1991 ACURA NSX light

Lubrication Points

For the details of lubrication points and types of lubricants to be applied, refer to the Illustrated Index and various workprocedures (such as Assembly/Reassembly, Replacement, Overhaul, Installation, etc.) contained in each section.

No.

LUBRICATION POINTS

LUBRICANT

Engine
Transmission

Manual

Automatic

Brake Line (including anti-lock brake system)
Clutch Line Shift lever pivots (M/T)Release fork (M/T)Steering gearbox (Manual)
Steering boots Steering column bushings
Steering ball jointsSelect lever (A/T)
Pedal linkage Intermediate shaft
Brake master power pushrod
Trunk hinges Door hinges upper and lower
Door opening detents
Fuel filler lid
Front hood hinges and latch
Clutch master cylinder pushrod
Tilt lever

Parking brake cable end
Throttle cable end Rear hatch latchRetractable headlight pin contact area
Shift cable end and select cable end
Caliper Piston seal, Dust seal, Caliper pin, Piston
Recommended Engine Oil
API Service Grade: SG Fuel Efficient Oil:
Identified by the words, "Energy Conserving II" API Service Grade: SG
SAE viscosity: 10 W—30 recommended
Fuel Efficient Oil:
Identified by the words, "Energy Conserving II"
SAE Viscosity: See chart below.
API Service Grade: SF or SG SAE Viscosity: See chart below.
Honda Premium Formula Automatic Transmission
Fluid or an equivalent DEXRON® II type automatic

transmission fluid

Brake fluid DOT3 or DOT4
Brake fluid DOT3 or DOT4
Silicone grease with molybdenum disulfide
Multi-purpose grease
Silicone grease Recommended Manual Transmission Oil
API Service Grade: SF or SG
transmission oil viscosity forambient temperature ranges
Engine oil viscosity for
ambient temperature rangesProCarManuals.com

This engine has the following new features.

Type

Displacement
Bore x Stroke
Compression Ratio
Cam, Valve Mechanism
Valve Train
Fuel Supply System Water-cooled V6—90° Cross Flow
2,977 cm3(181.6cu-in)

90 x 78 mm
(3.54
x
3.07
in)
10.2
Dual Overhead Camshafts, VTEC Belt Driven
Sequential Multiport Fuel Injection (SFI)VTEC; High output and a broad power band is achieved through control of low-speed and high-speed valve operation
by the Engine Control Module (ECM).
(Two knock sensors are used to detect octane level of the fuel.)
Titanium connecting rods ; Accomodate high rotation speed and high output. Titanium material of light weight and
high strength is used for the connecting rods.
(Strength is at the same level as iron.)
(Weight is about 30% lighter than iron.)
New mechanism to the intake system; Increased low and middle speed torque and higher output can be achieved by
switching the chamber volume of the intake manifold according to engine speed. This is electronically-controlled.
Cooling system for the mid-ship engine:
Radiator located in front compartment (An aluminum alloy radiator and pipes made of aluminum alloy)
Engine room cooling fan
Expansion tank
The cylinder block is highly rigid with deep water jackets. In order to achieve lighter weight, magnesium is used for the following parts: Cylinder head coverIntake manifold cover
Intake manifold chamber
Major SpecificationsProCarManuals.com

Rocker Arms and Lost Motion Assemblies

Inspection

NOTE: When reassembling the primary rocker arm, care-

fully apply air pressure to the oil passage of the rocker

arm.

PRIMARY ROCKER ARM

MID ROCKER ARM

SECONDARY

ROCKER ARM

PISTONS

1. Inspect the rocker arm pistons. Push them

manually.

PRIMARY

MID

SECONDARY

Apply oil to the pistons when reassembling.

Bundle the rocker arms with rubber bands to

keep them together as sets.
LOST MOTION ASSEMBLY
2. Remove the lost motion assembly from the cylinder

head and inspect it. Pushing it gently with the finger

will cause it to sink slightly. Increasing the force on

it will cause it to sink deeper.

