Steve's Camaro Parts - Identifying a First Generation Z28

The Chevy Camaro Z28 was produced in the following years '67-'74, '77-'88, ('88-'90 IROC), '91-'02. The only true years a Z28 was not available in any form or fashion was 1975 and 1976. Basically, the Z28 option was a performance package with some nice looks added to help identify them before you got to see their tail lights. Since the Z28 was a performance package, the engine is one of the most important parts of a Z28 Camaro. In most cases the original Z28 engine is required to identify the car as possibly being a true Z28. Also, remember that having the original engine doesn't mean the rest of the car is still original. Check everything including dates, castings and partial VIN's. If the complete VIN says it was originally a 6 cylinder Camaro then you can guarantee it was not a Z28 so be sure to check the VIN. Unfortunately, these days it is so easy to fake almost everything on a Camaro - the more you know the better off you will be. Here is a good old saying that is never more true than for this ... if we had a nickel for every time someone said they had a Z28 Camaro (but did not) we would be filthy rich by now.

Identifying a First Generation Z28:
The best place to start to try to verify a first gen Z28 is by checking the engine codes and dates. We hope more people read this before buying a Camaro not after buying that so called Z28. All had a 302 cubic inch engine with a suffix code MO or MP in '67, MI or MO in '68 and DZ in '69. To get the 302 engine Chevy took a 283 crank and put it in a 327 block. Some people say Chevy put the crank in a 350 block but since 1967 was the first year for 350's and 302's and both used the 327 block it is better to say they used a 327 block. A 302, 327 and 350 block are exactly the same except for the number of main bolts which would depend on the application and the year. The 1969 302's had 4 bolt mains. The 1967 and 1968 302's did not have 4 bolt mains. They were in fact 2 bolt main blocks used in '67 and '68 302's. In 1967 they are small journal blocks and in '68 and '69 they went to large journals. The reason for the Z28 was to compete in SCCA Trans-Am Challenge Series. The engine requirements to race in SCCA was limited to 305 cubic inches. All had 4 speed Muncie manual transmissions. All had power front disc brakes at least. All had 12 bolt rear ends but didn't have to be posi. None had A/C. None were factory convertibles except one beautiful '68 Z28 was a convertible which was made for the head of Chevrolet at the time (Pete Estes) and if you own it email us a picture and all the info you can please! Just remember badges do not a Camaro Z28 make. There is NO code in the VIN that recognizes a Z28 in any first generation Camaros. Late '69 Camaros had an "X" code on the trim tag though. A Protect-o-plate can be helpful in identifying a first gen. Z28 but be careful because there are places that make reproductions of both trim tag and protect-o-plate. Before emailing us in the hopes that we know some secret to identifying Z28's check the engine codes given below. If the Camaro doesn't have the original engine then finding out whether it was a Z28 at one time just got that much harder and in most cases impossible.

Year	Trim Tag Code?	Check Engine Code Table or get Help	VIN Engine Code?
1967	YES	MO or MP	NONE
1968	NONE	MI or MO	NONE
1969	Some X codes	DZ	NONE

Common things most people erroneously think makes a First Gen Camaro a Z28 and we get asked about all the time. Also known as FAQ's on Z28 Camaros being a true Z28.

Option	Required for a Z28	Available on base Camaros	Easily Purchased and Added
Special Engine	Yes (see above)	No	NO! Very hard to fake especially the casting number and casting date
Z28 Emblems	Yes (some were "302" and some were "Z28")	No	Very much YES!
Stripes	Yes	No	Yes!
Special Hood	Not all but most	No	Yes!
Front disc brakes	Yes (Brakes could NOT be front drum brakes)	Yes - but most got drum brakes.	Yes! Check that they are not after market though.
Special Instruments - Amp, temp, oil pressure, fuel, clock, tach	No - that's right NO not required.	Yes - just required V8 and Console	Yes! They were AC gauges. Also tach's were dealer installed or factory late in 69.
12 bolt rear end	Yes but didn't have to be a posi	Yes - but check dates of rear end	Not easy to find one dated for a specific Camaro build date.
Automatic (ANY)	NO! Automatic was not available on any first gen Z28	Yes	Easy to change to 4 speed but not easy to fake correct 4 speed trans with partial VIN. Also be sure to check manual transmission. The Z28 Trans was not a Saginaw it was a Muncie. Saginaw was the "low" performance manual trans.
"X33" or "X77" Code on trim tag on 1969's only	Yes but for late style Norwood assembled '69 Camaros only! (No so called "X" codes on Van Nuys assembled Camaros)	No - Base Camaros got "X11"	Not easily added but check VIN to make sure it was a V8 because trim tags are getting swapped out. Also have seen people selling reproduced trim tags so watch out.

