A CRG Research Report
COPO 427: The Relentless Pursuit of Acceleration
© 2002-2007, Camaro Research GroupPrimary Author -
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Reviewed by the CRG Last Edit: 03-Aug-07 Previous Edit: 27-Jun-2002 Original Release: 27-Jun-2002 |
| C R G | CRG Reports | Exterior | Engine | 1967 Model ID |
| Numbers Decode | General Info | Interior | Transmission | 1968 Model ID |
| Drivetrain Decode | Options | Underhood | Chassis | 1969 Model ID |
A CRG Research Report
COPO 427: The Relentless Pursuit of Acceleration
© 2002-2007, Camaro Research Group|
Reviewed by the CRG Last Edit: 03-Aug-07 Previous Edit: 27-Jun-2002 Original Release: 27-Jun-2002 |
The transition to aluminum was not an easy one. Most of the
1967 season was spent making the new engine survive. By the
end of the season the bugs had been worked out and the
aluminum 427 engine was powerful and reliable. At that time
Jim Hall was the exclusive customer for the engine. For the
1968 Can-Am season other racers were able to acquire it,
most notably McLaren Racing with its famous orange cars. It
was extremely successful and Chevrolet began to think the
engine could have a market as an option in the Corvette. It
was transferred to the production engine group and some
efforts were made to publicize it. Hot Rod magazine did a
feature article on it with a cover photo for the December
1968 issue.
In production form, the engine differed from Can-Am
configuration. The dry-sump oil passage was eliminated and
provision for a mechanical fuel pump added. Production
tooling was developed for the block (casting #3946052),
cylinder heads (#3946074), and intake manifold (#3933198). A
new aluminum water pump was to be included (and at least one
and perhaps two Camaros were built with it), but last minute
testing raised reliability questions.
Chevrolet continued to develop the Can-Am version of the
aluminum big block for racing, progressing to a liner-less
390-alloy block buildable in displacements of 430, 441, 494
and 510 cubic inches. These did not have provision for a
mechanical fuel pump. They were never used in production and
few were produced.
Some
new component parts were necessary to accommodate the ZL-1
engine. New "HQ" code front springs were developed for the
weight change. Engineering drawings were produced detailing
the assembly of the K66 transistorized ignition system in a
1969 Camaro, including the design of an ignition amplifier
mounting plate and a small harness to adapt the K66 ignition
to the Camaro engine wiring.
ZL-1 cylinder heads do not have an exhaust heat crossover
passage so a spacer was used in place of the heat-riser
valve on the RH exhaust manifold. Also because of this, the
carburetor had no choke. The AMA specs specified an 850 cfm
Holley model #4296 carburetor. But due to supply problems
most cars were built with 780 cfm Holley model #4346
carburetors, though many were later retrofitted with the
#4296. A rebuildable hi-performance AC fuel pump was used.
The ZL-1 engine was built with a crankcase windage tray that
interfered with the baffle in the production 4-quart oil
pan. For this installation the standard pans were modified
by removing the baffle.
Fred Gibbs' drag racing experience had found the limits of
the standard production rear axle. A stronger positraction
unit with larger pinion and axle gears was developed. This
new unit was used with a heat-treated 4.10:1 ring and
pinion. It was coded "BE", instead of the standard 4.10
Camaro axle code of "BV".
The remainder of the car was built using standard assembly
procedures and components as employed on a Camaro SS with
the L78 engine, with some other exceptions. A document
titled "Exception control letter sheet" was used to outline
parts that were to be deleted and / or substituted from the
SS L78 package. One example is the starter: an L78 used an
11" clutch, the ZL-1 used the 10.34", and so starter 1108418
was replaced with 1108351 on the 4-speed and 1108400 on the
automatics. This system also explains why COPO's built as
rally sports do not have the rally sport fender emblems. The
"Camaro SS" badging was initially specified and the document
"deducted" the SS, leaving only the "Camaro" emblem. There
was no external indication of the engine. Assembly line
workers wrote "427" in crayon on the inside of the fender
extensions so the fenders would not be pierced for emblems
as all other 8 cylinder Camaros were. All ZL-1 cars were
equipped with AIR pumps and Gibbs' cars were produced with
standard N10 dual exhaust.
Since usage in both the Corvette and Camaro looked likely,
engine assembly codes "ME/MG" for Corvette 4 speed/automatic
and "ML/MM" for Camaro 4-speed/automatic were added to
service documentation. The Camaro engine codes are in a
listing headed "427 Camaro" and are described as COPO 9560.
