SVX (1992) - Car SUBARU - Free user manual and instructions

USER MANUAL SVX (1992) SUBARU

M MECHANISM AND FUNCTION 2

1. General 2
2. Timing Belt 3
3. Belt Tension Adjuster 4
4. Belt Cover 5
5. Camshaft 5
6. Hydraulic Lash Adjuster 6
7. Cylinder Head 7
8. Cylinder Block 8
9. Crankshaft 9
10. Piston 9

S SPECIFICATIONS AND SERVICE DATA 10

A: SPECIFICATIONS 10
B: SERVICE DATA 11

C COMPONENT PARTS 15

1. Timing Belt 15
2. Cylinder Head and Camshaft 16
3. Cylinder Head and Valve ASSY 17
4. Cylinder Block 18
5. Crankshaft and Piston 19

W SERVICE PROCEDURE 20

1. General Precautions 20
2. Timing Belt 21
3. Camshaft 31
4. Cylinder Head 45
5. Cylinder Block 56

T TROUBLESHOOTING 76

1. Engine Trouble in General 76
2. Engine Noise 79

Simple black-and-white oval logo with five star-like shapes inside, no text or symbols present.

M MECHANISM AND FUNCTION

1. General

The Subaru 3300cc, 6-cylinders engine is made from aluminum alloy and is horizontally opposed. It is a 4-stroke cycle, water-cooled, DOHC 24-valve engine. The fuel system utilizes an MPFI (multiple fuel injection) design.

A summary of the major construction and function features is given below.

- The cylinder head is a center-plug type that utilizes pentroof combustion chambers. The four valve design is provided with two intake valves and two exhaust valves per cylinder. The intake and exhaust ports are arranged in a cross-flow design.

• The exhaust camshafts on the left and right banks are driven by a single timing belt, and a gear on the exhaust side camshaft engages with a gear on the intake side camshaft to drive it.
• A single timing belt drives two camshafts on the left and right banks and the water pump on the right bank. Belt tension is automatically adjusted to eliminate maintenance.
• The crankshaft is supported by seven bearings to provide high rigidity and strength.
• The cylinder block is made from aluminum diecast which is integrated with cast-iron cylinder liners.

Technical line drawing of an internal combustion engine (no text or labels)

Fig. 1

2. Timing Belt

A single timing belt drives two exhaust camshafts (one in the left bank and one in the right bank). The back of the belt also drives the water pump.

The timing belt teeth have a specially designed round profile to provide quiet operation. The timing belt is

composed of a strong and inflexible core wire, a wear-resistant canvas and heat-resistant rubber material.

A hydraulic belt-tension adjuster constantly maintains specified belt tension to properly drive the camshafts, as well as to provide a "maintenance-free" advantage.

Alignment mark Alignment mark (oil pump) Top mark Belt tensioner Belt tension adjuster Alignment mark Alignment mark (belt cover) Alignment mark (camshaft sprocket) Top mark Camshaft sprocket RH Timing belt Idler No. 2 Water pump pulley C2-185

Fig. 2

3. Belt Tension Adjuster

The belt tension adjuster provides a constant value of tension for the timing belt. Proper belt tension is maintained using a rod to push the tension pulley. The location of the tensioner pulley shaft center is offset in relation to the center of the pulley's outside diameter. The tensioner adjuster rod provides a rotary movement for the tensioner pulley by both tension of the spring housed in the adjuster.

(1) Action when the belt is loose

When the belt is loose, the force between the arm and rod is unbalanced so that the rod is pushed out to the left by the force of the main spring. Then, the oil pressure in the reservoir compressed by the pressure of the main spring is increased more than in the oil pressure chamber, and the oil in the reservoir pushes past the check ball to flow into the oil pressure chamber. In this way the rod is pushed to the left until the force between the arm and rod is balanced. Since the thrust F works to the arm, the pulley is rotated counterclockwise, giving tension PB to the belt.

(2) Action for balancing the belt tension

When tension PB is given to the belt and the belt tension reaches the normal level, the belt generates the reaction TB, which works as the reaction P at the pressure cone apex of the rod. Since the reaction force pushes the rod to the right, the check ball in the oil pressure chamber is closed. When the rod is pushed to the left by the oil inflow, the balance between the rod and arm is maintained to stop the arm, and the belt tension is maintained at the fixed level.

(3) Action when the belt is too tight

When the timing belt reaction force increases to such an extent that the belt will be too tight, the arm force P is larger than the rod thrust F. Consequently, the oil in the oil pressure chamber passes through the clearance between the adjuster body and rod and is returned to the reservoir in small amounts. This oil return is stopped when the rod thrust F and arm force P are balanced to maintain tension at the fixed level.

Tension arm Timing belt P F Adjuster rod Stopper Check ball Main spring Adjuster body Oil pressure chamber Oil reservoir chamber (Silicon oil) Oil seal Piston Compression spring PB TB

C2-186

Fig. 3

4. Belt Cover

The belt cover is made of synthetic resin molding which is lightweight and heat resistant. It has a totally enclosed design that utilizes rubber packing at the mating surface of the cylinder block. This eliminates the chance of dust and water from entering the interior.