Source: www.chevy-camaro.com

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Steves Camaro Parts -1967 - 1968 - 1969 What our Customers Say

Skraper D. - San Francisco

I love this place. Its the one stop shop for all my 68 camaro needs. Staff is friendly and always helpful. Great literature and great customer service. I highly recommend this place for all your first generation muscle car needs.

Michael M. Pacifica

Steve is the man, the best in the business! He has been doing it the longest and if he doesn't have it he knows where to get it if you need it...Good guy!!

Henry B.  San Francisco

great service for the parts you need for your vintage camaro. i bought a cowl induction hood by goodmark for a deal!

i don't order from the mail order places because a) they give you cheap stuff, b) its not that much cheaper with the shipping and handling, and c) nothing can replace good ol' fashioned customer service.

Randy San Mateo

Just the Best Automotive Shop hands down. It is nice to have one so passionate like Steve. You can't get better service anywhere

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Steve's Camaro - Is my Camaro an SS?

The Chevy Camaro Super Sport, better known as the SS, was produced from '67-'72 and '96-2002. Basically, it was a performance package with some nice looks added to help identify them before you got to see their tail lights. Since the SS was a performance package, the engine is one of the most important parts of an SS Camaro. In most cases the original SS engine is required to identify the car as possibly being a true SS. Also, remember that having the original engine doesn't mean the rest of the car is still original. Check everything including dates, castings and partial VIN's. If the complete VIN says it was originally a 6 cylinder Camaro then you can guarantee it was not an SS so be sure to check the VIN. Unfortunately, these days it is so easy to fake almost everything on a Camaro - the more you know the better off you will be. Here is a good old saying that is never more true than for this ... if we had a nickel for every time someone said they had an SS Camaro (but did not) we would be filthy rich by now.

Identifying a First Generation SS:
From the looks of the emails we get on this subject we can sum it up by saying the best place to start to try to verify a first gen SS is by checking the engine codes and dates. We hope more people read this before buying a Camaro not after buying that so called SS. The standard engine in a '67 to '69 SS was a 350/295hp (300hp in '69). A big block 396 with either 325hp ('67-'69), 350hp ('68-'69) and 375hp ('67-'69). A first gen. SS either had a 350 or a 396 engine. Required power front disc brakes starting in '69. A 10 or a 12 bolt could be ordered with an SS. A/C was available on SS's unless the engine was 396/375hp. All first gen SS's could be ordered as a convertible.
There is NO code in the VIN that recognizes an SS in any first generation Camaro. A '67 Camaro has a code on the trim tag for an SS and a late '69 Camaro had an "X" code on the trim tag to identify some SS's. The X11 code is the only exception to identifying a true '69 SS Camaro because the code also means a plain Camaro. Unfortunately there are no codes on a '68 Camaro to help identify an SS. A Protect-o-plate can be helpful in identifying a first gen. SS but be careful because there are places that make reproductions of both trim tag and protect-o-plate.
The engine is very important to an SS Camaro but is necessary to identify all '68 and most '69 Camaros. Before emailing us in the hopes that we know some secret to identifying SS's check the engine codes at Engine Codes for SS horse power (HP) ratings see below. If the Camaro doesn't have the original engine then finding out whether it was an SS at one time just got that much harder and in most cases impossible. The only thing you can for sure determine, if your first gen doesn't have the original engine and doesn't have any documentation to help, is that your Camaro was not an SS. Before you start searching and asking questions be sure you want to know the answer. However, even if a first gen has everything that an SS had but doesn't have the original engine you can still not be sure it was originally an SS - see below for more on this.