Also listed are codes "MV" and "MX", described as RPO ZL-1.
(More on these two codes later.)
Engine production eventually totaled 80 "ME", 14 "MG", 54
"ML", and 34 "MM". Many bare blocks and heads were also
sold.
There
were difficulties immediately. Chevrolet dealers were
ordering far more Camaros than the plants could build.
Normal production scheduling would have meant the first ZL-1
cars would be produced mid-January, too late for Fred Gibb
to prepare his car for the first AHRA meet in Phoenix.
Concern was expressed to the right people and on December
31, 1968, two identical Dusk blue ZL-1/automatic 1969
Camaros arrived at Gibb Chevrolet. On the bottom of the one
Body Broadcast Copy was a note:
9560BA SHIP 1230 ESTES REQUEST RED HOT PILOT 427 ENGINE OPT 9560BAAs a harbinger of things to come, it was 22 below zero in La Harpe that day and neither car would start. The #2 car was sold to a private individual. Gibb and partner Dick Harrell prepared the #1 car in three short weeks and arrived at Phoenix only to fail technical inspection. Chevrolet had built the car with a carburetor that did not match the part number listed in the AMA specifications. Once again some calls were made and soon a Chevrolet engineer arrived in Phoenix with the correct carburetor. Although it did well this first time out, it did not win its class. It had a successful racing history, winning the AHRA Pro Stock Championship in 1971. The car was sold at the end of the 1971 season. It would be many years before it returned home.
The telling blow for COPO 9560 was the price. Gibb is
quoted as saying he believed the cars would list for around
$4900. Unfortunately for Gibb, the new edict at Chevrolet
came through that options had to be priced according to
production costs. Just the "HIGH PERFORMANCE UNIT" option
was priced at $4160.50. (For reasons unknown, subsequent
ZL-1s were priced at $4160.15) The mandatory power disc
brakes and transmission option pushed sticker prices over
$7300. This was far more than a well equipped 1969 Corvette
and would be roughly equivalent to today's Z06 Corvette.
Not only would the cars not sell, Gibb
likely was unable to pay for them. Gibb plead his case,
and in an unprecedented move, Chevrolet agreed to the return
of many ZL-1 Camaros. The cars were shipped back to Norwood,
Ohio beginning in May 1969 and Chevrolet began to shop the
cars around. Gibb also wholesaled cars directly to other
dealers who would soon learn what he knew: they were
sale-proof. Many dealers removed and sold the ZL-1 engines,
replacing them with iron 396 or 427s, adding stripes and mag
wheels, doing whatever it took to sell the white elephants.
Several were stolen and never recovered. Despite that, Gibb
sold his last new 1969 ZL-1 Camaro in 1972 (with the aid of
a $1000 rebate from Chevrolet). It was re-possessed and
returned it to Gibb in 1973.
Possibly because the racing sanctioning bodies required
proof, Chevrolet retained a list of ZL-1 Camaro vehicle
identification numbers. The linked file contains a listing
of the 50 cars initially shipped to Fred Gibb Chevrolet. All
the built-for-Gibb cars had the standard interior in black;
the automatic cars were column-shifted. Most of these cars
were ultimately sold by other Chevrolet dealers.
Fred Gibb may have believed the ZL-1 Camaro was his
exclusively. Compounding his difficulty in selling the cars
was the fact that other Chevrolet dealers had learned of the
COPO and ordered 19 additional ZL-1 Camaros. Some of these
cars had more optional equipment. Many of these Camaros
found the same cold reception as the Gibbs' cars and
suffered the same fate: engine swaps, theft, modifications.
Several production ZL-1 Camaros were raced by Dick Harrell,
Shay Nichols, Ken Barnhart, Malcolm Durham, Lamar Walden,
and others. It should be noted that some 1969 Camaros raced
with ZL-1 engines in SS/C were not part of the production
run. Bill Jenkins and Jungle Jim Liberman retrofitted
engines into their racecars.
For a car with a total production run of only 69, the
enthusiast magazines of the era took notice. Super Stock was
the first, featuring the #1 car in full AHRA trim, and
another of Gibb's, believed to be #5, in the May 1969 issue.
