Graham Bradley Restoration Information

SPECIFICATIONS:

GRAHAM-BRADLEY--503.93, 503.103:
Six cylinders, ' L' head type. Bore, 3 1/4" ; stroke, 4 3/8" . Piston displacement, 217.8 cu. in. Compression ratio, 6.15:1.· Approx. H.P.--Draw-bar, 22; Belt, 29.

TORQUE WRENCH TENSION--503.93, 503,103:
Cylinder head, 714 in. lbs. or 60 ft. lbs.

MAIN BEARINGS--503.93, 503.103:
Replaceable steel back, precision type.Not adjustable. To replace front main bearing (sleeve type): Remove radiator, hood, fan pulley, timing gear cover, all timing gears and the crank-shaft steel thrust washer, with shims. Next remove oil pan, front bearing filler block and the front main bearing cap. Pull bearing shell forward, tap crankshaft lightly with fiber mallet to jar bearing shell loose. Install new bearing, check that fillet fits over dowel pin and is tight against cylinder block. All other bearings: Rotate out of block. Clearance, .002". Endplay adjusted by shims in front of front bearing. Endplay, .004" to .006"

NOTE--Cleanliness must be observed
when units are assembled.

PISTONS--503.93, 503.103:
Aluminum alloy, cam ground. Remove from top. Assemble to rod so four vertical oil grooves on side of piston, and head of piston pin clamp screw on connecting rod are on camshaft side of engine.

LUBRICATION -- 503.93, 503.103:
Capacity, 5 qts. Summer, SAE 30 or 40; Winter, SAE 20.

OIL PRESSURE- 503.93, 503.103:
Pressure relief valve located on the valve side of the engine. Adjusted by installing spacers in back of spring. Pressure 45 lbs. at 1500 R.P.M.

OIL PUMP--503.93, 503.103:
Positive gear type.

PISTON CLEARANCE--503.93,503.103:
Measured with a .0025" feeler 1/2" wide, inserted at thrust side of piston. Pull required to withdraw back, feeler, 10 to 15 lbs.

CONNECTING ROD BEARINGS--503.93, 503.103:
Replaceable, steel back, precision type. Clearance, .002" Side clearance, .004" to .006"

PISTON PINS--503.93,503.103:
Clamped in rod. Fit in piston bosses lo hand push fit, at room temperature, Clearance; maximum, .005"