Year	Trim Tag Code?	Check Engine Code HP get Help	VIN Engine Code?
1967	YES	350-295hp or 396-325hp, 375hp	NONE
1968	NONE	350-295hp or 396-325hp, 350hp, 375hp	NONE
1969	Some X codes	350-300hp or 396-325hp, 350hp, 375hp	NONE

Common things most people erroneously think makes a First Gen Camaro an SS and we get asked about all the time. Also known as FAQ's on SS Camaros being a true SS.

Option	Required for an SS	Available on base Camaros	Easily Purchased and Added
Special Engine	Yes (see above if not in list then not an SS engine!)	No	NO! Very hard to fake especially the casting number and casting date but engine code can be restamped so watch out!
SS Emblems	Yes	No	Very much YES!
Stripes	Yes	No	Yes!
Special Hood	Yes	No	Yes!
Front disc brakes	Yes on 1969's only '67 and '68 SS's could get drum drakes (Special front drum brakes in '67 were RPO J65 and SS only)	Yes - but most got drum brakes. Drum drakes did not require power assist. Disc brakes in '68 and '69 did.	Yes! Check that they are not after market though but applies to '69 Camaros only anyway. Basically brakes on Camaros should not be used as a determining factor of an original SS or not. Disc brakes in '68 and '69 required power assist (J50).
Special Instruments - Amp, temp, oil pressure, fuel, clock, tach	No - that's right NO not required.	Yes - just required V8 and Console	Yes! They were AC gauges. Also tach's were dealer installed or factory late in 69.
2 speed power glide Automatic	The 2 speed power glide automatic was not available on big block Camaros	Yes	Easy to change to another automatic but not easy to fake correct transmission with partial VIN.
12 bolt rear end	No but in '69 and on L48 only the rest was 12 bolt required.	Yes - but check dates of rear end	Not easy to find one dated for a specific Camaro build date but should not be used as a determining factor to identify an original SS if Camaro has a 12 bolt.
"X11" on trim tag on 1969's only	350 SS only but a big NO for a big block SS	YES! not all "X11's" were SS's. Check the engine. If not original then assume the "X11" was for a base Camaro.	Not easily added but check VIN to make sure it was a V8 because trim tags are getting swapped out. Also have seen people selling reproduced trim tags so watch out.
Myth buster - 327 SS Camaro	NO 327 SS Camaros and I've heard it all but NO sorry didn't happen!	Yes base Camaros ONLY!	Unfortunately these can be very easily restamped into a 350 SS code. A 327 has the same casting number as a 350 so watch out.

Source: www.chevy-camaro.com

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Steve's Camaro - Window Felts are Back in Stock

WINDOW FELTS ARE BACK IN STOCK

Have you been waiting forever to find the correct orginal type clips to mount the 1968 rally sport body side moldings? Your search can now end. This clip set has all the correct mouting to attach the 6 rally sport moldings to your Camaro.

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Steve's Camaro Parts - 1969 Chevy Camaro Z28

Classic Muscle Cars Image Gallery

A cowl-induction hood was standard on the 1969 Chevrolet Camaro Z28. The available Rally Sport package concealed the headlights behind hinged doors.

It wasn't the fastest muscle car, but with single-season styling and a unique combination of brake, engine, exhaust, and induction options, the 1969 Chevrolet Camaro Z28 was arguably the most desirable Z28 of all.

Adding $458 to the $2,726 base price of a Camaro coupe, RPO Z28 included the F41 handling suspension with E70X15 raised-letter tires on seven-inch wide rims, quicker steering, and twin rally stripes. Front disc brakes were standard on the 1969 Chevrolet Camaro Z28, and for the first time, four-wheel discs were offered. They cost $500 and just 206 sets were delivered, about half going to full race cars.

The solid-lifter 302-cid V-8 with an 850-cfm four-barrel carburetor was again exclusive to the Z28. Dynomometer tests at close to 400 horsepower made a joke of its 290-horsepower rating. Dealer-installed dual four-barrel carburetor options were offered even in '67, and for '69, $500 bought twin 600-cfm Holleys on a cross-ram manifold, though at no change to the 290-horsepower rating. Chambered exhaust pipes -- perhaps the least-restrictive exhausts Chevy ever offered -- also were available.

The solid-lifter 302-cid V-8 with an 850-cfm four-barrel carb was a Z28 exclusive.

Yet another functional option unique to 1969 Chevrolet Camaro Z28s was the $79 cowl-induction hood. It had a valve that snapped open at 80-percent throttle to draw in cool air from the base of the windshield.