The street version ran an incredible 11.64/122 mph with open
headers and small 6-1/2 inch slicks. The #1 car ran
10.29/132 mph. Popular Hot Rodding covered the same test in
the July 1969 issue. Hot Rod reviewed this test in the July
1998 issue. Hi-Performance Cars August 1969 tested the
now-famous #3 ZL-1 and ran 13.16/110 mph on E70x15 tires
with closed exhaust and an AIR pump. Drag Racing magazine
had Baldwin-Motion build them one and it ran 11.48/122 mph.
The potential was certainly there. But the car that should
have become a dominant force in drag racing never quite
lived up to its promise. High cost was certainly a factor,
making the production run low. Durability issues also came
into play. Many cars were sold without the ZL-1 engine.
Perhaps an "L-88" Camaro may have been a better idea.
By late 1969 there was little corporate interest in the ZL-1
engine program. The aggressive people that made it happen
were moving out of Product Performance due to the increasing
need for emissions and accident protection development. The
driving force behind the Camaro, Pete Estes, left Chevrolet
in February 1969 to become a GM Group Vice-President. He was
replaced by John DeLorean from Pontiac, oft credited as the
father of the GTO. DeLorean was a performance enthusiast but
he was on a mission. Chevrolet was losing market share and
was marginally profitable. Budgets were tightened, tougher
controls put in. By 1970, Product Performance was no more.
Much
ZL-1 Camaro documentation has been located, and some
representative pieces are illustrated in this section. The
acronym "ZL-1" does not appear on any of it. The entire
option was indicated by "9560AA" for a 4-speed and "9560BA"
for an automatic.
All things considered, it may be hard to believe Chevrolet
actually considered a Regular Production Option ZL-1 Camaro.
In April 1969 a Camaro SS-RS hardtop was delivered to the
Tech Center. It was fitted with a de-tuned version of the
ZL-1 engine; both automatic and 4-speed versions were
considered, codes "MV" and "MX". It was painted black with black
vinyl top, and had a
larger front spoiler, chrome exhaust tips and some special
touches such as blacked out trim, gold striping, and ZL-1
badging. The car appeared in several publications during
1969-70 but was never considered for production due to the
projected list price of $8500. Period photos of the car
depict it with both chrome and body-color front bumper.
While this created the impression there were two of the prototypes,
Chevrolet records indicate only one ZL-1 show car was built.
Chevrolet
actually did offer the ZL-1 engine as Corvette RPO ZL1. The
oft repeated but unverified production quantity is three.
One fully documented car survives, a yellow hardtop, VIN
194379S729219, on display as of this writing at Roger's Corvette
Center, Maitland (near Orlando), Florida. A white hardtop
also is in a private collection, sans factory documentation.
Several other Corvette ZL-1 cars have appeared, but only the
one is believed to be fully documented.
Bill
was an engineer with Oldsmobile who had built a number of
street machines and racecars utilizing the ZL-1 engine,
starting with the Kellmark GT in 1976. In 1978 he became
aware of the fact that Chevrolet had built a number of 1969
Camaros with the ZL-1 engine and became determined to own
one. His persistence finally paid off in 1981 when he
located the #3 car nearby. Although it had some bolt-on
racing modifications and a different engine, it had never
been cut or repainted and had only 18,000 miles. Rather than
restoring the car, a correct ZL-1 engine was assembled and
the car thoroughly detailed. Today it is one of the most
original ZL-1 Camaros and is now in a private collection.
#3 has been featured in numerous automotive publications.
The original engine exists but, as of this writing, past owners
of the car have been unable to acquire it.
Bill has acquired a substantial amount of paperwork and
engineering documentation concerning the cars and the ZL-1
engine. The purchase of the #3 car led Bill to contact Vince
Piggins, then with Chevrolet's Product Promotion
Engineering. Piggins had recorded all of the ZL-1 Camaro
VIN's in a long-forgotten file. He was able to locate them
and confirm the #3 car was a ZL-1. Vince then provided the
list to Super Chevy magazine, which printed it in the August
1981 issue, albeit with a few typos.
