Engine Specifications

GENERAL SPECIFICATIONS

Year	Displ.		Carburetor	HP at RPM	Torque (Ft. Lbs. at RPM)	Compr. Ratio	Bore in. mm		Stroke in. mm
Year	cu. ins.	cc	Carburetor	HP at RPM	Torque (Ft. Lbs. at RPM)	Compr. Ratio	in.	mm	in.	mm
1977	75.48	1237	2-Bbl.	....	....	8.1:1	2.83	72	2.99	76

VALVES

Engine & Valve		Head Diam. In. (mm)	Face Angle	Seat Angle	Seat Width In. (mm)	Stem Diameter In. (mm)	Stem Clearance In. (mm)	Valve Lift In. (mm)
1237 cc
	Intake	1.335-1.342 (33.9-34.1)	45°	45°	.0551 (1.4)	.2591-.2594 (6.58-6.59)	.0004-.0016 (.01-.04)	.....
	Exhaust	1.177-1.185 (29.9-30.1)	45°	45°	.0551 (1.4)	.2579-.2583 (6.55-6.56)	.0020-.0031 (.05-.08)	.....

VALVE SPRINGS

Engine			Free Length In. (mm)	PRESSURE Lbs. @ In. (kg @mm)
Engine			Free Length In. (mm)	Valve Closed	Valve Open
1237 cc
	Intake
		Inner	1.654 (42.0)	19.8-24.2@1.358 (9.0-11.0034.5)	59.0-67.9@ 1.024 (26.8-30.8@26.0)
		Outer	1.573 (39.95)	16.7-20.6@ 1.437 (7.6-9.35@36.5)	72.5-83.5@ 1.094 (32.9-37.9@27.8)
	Exhaust
		Inner	1.654 (42.0)	25.8-31.5@ 1.358 (11.7-14.3@34.5)	40.8-49.6@ 1.024 (18.5-22.5@26)
		Outer	1.573 (39.95)	51.4-62.4@ 1.437 (23.3-28.3@36.5)	79.4-90.4@ 1.094 (36.0-41.0@27.8)

CAMSHAFT

Engine

Journal Dia. In. (mm)

Clearance ⁽¹⁾ In. (mm)

Lobe Lift In. (mm)

1237 cc

Intake

.....

.0020-.0035 (.05-.09)

.220 (5.6)

Exhaust

...

.0020-.0035 (.05-.09)

.216 (5.5)

⁽¹⁾	End play:0197" (.50 mm) maximum.

VALVE TIMING

Engine	INTAKE		EXHAUST
Engine	Open (BTDC)	Close (ALDC)	Open (BLDC)	Close (ATDC)
1237 cc	10°	20°	30°	10°

PISTONS, PINS, RINGS

Engine

PISTONS

PINS

RINGS

Clearance In. (mm)

Piston Fit In. (mm)

Rod Fit In. (mm)

Rings

End Gap In. (mm)

Side Clearance In. (mm)

1237 cc

.0012-.0039

.0004-.0008

⁽¹⁾.0006-.0015

No. 1

.008-.016

.0008-.0018 (.020-.045)

(.03-.10)

(.010-.022)

(.016-.039)

(.20-.40)

(.020-.045)

No. 2

.008-.016

.0008-.0018

(.20-.40)

(.20-.45)

Oil

.008-.035

.....

(.20-.90)

⁽¹⁾	Interference fit.

