1984 Corvette -

[EPA2]

Originally Posted by prowlerjc

Remeber Hot Rod Magazine even made a project car called Z26.

I recall Chevy came pretty close to putting the 2.8 V6 in the Chevette about the same time. I heard it got so close to production that part numbers were released for the engine mounts, etc.

Would have been a cool ride.

I don't remember Hot Rod's V6 Camaro. What V6 motor was in it? That sounded like a fun project car.

Speaking of Hot Rod project cars do you remember the 2.8 H.O. V6 powered Chevette that they built as a project back around 1982? That was one little road rocket.

It is a pity that Chevy did not put the 2.8 V6 in the Chevette, as light as that car was it would have really moved especially with the 2.8 H.O. (135 horsepower).

[prowlerjc]

Originally Posted by EPA2

I don't remember Hot Rod's V6 Camaro. What V6 motor was in it? That sounded like a fun project car.

It was the base 2.8. They basically put all the Z28 styling and suspension bits on a base car.

[EPA2]

Originally Posted by prowlerjc

It was the base 2.8. They basically put all the Z28 styling and suspension bits on a base car.

Do you remember this Camaro Concept car called the Camaro GTZ? The GTZ was powered by a fuel injected 4.3 liter V6 as I recall. Chevy was advertising it as the future 1988 high performance V6 Camaro if they decided to phase out the V8. Here it is shown on the front cover of a 1985 issue of Motor Trend:

[prowlerjc]

Vaguely remember that, but seeing that cover reminds me of how close Chrysler came to bringing over that Renault Alpine.

[2002 Caddy]

Originally Posted by EPA2

Just out of curiosity, when you rebuilt your electronic quadrajet did it still have the factory plugs blocking the idle air mixture screws? These usually got punched out when the first adjustment of these screws occurred which was usually by 50,000 miles. If the plugs were gone then your carb has had adjustments done to it. However 200,000 miles on the original carb before a rebuild is pretty darn good.

That's great that you'll be passing your '83 Z28 to your son or daughter. That's how I got my 1982 T/A, my dad bought it new and gave it to me several years ago.

The plugs were intact... I removed them to rebuilt the unit... My 87 442 (which also got a rebuild, by me at, around 150,000 miles ) also had the plugs intact... The Camaro needed the rebuild mostly because the small copper tubes that "dip" from the air horn into the bowl had become loose and had fallen out... (mostly due to my "dukes of hazard" attempts over train crossings... yes, I have gotten all 4 wheels of that car in the air at once... and the big dent in the oil plan proves it)... On the 87 the TPS wires had become so old and brittle that they had just shorted out... No adjustments to the carb were needed... clean it out, set the float, set the TPS and it was done.

On the 83 I did a full rebuild and drilled out the plugs on the 87 I left them intact an just cleaned the openings with carb spray...

Both cars are still on the factory O2 sensor and both cars pass (and have always passed) tail pipe smog checks with stock like CO, HC and NOx numbers.

If a dealer talked you into adjusting the mixture screws at 50,000 miles I would find another dealer... This is not required, or recommended, by GM.

[EPA2]

Originally Posted by 2002 Caddy

The plugs were intact... I removed them to rebuilt the unit... My 87 442 (which also got a rebuild, by me at, around 150,000 miles ) also had the plugs intact... The Camaro needed the rebuild mostly because the small copper tubes that "dip" from the air horn into the bowl had become loose and had fallen out... (mostly due to my "dukes of hazard" attempts over train crossings... yes, I have gotten all 4 wheels of that car in the air at once... and the big dent in the oil plan proves it)... On the 87 the TPS wires had become so old and brittle that they had just shorted out... No adjustments to the carb were needed... clean it out, set the float, set the TPS and it was done.

On the 83 I did a full rebuild and drilled out the plugs on the 87 I left them intact an just cleaned the openings with carb spray...

Both cars are still on the factory O2 sensor and both cars pass (and have always passed) tail pipe smog checks with stock like CO, HC and NOx numbers.

If a dealer talked you into adjusting the mixture screws at 50,000 miles I would find another dealer... This is not required, or recommended, by GM.

Wow that's great life out of the stock O2 sensors usually after 85,000 miles most are ready for the trash bin.

I have rebuilt some quadrajets the last few years and gone through my share of cores that I picked up for other people. I noticed that on most cars with the 1979 on up quadrajets (the quadrajets with the plugs) with over 50,000 miles were more likely to have the plugs punched or drilled out. I did of course see some quadrajets with over 100,000 miles with the plugs still intact. I rebuilt a factory original '79 quadrajet a few years back which only had 27,000 original miles, it had the original plugs still on. I figured I would rebuild it and try it without adjusting the mixture screws (so I would not have to punch the plugs out), and the carb ran great.

Do you know what GM recommended as the standard interval you could go without adjusting the mixture screws? I know on the older quadrajets it was usually standard practice that every tune-up or idle adjustment - the idle air mixture screws were to be adjusted also.

Do you still have your 1987 442? I worked at an Olds dealership back in the summer of 1987 right before I started college, I remember the 442 oh so well. Enjoyed driving the car. To this day the 442 is my favorite 1980s 2-door G-body. As much as I love the 1987 Grand National and to lesser degree the 1987 Monte Carlo SS, I would still prefer a 1987 442. The interior was so nicely done, comfortable seats and great instrumentation. Back then Oldsmobile had a nice luxury touch to their cars. I really liked the flush mounted headlamps which were new for 1987. And the H.O. 5.0 liter (Olds 307), provided plenty of punch and had a nice exhaust tone.