In
June 1988, Bill was to locate an even more significant car -
the first ZL-1 Camaro built. The car had been raced for
almost 20 years and was in need of a tremendous amount of
work. Rather than attempt to restore the car to as-built
condition, it was returned to its 1969 AHRA form as raced by
Dick Harrell and Fred Gibb. Bill recently acquired the
original block.#4 124379N608214 Cortez silver automatic I personally located #4 parked on a lawn in Idaho in 1987. It had been raced for a few years but not extensively modified. A frame-off restoration was completed in 1990 and the car is now in a private collection. #16 124379N608395 Hugger orange 4-speed Believed to be the only remaining original owner ZL-1 Camaro. Purchased directly from Fred Gibb by Ken Barnhart, the car was raced from 1969-1975. Ken still shows the car and occasionally races it in nostalgia events. #18 124379N609510 Dusk blue 4-speed One of the cars Gibb returned. The car was sold new in Virginia and repossessed by GMAC. The second owner raced it sparingly, sold it and bought it back a few years later. It became the famous USCC "Raffle Car." Original engine. #30 124379N610168 Hugger orange 4-speed Sold new by Gibb, the car was raced as a super-stocker for many years, never street driven. In excellent condition with original engine intact, it is now restored to virtually perfect condition and has been featured in a number of publications. #33 124379N610732 Hugger orange 4-speed #52 124379N620934 Le Mans blue automatic Sold new by Rathmann Chevrolet in Florida, both cars went to Melbourne Australia to be raced. #33 is a road racer, #52 was a drag racer. #33 has recently been restored to its original racing trim and remains "down under". #52 was reportedly wrecked and remains sent to a landfill. #54 124379N635720 Le Mans blue automatic Sold new in Canada, this is the only one of the 22 automatics to be equipped with a console. The car also has factory instrumentation and the white houndstooth interior. The engine was removed early and the car ended up in Vancouver, BC where it was purchased in the mid-80s. The original engine has been acquired and a meticulous restoration is nearing completion. #55 124379N641266 Le Mans blue 4-speed One of the more famous ZL-1 Camaros. It has Rally-Sport equipment along with many other options. The car is in excellent original condition with less than 10,000 actual miles and has been the subject of many magazine feature articles. #68 124379N650643 Cortez Silver 4-speed Another RS, this ZL-1 was raced by its original owner for many years. The car is now beautifully restored and has the DX1 hood stripe.
Also considered an "insider" at Chevrolet in those days was
another Chevrolet dealer actively involved in racing, Don
Yenko. His family owned a dealership in Canonsburg, PA,
which had been modifying Corvettes and Corvairs for years,
marketing them as produced by Yenko Sports Cars Inc. When
the Camaro was introduced in 1967, Yenko installed 427
engines and sold them as the "SYC Camaro". This continued
in 1968 but the process of swapping the engines was time
consuming and expensive. Yenko approached Chevrolet about a
special production run of 427 Camaros, using the 425HP L72
iron block engine.
An agreement was reached for COPO 9561. With the exception
of the engine, ignition system, and front springs, COPO 9561
is identical to 9560. In contrast to the ZL-1s, COPO 9561
was a steal at $489.75. This included the L72 427/425 hp
engine, special ducted hood, heavy-duty cooling, and the
special 4.10 'BE' axle. Power front discs and an optional
transmission were mandatory, but the 9561 Camaro actually
listed for around $130 less than a 396/375 hp Camaro SS.
Other dealers learned of the COPO and also ordered cars
similarly equipped. The L72 COPO cars sold well initially but insurance
companies caught on and these also became a tough sell.