Push

NOTE:
Check piston movement
If they do not move smoothly, replace the rocker

arm assembly.
If the lost motion assembly does not move

smoothly, replace it.ProCarManuals.com

VALVE SPRING COMPRESSOR
Snap-on CF711
Valves, Valve Springs and Valve Seals

Replacement

NOTE: Identify valves and valve springs as they are re-
moved so that each item can be reinstalled in its original

position.

1. Using an appropriate-sized socket and plastic mallet, lightly tap the valve retainer to loosen the valve keep-
ers before installing the valve spring compressor.
PLASTIC MALLET

SOCKET

2. Install spring compressor. Compress spring and re- move valve keeper.

VALVE SPRING COMPRESSOR
ATTACHMENTEXTENSION

07MAF–PR9010A
VALVE SPRING
COMPRESSOR
ATTACHMENT

07757–PJ1010A
3. Install the special tool as shown.
VALVE SEAL

COMMERCIALLY AVAILABLE
VALVE GUIDE SEAL REMOVER

LISLE P/N 57900 OR KD 3350

SEAL

PULLER

4. Remove the valve guide seal.ProCarManuals.com

SEAT WIDTH
2. Carefully grind a 45° seat, removing only enough
material to ensure a smooth and concentric seat.
3. Bevel the upper edge of the seat with the 30° stone and the lower edge of the seat with the 60° stone.Check width of seat and adjust accordingly.
4. Make one more very light pass with the 45° stone to remove any possible burrs caused by the otherstones.

Valve Seat Width:
Standard:
IN
0.80-1.00
mm
(0.031-0.039
in)

EX 1.25-1.55 mm (0.049-0.061 in.)

Service Limit: IN 1.5 mm (0.059 in)
EX 2.0 mm (0.079 in)

1. Renew the valve seats in the cylinder head using a
valve seat grinder.
NOTE: If guides are worn (page 6-43), replace them(page 6-44) before grinding the valve seats.
Valve Seats
Reconditioning
5. After resurfacing the seat, inspect for even valveseating: Apply Prussian Blue compound to the valve
face, and insert valve in original location in the head,
then lift it and snap it closed against the seat sever-
al times.

ACTUAL

SEATING

SURFACE

VALVE
SEAT

PRUSSIAN BLUE COMPOUND
7. Insert intake and exhaust valves in the head and measure valve stem installed height.
Valve Stem Installed Height (IN and EX): Standard (New): 41.55-42.35 mm

(1.6358-1.6673 in)

Service Limit: 42.435 mm (1.6707 in)

VALVE STEM
INSTALLED HEIGHT

8. If
valve stem
installed
height
is
over
the
service
limit,
replace valve and recheck. If still over the service
limit, replace cylinder head; the valve seat in the head

is too deep.

6. The actual valve seating surface, as shown by the
blue compound, should be centered on the seat.
If it is too high (closer to the valve stem), you

must make a second cut with the 60° stone to
move it down, then one more cut with the 45°
stone to restore seat width.
If it is too low (closer to the valve edge), you must

make a second cut with the 30° stone to move
it up, then one more cut with the 45° stone to
restore seat width.
NOTE: The final cut should always be made with
the 45° stone.ProCarManuals.com

Cylinder Heads
Installation

2. Install the exhaust manifold covers.
Front:

HEATED OXYGEN

SENSOR

45 N .
m (4.5 kg-m, 33 Ib-ft)
Be careful not to damage.

6 x 1.0 mm
12 N .
m
(1.2 kg-m.

9 Ib-ft)

GASKET
Replace.

SELF-LOCKING
NUT

8x
1.25
mm
34 N .
m
(3.4 kg-m,

25 Ib-ft)

Replace.