1969 Chevrolet Camaro Z28s again came only with a Hurst-shifted close-ratio four-speed; 3.73:1 gears were standard, with up to 4.10:1 gears available. Positraction was an option. Styling could be enhanced by the Rally Sport package, which gained transparent louvers for its hidden-headlamp covers.

Handling was razor-sharp, aided by power steering that was both quick and had road feel. Four-barrel 1969 Chevrolet Camaro Z28s could run the quarter mile in 14.8 seconds at 101 mph, but the small-block's shortage of low-end torque was multiplied with the dual-quads, which fed on sky-high revs. Even dropping the clutch at 4000 rpm produced stumble off the line.

As Trans Am titles in 1968 and '69 showed, the Z28 was a road-racer first, a street machine second. Drivers who understood its bare-knuckle character bought 7,199 of them for '68, and sales nearly tripled for the 1969 Chevrolet Camaro Z28 -- a record that would stand until 1978.

Its road-racing roots were evident in a peaky engine that was ill-at-ease on the street, but the Z28 was one of the best-handling rides of the muscle car era.

The '69 Z28 was one of the hottest-looking rides of the classic muscle car era, and showed what Chevy stylists could do to express performance and excitement. For additional photos of '69 Z28s, and a special look back at a fascinating selection of vintage Camaro brochures, explore the next three pages in this article.

.

• Chevy muscle cars beat at the heart of big-cube high performance. See profiles, photos, and specifications of Chevy muscle cars.

The 1969 Chevrolet Camaro Z28

Specifications

Wheelbase, inches: 108.1
Weight, lbs: 3,765
Number built: 20,302
Base price: $3,185
Top Available Engine
Type: ohv V-8
Displacement, cid: 302
Fuel system: 2 x 4 bbl.
Compression ratio: 11.0:1
Horsepower @ rpm: 290 @ 5800
Torque @ rpm: 290 @ 4200
Representative Performance
0-60 mph, sec: 7.4
1/4 mile, sec @ mph: 15.12 @ 94.8

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source: musclecars.howstuffworks.com/classic
by the Auto Editors of Consumer Guide

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Steve's Camaro Parts - Here's a peek behind the scenes, inside Chevrolet Engineering

Here's a peek behind the scenes, inside Chevrolet Engineering during a time when the stakes were high and winning was everything...

The end result: Two consecutive Trans-Am championships and one of the most potent small block power packages ever produced!!!

By Wayne D. Guinn

Yes!... Amazing but true, once you've seen a Cross Ram intake manifold set up in an early Camaro engine compartment, you can't help from being affected. Sometimes to the extent that it initiates the bizarre (but extremely enjoyable) obsession defined above.
Most Camaro enthusiasts will readily admit that one of their favorite topics of discussion at Camaro gatherings is the cross ram induction system and how those cars equipped always get the draw...! And why not? Aesthetically, the Cross Ram is awesome, the symmetry and proportion of the design is strikingly beautiful, especially with the massive chrome topped air cleaner gleaming in place. And function?... In terms of performance, the special induction system has demonstrated itself to be capable of helping produce an amazing 458 HP from the 302 @ 7200 RPM..!
In fact... its sole purpose was to coax huge amounts of horsepower from the relatively small 302 CID engine in the upper rpm range without severely compromising low end power. And... if that wasn't a tall enough order, it had to do so under the severe restriction of "keeping it in its pants" or.. more accurately, under the hood due a safety rule imposed by the SCCA race sanctioning committee.
As it turns out, not only was Chevrolet able to accomplish all of the above, but they far exceeded all expectations and realized tremendous success doing so. Today, we recognize the legendary Cross Ram Intake system as being one of the largest contributing factors responsible for helping establish the Camaro as the 1968-1969 TRANS-AM champion.

IT ALL BEGAN WITH THE NEED FOR...

SPEED!

Coming onto the scene a few years behind the Mustang, the Camaro needed to play a hard and fast game of catch up...
Chevrolet would have to compete hard to capture some sales from the "Pony Car" market that the Ford Mustang created. So, when it came time to get competitive, Chevrolet got serious-both at the consumer level and at the race track.
Chevrolets plan was simple... Their competitive formula was based on the theory that a winning image sells- and it was through racing that Chevrolet successfully promoted the Camaro and tapped into the fast growing youth market. To create that image, Chevrolet put together the Camaro Z/28 package to compete against their biggest rival, the Ford Mustang in the Sports Car Club of America's (SCCA) Trans-Am road racing series, better known as "the battle ground".

