008 – HOT 0.010 – COLD
EXHAUST	0.010 – HOT 0.012 – COLD
MAIN BEARING JOURNAL	1.9880 +0.0005 to –0.0000
CONNECTING ROD JOURNAL	1.5625 +0.0000 to –0.0005
MAIN BEARING CLEARANCE ON CRANKSHAFT	0.001 to 0.0025
CONNECTIONG ROD BEARING CLEARANCE	0.001 to 0.0025
CRANKSHAFT END PLAY	0.002 to 0.003 AT FRONT BEARING ONLY
CONNECTING ROD END PLAY	0.004 to 0.008
CAMSHAFT BEARING JOURNAL	1.3745 +0.0005 to –0.0000
CAMSHAFT BEARING CLEARANCE	0.0015 to 0.0025
CYLINDER BORE	2.562 to 2.553 HONE FINISH
PISTON RING SIDE CLEARANCE
COMPRESSION RING TOP	0.0015 to 0.003
COMPRESSION RING CENTER	0.001 to 0.0025
OIL RING	0.001 to 0.0025
PISTON RING GAP CLEARANCE	0.007 to 0.015
PISTON SKIRT CLEARANCE	0.0015 FEELER TO 5 POUNDS PULL
PISTON PIN SIZE	0.6880" – STANDARD
PISTON PIN CLEARANCE IN PISTON	0.001 to 0.002

TORQUE VALUES
CYLINDER HEAD NUTS	35 FT. LBS ENGINE HOT
CONNECTING ROD BOLT NUTS	33 FT. LBS.
FLYWHEEL STUD NUTS	35 FT. LBS.
MAIN BEARING NUTS	60 FT. LBS.
MANIFOLD STUD NUTS	35 FT. LBS ENGINE HOT
SPARK PLUG	30 FT. LBS.


FUEL	92 to 94 OCTANE
LUBRICATION OIL
ENGINE	SAE 30
V-DRIVE	80-90-140 GEAR LUBE – 90 HYPOID LUBE – SAE 10W-30

SUGGESTED OIL LEVELS

	INSTALLATION ANGLE	OIL AT FULL	OIL AT LOW
MODELS UJ - UJVD	0^o	5 3/4 QTS	5 QTS
	5^o	4 3/4 QTS	4 QTS
	10^o	3 1/2 QTS	2 3/4 QTS
	15^o	2 3/4 QTS	2 1/4 QTS

MODEL UJR	0^o	6 QTS	5 1/2 QTS
	5^o	5 1/4 QTS	3 3/4 QTS
	10^o	4 QTS	2 3/4 QTS
	15^o	3 1/4 QTS	2 1/2 QTS