ZZ4 Engine Swap FAQ
installation on a 1971 Corvette
I have decided to write this
because of the numerous posts that always come up on Corvette Forum. Your
installation may vary due to options, transmission and year of your car so
this is a very basic installation paper.
engine itself comes with everything you need for installation but there
are some things that should be known about the engine configuration so you
can plan accordingly.
You can call Salle Chevrolet at 1-200-545-0048 or
visit www.sallee-chevrolet.com and they can custom build a ZZ4 based
engine for your application.
Here is how the engine is configured if
you buy it stock:
Part Number: 24502609
Displacement: 5.7-liter(350 c.i.)
Engine Block: 10105123 Four Bolt Main, Cast
Compression Ratio: 10:1
Pistons: High silicon aluminum
piston with offset pins, 10159436.
Crankshaft: 12556307 Forged
Connecting Rods: 10108688 PM rods
Camshaft: Hydraulic roller
Duration (Intake/Exhaust): 208�/221� @
.050\” tappet lift
Valve Lash (Intake/Exhaust):Zero/Zero
Heads: Aluminum, 58cc chambers, 12556463.
Valve Springs: LT4 chrome
Rocker Arm Ratio: 1.5:1, 10089648
HEI with centrifugal and vacuum advance, 1104067.
Spark Plugs: MR43LTS
Gap .045, AC FR5LS Gap .035, Rapid Fire #5 Gap .045.
Unleaded Premium 92 Octane
Ignition Timing: 12� BTDC @ 800 RPM, 36�
total @ 3,200 RPM with vacuum advance disconnected.
Max. Rec. RPM:
Technical Notes: Carburetor, spark plug wires, starter, oil
filter and oil filter adapter, and exhaust manifolds not included.
Distributor P/N 1104067 or melonized distributor gear P/N 10456413 must be
used on all crate engines with steel camshafts.
In the notes
section you will notice what is not included with the engine. This
section will explain them in more details.
Carburetor � I used my
Q-jet. I guess its up to you to figure out what you want. My Q-jet works
Spark plug wires � I used MSD�s 8.5mm superconductor wires.
I also changed my distributor to a MSD tach drive unit (P/N 8572) and a
6AL ignition box (P/N 6420) because my tach is driven off the distributor
and I didn�t want to use my old points. 75 and later can use the HEI unit
that comes with the engine and still have a functioning
Starter � I used the one off my old 350. A lot of people say
you should use a gear reduction starter but like most of us, I was on a
budget and couldn�t afford one. After a year the starter works fine and I
haven�t had any problems with it yet. My starter is a lifetime warranty
unit form Pep Boys so again, like the carburetor, it�s your
Oil filter and oil filter adaptor � I used the oil filter
adaptor off my old engine. Two bolts hold it on. Very easy to change
over and I haven�t had any problems with it. I use the PF25A
Exhaust manifolds � You can use your manifolds if you want
but keep in mind that the heads on the ZZ4 have �D� shaped exhaust ports
and they are a little higher that the old stock cast iron heads so you may
have to tweak your exhaust system a little if you use the stock manifolds.
I don�t recommend using Ram Horn Manifolds because you are going to
restrict breathing and hurt performance a little. I went with Headman
Headers that have �D� shaped tubes. They are full length with 3�
collectors but have the shorty design so clearance is not a problem. I
got them from Jim Pace www.paceparts.com and you can get them painted or
If you have a manual
transmission you cannot use your old flywheel. The ZZ4 has the new style
block with the one-piece rear main seal therefore the crank bolt pattern
is smaller (3.0� compared to 3.58� on the old style cranks). Depending on
your car and which transmission it came with, you need to figure out which
flywheel you need. Flywheels with two different diameters are used on
Chevrolet small-block V8, big-block V8, and V6/90� engines. Large
flywheels are 14\” in diameter, and have 168 teeth on the starter ring
gear. Small diameter flywheels are 12-3/4\” in diameter and have 153
teeth on the starter ring gear.
The difference in flywheel
diameters requires two distinct starter housings. Starter noses used with
large diameter flywheels have two offset bolt holes; starters for small
flywheels have two bolt holes which are parallel to the back of the block.
Most Chevrolet blocks are drilled for both types of starters. If you are
changing the diameter of your Chevrolet\’s flywheel, you can convert
your present starter to fit the new flywheel by installing the appropriate
starter nose, starter motor housing, found within each engine
classification. This is not an issue if you have an automatic because the
engine comes with a flexplate but you will have to note which starter nose
you have and change it accordingly. I used the 14� 168 tooth flywheel GM
Temperature sensors � The ZZ4�s head has a small
diameter temperature sensor port between #1 and # 3 cylinders. I know the
older small blocks used a larger diameter sensor at this location. I
tried 3 different sensors and all three were not calibrated to my gauge. I
decided to use my old sensor and there is a port in the intake manifold
that is the large diameter on the front left side of the manifold right
next to the thermostat housing. It is a little tight but it will clear
the upper radiator hose by about 1/8th of an inch. This area of the
engine runs 10o to 15o cooler that the head locations so keep this in mind
if you choose to put your temp sensor at this location.
� This is the biggest question most people have about the ZZ4 swap. This
is really not a big deal and there are three ways to remedy the
1. Use your old water pump. It will work and all you have to
do is grind down one of the timing chain cover bolts to make it fit
correctly. Test fit your old pump and you will get the idea. It�s easy
and doesn�t take a lot of time.
2. Get a new pump either aluminum or
cast iron. I went this route and bought an Edelbrock aluminum water pump.
If you do this you still have to grind the timing chain cover bolt.
Change the timing chain cover to the old style. I don�t recommend this as
it could induce an oil leak on your brand new engine. Why risk it. This
engine was dyno run at the factory and is check for quality and leaks
Fuel pump � I used a stock replacement fuel pump
(new) and have not had any problems with it. My car has the fuel return
line to the tank so I retained this feature.
Motor Mounts � I went
with Energy Suspensions Poly locking mounts. I like them and with the
405lb/ft of torque this engine puts out if the mount fails then it will
keep your fan and accessories from hitting stuff.
One point of
advice � I installed mine with the transmission installed on the engine.
If you didn�t take the transmission out of the car that�s fine. I just
found it easier to do it as one unit. I also used all new hoses and
GM\’s Recommended Crate Engine Start-up Procedure
Safety first! If the car is on the ground, be sure the emergency brake is
set, the wheels are chocked, and the transmission cannot fall out of gear.
2) Be sure to check the oil level in the engine and prime the oil
3) Run the engine between 2,000 and 2,5000 RPM\’s, with
no-load on the engine for the first 30 min.
4) Adjust the
distributor timing roughly by hand for a quick start up and smoothest idle
5) Adjust the carburetor settings, if necessary.
6) After the first 30 minutes of the engine running, set the ignition
timing according to the timing specifications.
7) Drive the vehicle
with varying speeds and loads on the engine for the first 30 miles. Be
sure not to use a lot of throttle of high RPM.
8) Run five or six
medium-throttle accelerations to about 5,000 RPM (55 to 60 MPH), then
letting off in gear and coasting back down to 20 MPH.
9) Run a
couple hard-throttle accelerations up to about 5000 RPM (55 to 60 MPH),
then letting off in gear and coasting back down to 20 MPH.
Change the oil and filter with recommended oil (10w30SG in most cases) and
11) Drive the next 500 miles normally, without high RPM\’s
(below 5,000 RPM), hard use, or extended periods of high loading.
12) Change oil and filter again.
13) Your engine is now ready
for many happy cruising miles!
Engine Oil Supplement P/N 1052367 can
be used any time during the life of the engine.