Yenko reportedly canceled orders for hundreds of cars. Some
dealers really jumped on the COPO bandwagon, stocking COPO 9561 Camaros
and Chevelles. Some of more noteworthy:
# VIN Color Transmission Ordering Dealer -- ------------- --------------- ------------ --------------------- 1. 124379N569358 Dusk blue automatic Gibb-Illinois 2. 124379N569359 Dusk blue automatic Gibb-Illinois 4. 124379N608214 Cortez silver automatic Gibb-Illinois 5. 124379N608381 Dusk blue automatic Gibb-Illinois 6. 124379N608536 Cortez silver automatic Gibb-Illinois 7. 124379N608613 Hugger orange automatic Gibb-Illinois 8. 124379N608761 Cortez silver automatic Gibb-Illinois 9. 124379N608879 Cortez silver automatic Gibb-Illinois 10. 124379N608969 Dusk blue automatic Gibb-Illinois 11. 124379N609016 Cortez silver 4-speed Gibb-Illinois 12. 124379N608149 Dusk blue 4-speed Gibb-Illinois 13. 124379N609171 Cortez silver 4-speed Gibb-Illinois 14. 124379N609238 Le Mans blue 4-speed Gibb-Illinois 15. 124379N609372 Cortez silver 4-speed Gibb-Illinois 16. 124379N609395 Hugger orange 4-speed Gibb-Illinois 17. 124379N609462 Cortez silver 4-speed Gibb-Illinois 18. 124379N609510 Dusk blue 4-speed Gibb-Illinois 19. 124379N609530 Dusk blue 4-speed Gibb-Illinois 20. 124379N609599 Cortez silver 4-speed Gibb-Illinois 21. 124379N609651 Dusk blue 4-speed Gibb-Illinois 22. 124379N609690 Cortez silver 4-speed Gibb-Illinois 23. 124379N609747 Dusk blue 4-speed Gibb-Illinois 24. 124379N609838 Dusk blue 4-speed Gibb-Illinois 25. 124379N609856 Hugger orange automatic Gibb-Illinois 26. 124379N609880 Hugger orange 4-speed Gibb-Illinois 27. 124379N609965 Fathom green automatic Gibb-Illinois 28. 124379N610014 Hugger orange 4-speed Gibb-Illinois 29. 124379N610123 Hugger orange 4-speed Gibb-Illinois 30. 124379N610168 Hugger orange 4-speed Gibb-Illinois 31. 124379N610413 Hugger orange automatic Gibb-Illinois 32. 124379N610515 Hugger orange automatic Gibb-Illinois 33. 124379N610732 Hugger orange 4-speed Gibb-Illinois 34. 124379N610899 Fathom green 4-speed Gibb-Illinois 35. 124379N612763 Fathom green 4-speed Gibb-Illinois 36. 124379N612913 Fathom green 4-speed Gibb-Illinois 37. 124379N612963 Fathom green 4-speed Gibb-Illinois 38. 124379N613633 Fathom green automatic Gibb-Illinois 39. 124379N613787 Fathom green automatic Gibb-Illinois 40. 124379N615198 Fathom green 4-speed Gibb-Illinois 41. 124379N615229 Le Mans blue 4-speed Gibb-Illinois 42. 124379N615242 Le Mans blue 4-speed Gibb-Illinois 43. 124379N615362 Le Mans blue 4-speed Gibb-Illinois 44. 124379N618396 Fathom green 4-speed Gibb-Illinois 45. 124379N618522 Fathom green automatic Gibb-Illinois 46. 124379N618562 Le Mans blue 4-speed Gibb-Illinois 47. 124379N618713 Le Mans blue automatic Gibb-Illinois 48. 124379N618902 Le Mans blue 4-speed Gibb-Illinois 49. 124379N619976 Le Mans blue automatic Gibb-Illinois 50. 124379N620498 Le Mans blue automatic Gibb-Illinois 52. 124379N620934 Le Mans blue automatic Gibb-Illinois |
# VIN Color Transmission Ordering Dealer
-- ------------- --------------- ------------ ---------------------
3. 124379N608193 Daytona yellow 4-speed Berger-Michigan
51. 124379N620923 Dover white 4-speed Brooks-Georgia
53. 124379N634918 Dover white 4-speed Lyle-Ohio
54. 124379N635720 Le Mans blue / automatic Bristol Motors-Canada
black vinyl roof
55. 124379N641266 Le Mans blue / 4-speed Whit-Arkansas
parchment vinyl roof
56. 124379N641310 Dover white 4-speed Lowe-Maryland
57. 124379N642468 Daytona yellow 4-speed Brewers-Kentucky
58. 124379N642835 Garnet red 4-speed Indian River-Florida
59. 124379N642876 Hugger orange 4-speed Hechler-Virginia
60. 124379N642903 Fathom green 4-speed Scuncio-Rhode Island
61. 124379N642927 Dover White 4-speed Seltzer-Oklahoma
62. 124379N642934 Garnet red 4-speed Hechler-Virginia
63. 124379N643047 Hugger orange 4-speed Burt-Colorado
64. 124379N643171 Hugger orange automatic Indian River-Florida
65. 124379N643779 Fathom green 4-speed Lavery-Ohio
66. 124379N644311 Cortez silver 4-speed Huffmans-Illinois
67. 124379N644314 Hugger orange 4-speed Huffmans-Illinois
68. 124379N650643 Cortez silver 4-speed Harris-Indiana
69. 124379N650977 Hugger orange 4-speed Huebner-Ohio
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