head CHEVROLET CAMARO 1982 Repair Guide
Page 468 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 468
7. Compare your hot oil pressure reading
to that given in the chart. If the
reading is low, check the cold pressu re reading against the chart. If the
cold pressure is well above the spec ification, and the hot reading was
lower than the specificat ion, you may have the wr ong viscosity oil in the
engine. Change the oil, making sure to use the proper grade and
quantity, then repeat the test.
Low oil pressure readings could be attributed to internal component wear, pump
related problems, a low oil leve l, or oil viscosity that is too low. High oil pressure
readings could be caused by an overfilled crankcase, too high of an oil viscosity
or a faulty pressure relief valve.
BUY OR REBUILD?
Now that you have determined that your engine is worn out, you must make
some decisions. The question of whether or not an engine is worth rebuilding is
largely a subjective matter and one of per sonal worth. Is the engine a popular
one, or is it an obsolete model? Are parts available? Will it get acceptable gas
mileage once it is rebuilt? Is the car it's being put into worth keeping? Would it
be less expensive to buy a new engine, have your engine rebuilt by a pro,
rebuild it yourself or buy a used engine from a salvage yard? Or would it be
simpler and less expensive to buy another car? If you have considered all these
matters and more, and have still decided to r ebuild the engine, then it is time to
decide how you will rebuild it.
The editors of this information feel that most engine machining should be
performed by a professional machine shop. Don't think of it as wasting money,
rather, as an assurance that the job has been done right the first time. There
are many expensive and spec ialized tools required to perform such tasks as
boring and honing an engine block or having a valve job done on a cylinder
head. Even inspecting the parts requires expensive micrometers and gauges to
properly measure wear and clearances. Al so, a machine shop can deliver to
you clean, and ready to assemble parts, saving you time and aggravation. Your
maximum savings will come from perf orming the removal, disassembly,
assembly and installation of the engine and purchasing or renting only the tools
required to perform the above tasks. Depending on the particular
circumstances, you may save 40 to 60 perc ent of the cost doing these yourself.
A complete rebuild or overhaul of an engine involves replacing all of the moving
parts (pistons, rods, crankshaft, camsha ft, etc.) with new ones and machining
the non-moving wearing surfaces of t he block and heads. Unfortunately, this
may not be cost effective. For instanc e, your crankshaft may have been
damaged or worn, but it can be machined undersize for a minimal fee.
So, as you can see, you can replace ev erything inside the engine, but, it is
wiser to replace only those parts whic h are really needed, and, if possible,
repair the more expensive ones. Later in this section, we will break the engine
down into its two main components: t he cylinder head and the engine block. We
will discuss each component, and the re commended parts to replace during a
rebuild on each.
Page 470 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 470
•
Never hot tank aluminum parts (the c austic hot tank solution will eat the
aluminum.
• Remove all aluminum parts (identif ication tag, etc.) from engine parts
prior to the tanking.
• Always coat threads lightly with engine oil or anti-seize compounds
before installation, to prevent seizure.
• Never overtighten bolts or spark plugs especially in aluminum threads.
When assembling the engine, any parts that will be exposed to frictional contact
must be prelubed to provide lubricatio n at initial start-up. Any product
specifically formulated for this purpos e can be used, but engine oil is not
recommended as a prelube in most cases.
When semi-permanent (locked, but removabl e) installation of bolts or nuts is
desired, threads should be cleaned and coat ed with Loctite® or another similar,
commercial non-hardening sealant.
CLEANING
Before the engine and its components ar e inspected, they must be thoroughly
cleaned. You will need to remove any eng ine varnish, oil sludge and/or carbon
deposits from all of the com ponents to insure an accurate inspection. A crack in
the engine block or cylinder head can eas ily become overlooked if hidden by a
layer of sludge or carbon.
Fig. 1: Use a gasket scraper to remove t he old gasket material from the mating
surfaces
Page 472 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 472
Fig. 3: Clean the piston ring grooves using a ring groove cleaner tool, or ...
Fig. 4: ... use a piece of an old ring to clean the grooves. Be careful,\
the ring
can be quite sharp
When cleaning the cylinder head, remove carbon from the combustion chamber
with the valves installed. This will avoid damaging the valve seats.
Page 476 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 476
Before attempting to repair a threaded
hole, remove any snapped, broken or
damaged bolts or studs. Penetrating oil ca n be used to free frozen threads. The
offending item can usually be removed with locking pliers or using a screw/stud
extractor. After the hole is clear, the thread can be repaired, as shown in the
series of accompanying illustrations and in the kit manufacturer's instructions.
ENGINE PREPARATION
To properly rebuild an engine, you must fi rst remove it from the vehicle, then
disassemble and diagnose it. Ideally you should place your engine on an engine
stand. This affords you the best access to the engine components. Follow the
manufacturer's directions for using the stand with your particular engine.