Main Bearing Journals				In. (mm)
Journal Dia. 1.97 (50)	A 0 to.0002 (0 to.006)	B .0002 to.0005 (.006 to.012)	c .0005 to.0007 (.012 to.018)	D .0007 to.0009 (.018 to.024)
Crankcase Counterbore Dia. 2.13 (54)	A 0 to.0002 (0 to.006)	B .0002 to.0005 (.006 to.012)	c .0005 to.0007 (.012 to.018)	D .0007 to.0009 (.018 to.024)
1 0 to -.0002 (0 to -.006)	Red -.0001 to -.0002 (-.002 to -.005)	Pink .00004 to -.0001 (.001 to -.002)	Yellow .0002 to.00004 (.004 to.001)	Green .0003 to.0002 (.007 to.004)
2 -.0002 to -.0005 (-.006 to -.012)	Pink .00004 to -.0001 (.001 to -.002)	Yellow .0002 to.00004 (.004 to.001)	Green .0003 to.0002 (.007 to.004)	Brown.0004 to.0003 (.010 to.007)
3 -.0005 to -.0007 (-.012 to-.018)	Yellow .0002 to.00004 (.004 to.001)	Green .0003 to.0002 (.007 to.004)	Brown .0004 to.0003 (.010 to.007)	Black .0005 to.0004 (.013 to.010)
4 -.0007 to-.0009 (-.018 to -.024)	Green .0003 to.0002 (.007 to.004)	Brown .0004 to.0003 (.010 to.007)	Black .0005 to.0004 (.013 to.010)	Blue .0006 to.0005 (.016 to.013)

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS

Engine	MAIN BEARINGS				CONNECTING ROD BEARINGS
Engine	Journal Dia. In. (mm)	Clearance In. (mm)	Thrust Bearing	Crankshaft End Play In. (mm)	Journal Dia. In. (mm)	Clearance In. (mm)	Side Play In. (mm)
1237 cc	1.969-1.970 (49.9-50.0)	.0009-.0017 (.024-.042)	No. 2	.004-.014 (.10-.35)	1.575-1.576 (39.9-40.0)	.0008-.0015 (.020-.038)	.0059-.0118 (.15-.30)

Connecting Rod Bearing Journals				In. (mm)
Connecting Rod Diam. 1.69 N. (43)	1 0 to.0002 (0 to.006)	2 .0002 to.0005 (.006 to.012)	3 .0005 to.0007 (.012 to.018)	4 .0007 to.0009 (.018 to.024)
Crankpin Diam. . 1.57(40)	1 0 to.0002 (0 to.006)	2 .0002 to.0005 (.006 to.012)	3 .0005 to.0007 (.012 to.018)	4 .0007 to.0009 (.018 to.024)
A 0 to -.0002 (0 to -.006)	Red -.0002 to -.0003 (-.005 to-.008)	Pink -.0001 to-.0002 (-.002 to -.005)	Yellow .00004 to-.0001 (.001 to-.002)	Green .0002 to.00004 (.004 to.001)
B -.0002 to-.0005 (-.006 to -.012)	Pink -.0001 to-.0002 (-.002 to -.005)	Yellow .00004 to -.0001 (.001 to-.002)	Green .0002 to.00004 (.004 to.001)	Brown .0003 to.0002 (.007 to.004)
C -.0005 to -.0007 (-.012 to -.018)	Yellow .00004 to -.0001 (.001 to -.002)	Green .0002 to.00004 (.004 to.001)	Brown .0003 to.0002 (.007 to.004)	Black .0004 to.0003 (.010 to.007)
D -.0007 to -.0009 (-.018 to -.024)	Green .0002 to.00004 (.004 to.001)	Brown .0003 to.0002 (.007 to.004)	Black .0004 to.0003 (.010 to.007)	Blue .0005 to.0004 (.013 to.010)

TIGHTENING SPECIFICATIONS

Application	Ft. Lbs. (mkg)
Main Bearing Cap	27-31 (3.7-4.3)
Connecting Rod Cap	18-21 (2.6-3.0)
Camshaft Support	13-16 (1.8-2.4)
Flywheel	34-38 (4.7-5.3)
Cylinder Head Bolts	37-42 (5.1-5.8)
Crankshaft Pulley	34-38 (4.7-5.3)
Timing Belt Pulley	18-25 (2.5-3.5)
Intake & Exhaust Manifolds	13-17(2.0-2.5)