A floating design is utilized by placing rubber mounting between the cylinder block and belt cover to prevent the transmission of noise and vibration.

The front belt cover has a graduated line for ignition-timing confirmation.

5. Camshaft

The DOHC engine uses four camshafts in all; intake and exhaust camshafts on the RH bank and intake and exhaust camshafts on the LH bank.

Each camshaft has a gear which allows the exhaust camshaft to drive the intake camshaft. The intake camshaft also has a sub gear for eliminating gear backlash, thereby reducing gear noise.

The cam nose part is finished with "chill" treatment to increase wear resistance and anti-scuffing properties. Each camshaft is supported by four journals with three camshaft caps and a front camshaft cap. Each camshaft flange is supported by a groove provided in the cylinder head to receive thrust force.

Left hand intake camshaft Left hand exhaust camshaft Right hand intake camshaft Right hand exhaust camshaft Front camshaft cap LH Sub gear (Non-backlash gear) Portion affected by thrust force Driven gear Oil passage Hexagonal portion for wrench Journal Journal Journal Cylinder No. Intake camshaft cap Cylinder No. Cashflow No. Snap ring Drive gear Oil passage Hexagonal portion for wrench Journal Journal Journal Cylinder No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadway No. Roadward Bottom Left Hand Left Hand Left Hand Exhaust Left Hand Exhaust Right Hand Intake Right Hand Intake Right Hand Exhaust Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No. Cylinder No.

Fig. 4

6. Hydraulic Lash Adjuster

The hydraulic lash adjuster is located between the camshaft and valve stem. The top surface of the hydraulic lash adjuster is always in contact with the cam face. The cam directly pushes the lash adjuster to open or close the valve.

The engine oil flows through the cylinder head and goes into the lash adjuster so as to always maintain zero valve clearance.

1) Action when the valve starts to lift

When the cam begins to push the lash adjuster, the bucket and plunger are pushed down. At the same time, the body is pushed up by the reaction from the valve stem. This causes the high pressure chamber to compress, increasing the oil pressure in the high pressure chamber.

2) Action while the valve is lifted

As long as the cam is pushed by the lash adjuster, the oil pressure in the high pressure chamber is held high. The oil in the high pressure chamber leaks through a very small clearance between the plunger and body. Since the high pressure chamber is compressed in a very short time, almost no change occurs in the oil quantity inside the high pressure chamber. Accordingly, the bucket, plunger and adjuster body work as an integral unit to push down the valve stem to open the valve. The passage for supplying oil from the cylinder head to the lash adjuster is closed during this period, and no oil flows into the lash adjuster.

3) Action when the valve stops lifting

When the cam completes its lash adjuster pressing stroke, the passage for supplying oil from the cylinder head to the lash adjuster opens, allowing oil to flow from the cylinder head into reservoir II of the lash adjuster. Since the pressure in the high pressure chamber is lower than the pressure in reservoir II, the check ball is pushed down by the oil pressure in reservoir II. Accordingly, oil flows into the pressure chamber until the oil pressure becomes equal between the high pressure chamber and reservoir II. Under the action of this oil pressure, the body is pressed against the valve stem and the bucket against the camshaft.

Overflow recess Reservoir II Bucket Plunger Body Oil feed hole Retainer ring Check ball High pressure chamber Check ball spring Reservoir I Sleeve Ball cage Plunger spring

2)

Load

1)

Pressure in chamber is increased

3)

Expanded

C2-188

Fig. 5

7. Cylinder Head

Combustion chambers in the cylinder head are compact, center plug, pentroof types which feature a wide "squish" area for increased combustion efficiency.

Four valves (two intake and two exhaust), which are arranged in a cross-flow design, are used per cylinder. The cylinder head gasket is made from carbon material (not asbestos). Its core is metal provided with metal hooks to increase resistance to both heat and wear.

The inner side of grommets used in the cylinder bore are reinforced with wire to withstand both high combustion pressure and temperature.

Intake valve Intake port Squish area Combustion chamber Exhaust valve Exhaust port

C2-189

Fig. 6

8. Cylinder Block

The cylinder block is made from aluminum diecast. The cylinder perimeter has an open-deck design which is lightweight, highly rigid and has superb cooling efficiency.

The cylinder liners are made from cast iron and are dry types which are totally cast with aluminum cylinder block. Seven main journal block designs are employed to increase stiffness and quiet operation. The oil pump is located in the front center of the cylinder block and the water pump is located at the front of the left-cylinder bank. At the rear of the right-cylinder block is a separator which eliminates oil mist contained in the blow-by gas.