The Camaro's first year in competition was hard fought with a 302 single four barrel induction system. This was the limit established by the SCCA sanctioning body in order to keep speed at a reasonable rate for safety considerations. However, as the popularity of the series increased, all caution went with the wind and for the 1968 Trans-Am racing season, the SCCA changed the rules from "Not more than one four barrel" to "Not more than two four barrels". This change came largely in response to unofficial factory prodding with the intention of creating a "More exciting Trans-Am series".
The other manufacturers were ready and so was Chevrolet. They released for use with the 302 cuin engine the "2X4 CARBURETOR CONVERSION UNIT" PN #3940077. The special "Cross Ram Induction" system was made available over the counter through Chevrolet parts departments as a "Heavy Duty Service" option beginning December 1967. Although somewhat ambiguous, the term "heavy duty service", is Chevrolet's frequently used catch all phrase meaning- "intended for racing".
The release of this special racing equipment marked the begining of an incredible winning streak for the Camaro on the track and for Chevrolet in terms of sales.

AND NOW, the nuts and bolts of it...

SYSTEM DESIGN...

The system consists of a special two piece manifold, carburetors and related hardware needed for installation. The inlet manifold assembly is a cast aluminum single plenum "Cross Ram" type with provisions for two four barrel carburetors.

To the right is the Cross Ram System as it came through your local Chevrolet Parts Department...

By 1967, the Cross Ram concept was by no means new, Chrysler engineers had developed the "RAM" idea in the early '60's. Equal long tuned runners create a ram effect needed to "pack in" the fuel mixture when using long duration cams on engines with high rpm capabilities.

above: Chrysler pioneered the use of the long- runner cross-ram intakes on thier early '60s 300s as shown above...

The Chevrolet Cross Ram design was intentionally kept low by placing the carburetors "outboard" specifically for hood clearance. The vertical tunnel ram is more efficient but it obstructs vision in road racing, for this reason the SCCA and NASCAR rules required the manifold and carburetors to fit under a stock hood.

Cold air induction drawn through the cowl area was then adapted to further enhance the 2X4 system. Once again this was nothing new, it was done before in '63 on the Chevrolet Z11 stock cars in the NASCAR circuit. The high pressure area at the base of the windshield is utilized to enhance the ram effect by allowing the carburetors to draw fresh cool air which creates a denser fuel charge thereby increasing volumetric efficiency and horsepower. Names synonymous with the system are: COLD AIR INDUCTION, FRESH AIR INDUCTION and COWL INDUCTION.
The offset carburetor configuration makes it possible to use Holley carburetors with full metering bodies, allowing easy jet changes for fine tuning, and center pivot float bowls needed to prevent flooding during hard acceleration and cornering.
Although the manifold plenum chamber below the carburetors is large, its size was kept minimal by its designers to retain good low end response. The runner length was tuned specifically for use with the 302 cuin engine to produce peak horsepower at 7,200 rpm using the optional "140" cam and tuned headers. The full racing version of the 302/cross ram engine has an actual power curve that is somewhat narrow and requires optimum use of gearing to maintain rpm in the power range (4200-7200 RPM).
Chevrolet initially specified carburetor #3941140, Holley list #3810S, which featured a 585 cfm rating, dual feed and sliding cam actuated secondaries. Response problems led them to change to carburetor #3942595, Holley list #4210A which featured a 600 cfm rating, dual feed, sliding cam actuated secondaries with a different opening rate. Once again, response problems led to the third and final change which cured the problem. Carburetor #3957859, Holley list #4295, rated at 600 cfm, dual feed, sliding cam actuated secondaries and dual accelerator pumps did the trick.
Because of the relatively large plenum area below the carburetors, accelerator pumps on primaries and secondaries are necessary to adequately richen the mixture during acceleration to prevent an excessively lean fuel mixture condition which causes bogging, power loss and ultimately burnt valves.
For optimum tuning the front carburetors primaries face forward and the rear carburetors primaries face rearward. There are no provisions for manifold heat or chokes on the carburetors, which is typical of a race only induction system.
Winters Foundry, who has done almost all of Chevrolets aluminum casting, also produced the cross ram units. Development of the Cross Ram was a collective effort on the part of many talented individuals inside and outside of Chevrolet engineering including Smokey Yunick who performed test evaluations and some "hands on" development.
After initial development was complete, the prototype castings were test evaluated on the engine dynamometer. Studies revealed "distribution fixes" were needed to prevent wet fuel travel. Chevrolet specified a few additional changes over the initial prototype units which included the relocation of the vacuum take off, from the bottom half of the manifold to the upper top plate, to eliminate the possibility of wet fuel entering the vacuum lines and to gain a more direct route for plumbing. Provisions for heater hoses were also added to facilitate the newer water pump design and hose routing scheduled for use on the 1969 models.

