ZL-1 Corvette

Full ZL1 Corvette Competition History click here!

The 1969 ZL-1 all aluminum 427 cubic inch Corvette motor
was the most powerful engine that was ever offered in
an American built automobile. It was the direct descendent
of the L-88 427 engine and the all aluminum Can Am racing engine of the same era.
Although factory rated at
430 HP, the actual output was
more like
585 HP after tuned headers were installed
in place of the restrictive factory exhaust manifolds.

 


When delivered from the factory, the standard exhaust manifolds may have suited quick
assembly line techniques, but they only slowed the Corvette's true acceleration potential.
So to resolve this problem, the factory contracted
Kustom Headers to build several sets of header/sidepipes for the true racing enthusiast, which could be purchased via the local
Chevrolet parts department. But due to the low production quantity of these headers, the prices
were extremely high.
Hooker Headers quickly bent a set of their own and offered them
at a much more reasonable price than the Kustom set.

Hooker established it's own niche with that marketing move.

 

A dome hood was necessary for intake manifold clearance.
This hood was released in 1968 with the cast iron block L-88.
Cowl induction was used at the rearmost base of the
dome for improved air induction to the

Holley 850 double pumper 4 barrel carb
.
This cowl induction trick alone cut seven seconds off
the car's zero to 140 MPH acceleration times!!!

 




To truly experience this car's handling and acceleration potential, it was to one's advantage to install the factory designed fender flares, which were also available through the parts department of the dealership. Larger, wider tires could then be used for improved cornering and acceleration.

Two factory test mules were made available to the press. A white convertible, which was set up for road racing duty, and a red coupe, which was set up as a "Saturday Night Special" for 1/4 mile drag racing action.

 

 

The red ZL-1 was equipped with a "beefed-up" automatic
transmission and 4.88:1 rear end gears. With 9" slicks
and open headers, every automotive reporter at the session
was running the 1/4 mile in 10.9 Sec. @ 132 MPH!!
This is an incredible feat considering that all you had to
do was to get in a car, buckle up, load up the torque
converter a few thousand RPM's,take your foot off the brake,
and in less than 11 seconds you've already driven through
the traps at the strip at a speed that most other street cars
could barely achieve with highway gears!! This red ZL-1 was set up by Corvette engineer Gib Hufstader.

 

 



The white Zl-1 was equipped with an M-22 "rock-crusher"
4-speed transmission and 3.70:1 rear end gears.
Even with this "road racing" setup, this car could cut the quarter mile in 12.1 Sec @ 116 MPH! 200 MPH could be attained with the proper higher rear end gears
(lower numerically).

This white car was set up by chief Corvette engineer
Zora Duntov.




One of the most successful Corvette racers to use
the ZL-1 motor consistently was
John Greenwood.
He achieved many victories in the SCCA, including a
national championship, and competed quite successfully in
long distance endurance racing. Here we find John
at the 1971 running of the 24 hours of Daytona endurance race.


If you want more info about the ZL1, then you need to have this
book in your collection. Click here for more ZL1 photos and info!

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