Remove the flywheel or fl explate before installing the engine to the stand.
Now that you have the engine on a stand, and assuming that you have drained
the oil and coolant from the engine, it's ti me to strip it of all but the necessary
components. Before you start disassembli ng the engine, you may want to take
a moment to draw some pictures, or fabr icate some labels or containers to mark
the locations of various components and the bolts and/or studs which fasten
them. Modern day engines use a lot of littl e brackets and clips which hold wiring
harnesses and such, and these holders are often mounted on studs and/or bolts
that can be easily mixed up. The manufacturer spent a lot of time and money
designing your vehicle, and they wouldn't have wasted any of it by haphazardly
placing brackets, clips or fasteners on t he vehicle. If it's present when you
disassemble it, put it back when you asse mble, you will regret not remembering
that little bracket which holds a wire har ness out of the path of a rotating part.
You should begin by unbolting any accessories still attached to the engine, such
as the water pump, power steering pump, alternator, etc. Then, unfasten any
manifolds (intake or exhaust) which were not removed during the engine
removal procedure. Finally, remove any covers remaining on the engine such
as the rocker arm, front or timing cove r and oil pan. Some front covers may
require the vibration dam per and/or crank pulley to be removed beforehand.
The idea is to reduce the engine to the bar e necessities (cylinder head(s), valve
train, engine block, crankshaft, pistons and connecting rods), plus any other 'in
block' components such as oil pumps, balance shafts and auxiliary shafts.
Finally, remove the cylinder head(s) from the engine block and carefully place
on a bench. Disassembly instructions fo r each component follow later in this
section.
CYLINDER HEAD
There are two basic types of cylinder heads used on today’s automobiles:
the Overhead Valve (OHV) and the Over head Camshaft (OHC). The latter can
also be broken down into two subgr oups: the Single Overhead Camshaft
(SOHC) and the Dual Overhead Camshaft (DO HC). Generally, if there is only a
single camshaft on a head, it is just referred to as an OHC head. Also, an
engine with a OHV cylinder head is also known as a pushrod engine.
Page 477 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 477
Most cylinder heads these days are made of
an aluminum alloy due to its light
weight, durability and heat transfer qualit ies. However, cast iron was the
material of choice in the past, and is st ill used on many vehicles today. Whether
made from aluminum or iron, all cylinder heads hav e valves and seats. Some
use two valves per cylinder, while the more hi-tech engines will utilize a multi-
valve configuration using 3, 4 and
even 5 valves per cylinder. When the va lve contacts the seat, it does so on
precision machined surfaces, which seal s the combustion chamber. All cylinder
heads have a valve guide for each valve. The guide centers the valve to the
seat and allows it to move up and down within it. The clearance between the
valve and guide can be critical. Too much clearance and the engine may
consume oil, lose vacuum and/or damage the seat. Too little, and the valve can
stick in the guide causing t he engine to run poorly if at all, and possibly causing
severe damage. The last component all cylinder heads have are valve springs.
The spring holds the valve against its s eat. It also returns the valve to this
position when the valve has been opened by the valve train or camshaft. The
spring is fastened to the valve by a retainer and valve locks (sometime\
s called
keepers). Aluminum heads will also have a valve spring shim to keep the spring
from wearing away the aluminum.
An ideal method of rebuilding the cylin der head would involve replacing all of
the valves, guides, seats, springs, et c. with new ones. However, depending on
how the engine was maintained, often this is not necessary. A major cause of
valve, guide and seat wear is an improperly tuned engine. An engine that is
running too rich, will often wash the lubric ating oil out of the guide with gasoline,
causing it to wear rapidly. Conversely, an engine which is running too lean will
place higher combustion temperatures on the valves and seats allowing them to
wear or even burn. Springs fall victim to the driving habits of the individual. A
driver who often runs the engine rpm to the redline will wear out or break the
springs faster then one that stays well below it. Unfortunately, mileage takes it
toll on all of the parts. G enerally, the valves, guides, springs and seats in a
cylinder head can be machined and re-used, saving you money. However, if a
valve is burnt, it may be wise to replace all of the valves, since they were all
operating in the same environment. The same goes for any other component\
on
the cylinder head. Think of it as an insurance policy against future problems
related to that component.
Unfortunately, the only way to find out wh ich components need replacing, is to
disassemble and carefully check each piece. After the cylinder head(s) are
disassembled, thoroughly clean all of the components.
DISASSEMBLY
Before disassembling the cylinder head, you may want to fabricate some
containers to hold the various parts, as some of them can be quite small (such
as keepers) and easily lost. Also keeping yourself and the components
organized will aid in assembly and reduce confusion. Where possible, try to
maintain a components original location; th is is especially important if there is
not going to be any machine work performed on the components.
Page 478 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 478
1. If you haven’t already removed t
he rocker arms and/or shafts, do so
now.