The concept and development...

According to engineer Bill Howell, the concept for the small block Cross Ram evolved from an experimental tuned, long crossing runner, multi-carbureted manifold, that was developed in latter part of '66 for the big block Mark IV engine. Coincidentally, the lobe profile for the "140" off road cam which was developed for use in conjunction with the Cross Ram, was also derived from the big block. Initial design work for the small block Cross Ram began approximately mid year '67 with a target date for completion in December in order to be homologated into the SCCA recognition forms in time for the start of the '68 Trans-Am.
Jerry Thompson, a key development engineer, took the concept above and developed a test manifold using a Corvette fuel injection bed plate. They epoxied in eight tubing runners to which they attached a plenum box fabricated from sheet metal and fitted a top plate that would accommodate two 600 cfm carburetors. Essentially, it was a vertical ram manifold. When it was set up on a developmental test engine the dynamometer results showed an approximate 25.5 horsepower increase over a base run using the same engine with the manifold/carburetor system used on the '67 Trans-Am engines. This first crude adaption set the basic specifications for the cross ram that was to follow.
The results of that test manifold were exactly what they were after. The problem however was how to keep runner length long for the ram effect, maintain the plenum box on which the carburetors sat, and somehow keep it all under the hood. The solution along with the initial design specifications were drawn up inside the drafting room by Design engineer Charley Turner. He was able to keep the manifold height at a minimum and runner length long by laying the runners down, crossing them horizontally side to side and then enclosing them by building the plenum box around them. Top and side wall design as well as carburetor and linkage details were sorted out by design engineer Chris Madson, followed by the laying up of cores and creation of plugs at Winters Foundry. After the actual castings were produced at the foundry, they were sent to Chevrolet Engineering and Smokey Yunicks garage for evaluation. They found out immediately that the manifolds needed further refinement specifically in the area of fuel distribution. Essentially, the problem was that the massive plenum area of the manifold centrifuged the fuel mixture causing it to separate into it's two constituent components leaning out the mixture markedly and causing wet fuel distribution on the sides and bottom of the manifold. As a result of those findings several revisions were made, the most important were being the fuel distribution fixes.

Project Engineer Jerry Thompson explains...

"The first unit would hardly run the mixture was so bad. We ran air flow tests and found it really did pump the air. Using distribution fixes we tweaked it into a reasonable power band and tried a collection of carbs. The 600 cfm's seemed adequate, larger carbs just ate up the torque so we stuck with the 600's.
At this point, Rodger Penske and Mark Donohue stopped by Engineering for a demonstration, Mark went nuts (9/16" wrench in hand) to get the unit to use. We weren't quite done calibrating at the time so we held them off. As soon as we had the calibration complete we had the foundry change the molds and sent the prototype off to Traco Engineering (builders of Penske's engines). The production people went on to dot the eyes and cross the tees as they do and the race cars got the pieces they needed."
Initially there were four or five "working prototype" manifolds that circulated back and forth between Smokey's shop and Howell's group. One of the earlier prototype castings.
(10-27-67), was installed on the Chevrolet built '68 Camaro Z/28 test vehicle that was used by Chevrolet Engineering for test evaluation of the HD equipment. This car also doubled as a press car and was featured in many magazine articles (SEE HOT ROD MAY '68) displaying the HD options for the '68 Z/28.