EXHAUST MANIFOLD

COVER

(cont'd)

8x
1.25
mm

22 N
.
m
(2.2 kg-m.

16 Ib-ft) FRONT EXHAUST

MANIFOLD

Valve Installation

When installing valves in cylinder head, coat valve

stems with oil before inserting into valve guides, and

make sure valves move up and down smoothly.When valves and springs are in place, lightly tap the
end of each valve stem two or three times to ensure proper seating of valve and valve keepers (use ham-
mer handle bottom).

VALVE STEMS
HAMMER HANDLE
BOTTOM

NOTE: Tap the valve stem only along its axis so you do
not bend the stem.
Apply oil to the self-locking nut threads.
Always use new exhaust manifold gaskets.
1. Install the front and rear exhaust manifolds to each
cylinder head, then tighten the self-locking nuts in
a criss-cross pattern in two or three steps, beginning

with the inner nut.
Always use new head gaskets.
Cylinder heads and engine block surface must be
clean.
Turn the crankshaft so that No. 1 piston is at TDC
(page 6-26).
Install the cylinder heads in the reverse order of removal:ProCarManuals.com

Camshafts

Installation

CAUTION: Valve locknuts should be loosened and ad-

justing screws backed off before installation.

1. After wiping down the cam and journals in cylinder

head, lubricate both surfaces and install camshaft.

2. Turn the camshaft until its keyway is facing up. (No.

1 cylinder TDC).

3. Set a new O-ring and a dowel pin in the oil passage

of the No. 1 camshaft holder.

O-RING

(Replace.)

and

DOWEL PIN
Keyways

facing up.

4. Install the camshaft seal with the open side (spring)

facing in.

Lubricate cam lobes after reassembly.

CAMSHAFT SEAL

Seal housing surface should be dry.

Apply a light coat of oil to camshaft

and inner lip of seal. (cont'd)
After installing the rocker shaft orifice, try to

turn the rocker shaft to make sure that the

orifice has been inserted in the hole of rocker

shaft correctly. If the orifice is in place, it should

not turn.

Remove the rubber bands after installing the

rocker arms.
O-RING

Replace.
ROCKER SHAFT

ORIFICES
O-RING

Replace.
3. Install the orifices. If the holes in the rocker arm

shafts and the cylinder head are not in line with

each other, use a 12 x 1.25 mm bolt in the rocker

arm shaft to rotate the shaft.
ROCKER SHAFT

12 x
1.25
mm

BOLT
12 x
1.25
mm

BOLT
ROCKER SHAFT
ROCKER ARMS
RUBBER BAND
1. Install the lost motion assemblies.

2. Install the rocker arms while passing the rocker arm

shaft through the cylinder head.
Rocker Arms

Installation

Valve adjusting lockouts should be loosened and

adjusting screws backed off before installation.

The component parts must be installed in the

original locations.
Install the rocker arms in the reverse order of removal:

CAUTION:ProCarManuals.com

(cont'd)
LOCKNUT

7 x
0.75
mm

20 N
.
m
(2.0 kg-m.
14 Ib-ft)
LOCKNUT

7 x
0.75
mm

20 N .
m
(2.0 kg-m.
14 Ib-ft)
EXHAUST:
6. Tighten locknut and check clearance again. Repeat
adjustment if necessary.
INTAKE:
3. Manually inspect the rocker arms for independent
operation (page 6-52, 53)
4. Adjust valves on No.1 cylinder.
TAPPET ADJUSTER

07MAA–PR70110

TAPPET LOCKNUT
WRENCH

07MAA–PR70120

EXHAUST:
NOTE: Use a mirror to check if the special tool is

positioned on the locknut correctly.
Adjusting screws are on primary and secondary
rocker arms.

Intake: 0.15-0.19 mm (0.006-0.007 in)
Exhaust: 0.17-0.21 mm (0.007-0.008 in)

5. Loosen locknut and turn adjustment screw until feel-
er gauge slides back and forth with slight amount

of drag.

INTAKE:ProCarManuals.com