GM has only produced 200 all aluminum ZL1
engines, which is sure to make it a collectors item. The Ram
Jet ZL1 is based on the
legendary all aluminum ZL1 first
introduced in 1969 that was in a limited number of 1969 Camaros
and Corvettes. The new Ram Jet ZL1 has some modern updates such
as improved main webs and provisions for a roller cam. Original
tooling that was used in 1969 was modified to update the block.
Each ZL1 has a three digit serial number machined into the Ram
Jet cast logo on the valve covers. The new ZL1 will produce 510
H.P @ 5750 rpm and 493 lbs of torque @ 4250 rpm. The ZL1
contains a 10.2 to 1 compression ratio with a 640/598 lift on a
solid roller cam shaft using roller rocker arms with an 1.7 to
1 ratio that are held in place with 7/16 studs. The aluminum
cylinder heads, that come on the ZL1, have stainless steel 2.25
intake and 1.88 exhaust valves with race quality springs. Valve
lash settings are .016 for the intake and .018 for the exhaust.
The air that is pulled through a 58mm throttle body should be
mixed with 93 octane fuel due to the 10.2 to 1 compression
ratio. An easy wiring harness and preprogrammed EMC computer
are included with the ZL1.
New
GM Ram Jet ZL1
Limited Edition Fuel Injected ZL1 454
This ZL1 is #67 out of only 200 all
aluminum ZL1’s produced. When S&P completes this
engine, it will be put into the ‘37 Ford belonging to
Phil Moss of West Port, Kentucky. Phil has chosen the
durability of a 4L80E transmission behind his ZL1 for the
reason that the engine produces 510 H.P and 493 lbs of torque
and he also wanted to have overdrive.
This is our first look at the ZL1 as it
arrived direct from GM. The upper plenum, throttle body and
throttle linkage were packaged in a seperate box in the front
of the crate. A complete instruction manual, the computer and
harness are mounted on the intake. The ZL1 is shipped with a
standard rotation short aluminum water pump.
The block is being hand worked with a die
grinder to prepare it for polishing. Once all of the
tight places are done, then a larger hand buffer will be used
to polish the larger areas and another die grinder will be used
to polish the tight places.
In order to polish the heads, all of the
valves, springs and retainers are removed. The tight areas of
the heads are worked by hand just as the block is. Only the
larger areas of the heads can be polished using an stationary
buffing machine. When the heads are finished they will be sent
to the engine shop, cleaned and reassembled.
Preparing the valve covers and manifold
for chrome requires the same extensive hand work as the block
and heads before the triple chrome plating process can begin.
The chroming process starts with a zinc aid which adheres the
copper to the aluminum. Then a cyanide copper strike, which is
followed by an acid copper, is applied with buffing between
coats. This fills any
imperfections in the aluminum and makes
ready for nickel and chrome.
1. Buffing the copper between coats on
the ZL1 RamJet plenum in preparation for nickel.
2. Polishing the tight areas of the
manifold between coats before applying the nickel.
3. Placing the intake manifold into the
nickel tank before it is chrome plated.
After the block had been polished, Adam
Gunn in the engine building department removed the steel oil
pan and timing chain cover so that they could be sent to
chrome. He then installed the heads onto the block using new GM
gaskets. The ZL1 comes with a head studs and nuts that are 100
percent magnaflux and inspected rather than standard head
bolts. The aluminum rocker arms that come installed on the ZL1
are extruded aluminum alloy with a push rod seat of 8620 steel.
Bearings and fulcrum axle have an extra wide design for load
distribution. The roller tip axle is made from 4130 steel and
the roller tip is machined and ground from 8620 steel. Roller
and valve stem tips are provided with a constant oil supply to
reduce friction. The main body is slotted to provided extra
roller arm stud clearance. Needle bearing fulcrum reduces
friction and adds horse power.
With the intake back from the chrome
shop, Adam began to install it along with the fuel rail,
harness, computer (which is mounted on the intake under the
fuel rail) and polished
distributor. Before Adam received the intake he began to
install the S&P brackets, pulleys and the chromex coated
headers. Since the ZL1 has taller valve covers to clear the 1.7
to 1 rocker arms, it was necessary to machine a special air
bracket to clear the GM valve cover.
With the air temperature sensor, MAP
sensor and all vacuum fittings installed, the plenum is bolted
to the intake with stainless steel bolts. Anti-seize is applied
to all bolts to prevent electrolysis of two different metals.
With the plenum bolted to the intake,
Adam installed the ZL1 throttle body. This is a 58mm, which is
larger than the 502/502 hp Ram jet.
S&P offers a polished aluminum air
foil that will enhance the air flow through the throttle body
and increase horse power.
The ZL1 valve covers were installed.
These valve covers have the ZL1 serial number on them and only
come with the ZL1. They are not available any other way. To
ensure ample
electrical power for Phil’s
‘37, S&P installed a chromed 145 amp alternator.
Sources
GM Performance Parts
1.800.GM USE US
www.Goodwrench.com
Street & Performance
#1 Hot Rod Lane
Mena, Ar 71953
479.394.5711
www.hotrodlane.cc
After the plenum, throttle body, valve
covers and accessories were bolted on, Adam install a set of
Taylor’s custom spark plug wires in a purple color to
match the finish on the 37. Note that we chromed everything on
the engine that we could. Phil wanted to spend more time
driving his car than cleaning it. All that is left is for the
proud new owner to pick up his engine and transmission.