With the top off the manifold, the fuel distribution runners that were added to the prototype can be clearly seen. These were necessary to prevent cylinder to cylinder mixture differences. The confgureation seen here is the final production arraingment. Aluminum wire and epoxy were used to build the "dams" on this prototype manifold, ahile the production versions were cast in at the foundry.

While evaluation continued on the test vehicle, further developmental work was being carried out in engineering where the final configuration for the distribution fixes was made. Because not much work was done at that time with flow bench technology, the distribution fixes were accomplished basically by gas analyzation methods, obtaining readings by taking samples at the exhaust ports. Also utilized was the more gross method of "reading the plugs" after dyno runs following changes that were made based on educated guess work. According to Jerry, this particular area of development is quite involved. An intake port that is rich at low rpm can also demonstrate itself to be lean at high rpm. Needless to say, time spent in this area is crucial for the best obtainable performance results. When all involved were satisfied with the flow characteristics and the developmental stage of the prototype test unit, it was blessed by Vince Piggins and personally hand delivered to Tracos shop by Engineer Bill Howell.

Once there it would then be set up on the engine which was being prepared for Penske's '68 Trans-Am clinching number 6 Camaro for the beginning of the rapidly approaching 1968 season. Immediately following, specifications with revisions were drawn up for the production version and manufacturing soon followed.
One of the most remarkable aspects concerning the development of this special equipment is that the actual factory prototype units were used on Penskes race cars long before they became production pieces, making it truly a product of race bred technology.


A special note of interest concerning the early factory press release photographs depicting the carburetors with milled air horns. According to Jim Travers of Traco Engineering, he accompanied the Penske crew to the first race in which the Camaro used the Cross Ram manifold system. They began experiencing some problems related to the induction system, using a pair of Dutchmans (tin snips) Jim cut off the air horns and filed them smooth relieving some of the problem, "Those first carburetors just wouldn't run right otherwise".
As it turns out, the problem wasn't so much the fault of the carburetor as it was with the first design air cleaner. Being the element was only 1 1/2 inches tall, it bought the air cleaner lid so close to the carburetor air horn, it restricted and upset flow to the primaries. The height restriction forced air to flow horizontally and then make an acute turn down into the primary. This sharp turning of air caused turbulence and upset proper fuel regulation within the metering bodies. Cutting off the air horns smoothed out the flow and compensated for some of the restriction.
The air horns function is to facilitate the choke mechanism which on these carburetors is absent, not even the holes for the choke butterfly shaft is drilled by Holley. Therefore, there is no need for the horn to remain and it is beneficial to remove it for the sake of better flow. The problem is not as critical with the second design air cleaner with the taller element, the additional height of the element allows a more adequate, less restricted flow however, for competition this modification serves a distinct advantage. Beyond the air horn the only other modification Traco Engineering performed on the cross ram units was to stagger jet the carburetors for a more even fuel mixture.
After the Traco prepared engines were installed in the Penske cars they found that the production fuel lines developed for the Cross ram unit began to present a problem during jet changes. The rigid steel lines and fuel distribution block all tie together on the inside of the manifold between the two carburetors, making access for maintenance/alterations difficult and time consuming. According to Bill Howell they took the carburetor float bowls and switched them end to end which puts the fuel lines on the outside of the manifold, effectively getting them out of the way of the throttle linkage. Then by utilizing flexible aeroequip fuel lines, they were afforded the convenience of quick and easy jet changes and float adjustments without disconnecting the fuel lines.
The oil splash shield seen on the bottom of portion the prototype Cross Ram unit was developed for testing. It was evaluated and dropped never making production due to it's inability to demonstrate effectiveness during testing. The small block does not have a problem of excessive amounts of oil thrown around in that area as is common with the large block. The bottom of the manifold, which are actually the intake runners, sits quite high and the small amount of oil splash that does reach there does not significantly heat the manifold.

Lou Faux, Chevrolet engineer in charge of cooling and lubrication development on the 302 engine explains...

"On the production vehicle the actual function of the manifold oil shield is to prevent oil from coming in contact with the extreme heat of the manifold heat cross over. The inclusion of which is necessary for good cold weather drivability. Any oil that would come in direct contact with that super heated area would carburize, denaturing the oil and cause "clinkers" to form and drop down into the engine case. Since there is no manifold heat cross over used on the Cross Ram manifold, there is no need for a shield of that type".

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source: www.camaro-untoldsecrets.com

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