Oil separator cover Cylinder block (RH) Cylinder block (LH) C2-190

Fig. 7

9. Crankshaft

The crankshaft is supported by seven bearings to provide high rigidity and strength. The corners of the crankshaft journals and webs, as well as the crank pins and webs, are finished with fillet-roll work to increase strength. The seven crankshaft bearings are made from aluminum alloy and the No. 5 bearing is provided with a flanged metal to receive thrust force.

#1 #2 #3 #4 #5 #6 #7

C2-191

Fig. 8

10. Piston

The piston skirt has a "slipper" design to reduce weight and sliding. The oil control ring groove utilizes a slit design.

The piston pin is located in an offset position. The Nos. 1, 3 and 5 pistons are offset in the lower direction while the Nos. 2, 4 and 6 pistons are offset in the upper direction.

The piston head is recessed for both the intake and exhaust valves. It also has symbols used to identify the location and the direction of installation.

Three piston rings are used for each piston-two compression rings and one oil ring. The top piston ring has an inner-bevel design and the second piston ring has an interrupt design to reduce oil consumption.

Identification mark (Piston size) Location mark (Engine front side) Identification mark Location mark (Engine front side) Top ring (Inner-bevel) Second ring (Interrupt) Identification mark (Piston size) Oil ring Upper rail Spacer Lower rail

C2-192

Fig. 9

S SPECIFICATIONS AND SERVICE DATA

A: SPECIFICATIONS

ENGINE	Type		Horizontally opposed, liquid cooled, 6-cylinder, 4-stroke gasoline engine
	Valve arrangement		Belt driven, double over-head camshaft, 4-valve/cylinder
	Bore x Stroke	mm (in)	96.9 x 75 (3.815 x 2.95)
	Piston displacement	cm3 (cu in)	3,318 (202.46)
	Compression ratio		10.0
	Compression pressure (at 200 - 300 rpm)	kPa (kg/cm2, psi)	1,177 - 1,422 (12 - 14.5, 171 - 206)
	Number of piston rings		Pressure ring: 2, Oil ring: 1
	Intake valve timing	Opening	4° BTDC
		Closing	52° ABDC
	Exhaust valve timing	Opening	55° BBDC
		Closing	9° ATDC
	Idling speed [At N or D position]	rpm	610±100 (No load)
	Firing order		1 → 6 → 3 → 2 → 5 → 4
	Ignition timing	BTDC/rpm	20±8°/610

B: SERVICE DATA
Unit: mm (in)

Belt tension adjuster	Adjuster rod protrusion			15.4 - 16.4 (0.606 - 0.646)
Belt tensioner	Spacer O.D.			16 (0.63)
	Tensioner bush I.D.			16.16 (0.6362)
	Clearance between spacer and bush		STD	0.117 - 0.180 (0.0046 - 0.0071)
			Limit	0.230 (0.0091)
	Side clearance of spacer		STD	0.37 - 0.54 (0.0146 - 0.0213)
			Limit	0.8 (0.031)
Camshaft	Bend limit			0.02 (0.0008)
	Cam lobe height	Intake	STD	39.05 - 39.15 (1.5374 - 1.5413)
			Limit	38.90 (1.5315)
		Exhaust	STD	39.85 - 39.95 (1.5689 - 1.5728)
			Limit	39.70 (1.5630)
	Camshaft journal OD	#1		31.946 - 31.963 (1.2577 - 1.2584)
		#2, #3, #4		27.946 - 27.963 (1.1002 - 1.1009)
	Thrust clearance	Intake	STD	0.03 - 0.09 (0.0012 - 0.0035)
			Limit	0.13 (0.0051)
		Exhaust	STD	0.02 - 0.08 (0.0008 - 0.0031)
			Limit	0.12 (0.0047)
	Oil clearance		STD	0.037 - 0.072 (0.0015 - 0.0028)
			Limit	0.10 (0.0039)
Camshaft gear	Backlash		STD	0.029 - 0.175 (0.0011 - 0.0069)
			Limit	0.30 (0.0118)
	Free distance between camshaft spring ends			24.88 - 28.88 (0.9795 - 1.1370)
Cylinder head	Surface warping limit			0.05 (0.0020)
	Surface grinding limit			0.30 (0.0118)
	Standard height			127.5 (5.020)
Valve seat	Refacing angle			90°
	Contacting width	Intake	STD	1.0 (0.039)
			Limit	1.7 (0.067)
		Exhaust	STD	1.5 (0.059)
			Limit	2.2 (0.087)
Valve guide	Inner diameter			6.000 - 6.012 (0.2362 - 0.2367)
	Height above head			8.5 (0.335)
Valve	Head edge thickness	Intake	STD	0.8 (0.031)
			Limit	0.6 (0.024)
		Exhaust	STD	1.0 (0.039)
			Limit	0.8 (0.031)
	Stem diameter	Intake		5.955 - 5.970 (0.2344 - 0.2350)
		Exhaust		5.945 - 5.960 (0.2341 - 0.2346)

STD: Standard ID: Inner diameter OD: Outer diameter