2. Position the head so that the springs are easily accessed.
Fig. 1: When removing an OHV valve spring, use a compressor tool to relieve
the tension from the retainer
3. Use a valve spring compressor tool, and relieve spring tension from the retainer.
Due to engine varnish, the retainer may stick to the valve locks. A gentle tap
with a hammer may help to break it loose.
Page 481 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 481
6. If equipped, remove the valve seal. If t
he seal is difficult to remove with
the valve in place, try removing the valve first, then the seal. Follow the
steps below for valve removal.
Fig. 6: Invert the cylinder head and wit hdraw the valve from the valve guide
bore
7. Position the head to allow acce ss for withdrawing the valve.
Cylinder heads that hav e seen a lot of miles and/or abuse may have
mushroomed the valve lock grove and/or tip, causing difficulty in removal of the
valve. If this has happened, use a metal f ile to carefully remove the high spots
around the lock grooves and/or tip. On ly file it enough to allow removal.
8. Remove the valve from the cylinder head.
9. If equipped, remove the valve spri ng shim. A small magnetic tool or
screwdriver will aid in removal.
10. Repeat Steps 3 though 9 until all of the valves have been removed.
INSPECTION
Now that all of the cyli nder head components are clean, it’s time to inspect
them for wear and/or damage. To accura tely inspect them, you will need some
specialized tools:
• A 0-1 inch micrometer for the valves
• A dial indicator or inside diam eter gauge for the valve guides
• A spring pressure test gauge
Page 482 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 482
If you do not have access to the proper
tools, you may want to bring the
components to a shop that does.
VALVES
The first thing to inspect are the valve heads. Look closely at the head, margin
and face for any cracks, excessive wear or burning. The margin is the best
place to look for burning. It should have a squared edge with an even width all
around the diameter. When a valve burns, the margin will look melted and the
edges rounded. Also inspect the valve head for any signs of tulipping. This will
show as a lifting of the edges or dishi ng in the center of the head and will
usually not occur to all of the valves. All of the heads should look the same, any
that seem dished more t han others are probably bad. Next, inspect the valve
lock grooves and valve tips. Check fo r any burrs around the lock grooves,
especially if you had to file them to remove the valve. Valve tips should appear
flat, although slight rounding with high mile age engines is normal. Slightly worn
valve tips will need to be machined flat. Last, measure the valve stem diameter
with the micrometer. Measure the area that rides within the guide, especially
towards the tip where most of the wear occurs. Take several measurements
along its length and compare them to each other. Wear should be even along
the length with little to no taper. If no minimum diameter is given in the
specifications, then the stem should not read more than 0.001 in. (0.025mm)
below the specification. Any valves that fail these inspections should be
replaced.
Fig. 7: Valve stems may be rolled on a flat surface to check for bends
Page 485 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 485
CYLINDER HEAD
There are several things to check on
the cylinder head: valve guides, seats,
cylinder head surface flatness, cracks and physical damage.
VALVE GUIDES
Now that you know the valves are good, you can use them to check the guides,
although a new valve, if available, is preferred. Before you measure anything,
look at the guides carefully and inspect t hem for any cracks, chips or breakage.
Also if the guide is a removable style (a s in most aluminum heads), check them
for any looseness or evidence of movem ent. All of the guides should appear to
be at the same height from the spring s eat. If any seem lower (or higher) from
another, the guide has moved. Mount a dial indicator onto the spring side of the
cylinder head. Lightly oil the valve stem and insert it into the cylinder head.
Position the dial indicator against the valve stem near the tip and zero the
gauge. Grasp the valve stem and wiggle towards and away from the dial
indicator and observe the readings. Mount the dial indicator 90 degrees from
the initial point and zero the gauge and again take a reading. Compare the two
readings for a out of round condition. Check the readings against the
specifications given. An Inside Diamete r (I.D.) gauge designed for valve guides
will give you an accurate valve guide bore measurement. If the I.D. gauge is
used, compare the readings wit h the specifications given. Any guides that fail
these inspections should be replaced or machined.
Fig. 11: A dial gauge may be used to che ck valve stem-to-guide clearance; read
the gauge while moving the valve stem
Page 486 of 875
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 486
VALVE SEATS
A visual inspection of the valve seats
should show a slightly worn and pitted
surface where the valve face contacts t he seat. Inspect the seat carefully for
severe pitting or cracks. Also, a seat t hat is badly worn will be recessed into the
cylinder head. A severely worn or rece ssed seat may need to be replaced. All
cracked seats must be replaced. A seat co ncentricity gauge, if available, should
be used to check the seat run-out. If run-out exceeds specifications the seat
must be machined (if no specification is given use 0.002 in. or 0.051mm).
CYLINDER HEAD SURFACE FLATNESS
After you have cleaned the gasket surf ace of the cylinder head of any old
gasket material, check the head for flatness.
Fig. 12: Check the head for flatness across the center of the head surface using
a straightedge and feeler gauge