[MCGARRETT]

Chevrolet made the decision. In reading all the behind the scenes, the Chevrolet engine engineers were really taken with the Cross-Fire system. They apparently had a really hot pre-production Cross-Fire 1982 Z28 with a manual transmission that was a test mule. I don't have any performance figures but apparently it was a fast car. By the time they started putting the engine through the EPA certification, the manual transmission went out the window and this is probably when the restrictions to the motor were added.

There are similar stories like this that took place at other divisions too, one of the earlier rules was that you could certify and engine in one model and then offer it as an option on another car in the line up too, or something like that, Oldsmobile engineers were playing around with the idea of sticking the big car/Trans Am 403 in the downsized Cutlass for 78 or 79(for the Hurst Olds) but it was shot down.

[2002 Caddy]

Originally Posted by EPA2

Wow that's great life out of the stock O2 sensors usually after 85,000 miles most are ready for the trash bin.

I have rebuilt some quadrajets the last few years and gone through my share of cores that I picked up for other people. I noticed that on most cars with the 1979 on up quadrajets (the quadrajets with the plugs) with over 50,000 miles were more likely to have the plugs punched or drilled out. I did of course see some quadrajets with over 100,000 miles with the plugs still intact. I rebuilt a factory original '79 quadrajet a few years back which only had 27,000 original miles, it had the original plugs still on. I figured I would rebuild it and try it without adjusting the mixture screws (so I would not have to punch the plugs out), and the carb ran great.

Do you know what GM recommended as the standard interval you could go without adjusting the mixture screws? I know on the older quadrajets it was usually standard practice that every tune-up or idle adjustment - the idle air mixture screws were to be adjusted also.

Do you still have your 1987 442? I worked at an Olds dealership back in the summer of 1987 right before I started college, I remember the 442 oh so well. Enjoyed driving the car. To this day the 442 is my favorite 1980s 2-door G-body. As much as I love the 1987 Grand National and to lesser degree the 1987 Monte Carlo SS, I would still prefer a 1987 442. The interior was so nicely done, comfortable seats and great instrumentation. Back then Oldsmobile had a nice luxury touch to their cars. I really liked the flush mounted headlamps which were new for 1987. And the H.O. 5.0 liter (Olds 307), provided plenty of punch and had a nice exhaust tone.

Yes still have both the 83 Z28 and the 442... As for Q-Jet Service interval... there was a reason that GM stuck the plugs on the mixture screws (and riveted the choke housing too for that matter) these were NEVER to be serviced as part of a tune up or what have you... The only time adjustments were to be made to the idle mixture was during a full on carb rebuild.

If you see the plugs punched out on a low mileage car, that is a 100% guarantee that somewhere in that car's life it was serviced by someone who did not understand how the CCC Q-Jet worked or what the system did. (AKA had no clue). In the GM FSM there are lots of "are you sure"... "do you really need to do this"... "maybe there is a vacuum leak somewhere" warnings about removing the rivets or plugs...

In fact the CCC Q-Jet adjusted its mixture as you drove... Hook up an old school analog dwell meter (try and find one of those anymore) to the diagnostic port in V6 mode and you can watch the car go from rich to lean as the load on the engine and engine speed changes.

The CCC system was used by GM from 1980-1990...on everything from Vettes to Station Wagons... Crossfire was a 3 year blip...on only 3 cars and only a small percentage of those. Other then looking like a dual carb 302 and those cool little doors that opened at WOT... it was a "meh" design... A "we need something fuel injected today" response...

[LeSabre]

Originally Posted by EPA2

Part of the reason has been due to Chevrolet playing it safe - being too conservative. However with all the rumblings I have heard since the new Camaro was released from Chevy fans about how the Corvette needs a new design. I think if Chevy is listening we may see a different design direction in the C7.

BTW do you have any pictures of your LeSabre? I always liked that model of the LeSabre. One of my favorites of that era LeSabre was the 1986 LeSabre Grand National:

http://www.lesabret-type.com/LeSabreGN.html

..

No, but it looks like this, though mine is maroon. It also has a (maroon/magenta)cloth top as it is a "Body by Fisher" model.
And yes, Mine still has it's hood ornament. It is something I am quite protective of as I know/understand how easily they can break & I hear its a PITA(pain in the ass) to replace them.



!!!!!

[EPA2]

Originally Posted by 2002 Caddy

Yes still have both the 83 Z28 and the 442... As for Q-Jet Service interval... there was a reason that GM stuck the plugs on the mixture screws (and riveted the choke housing too for that matter) these were NEVER to be serviced as part of a tune up or what have you... The only time adjustments were to be made to the idle mixture was during a full on carb rebuild.

If you see the plugs punched out on a low mileage car, that is a 100% guarantee that somewhere in that car's life it was serviced by someone who did not understand how the CCC Q-Jet worked or what the system did. (AKA had no clue). In the GM FSM there are lots of "are you sure"... "do you really need to do this"... "maybe there is a vacuum leak somewhere" warnings about removing the rivets or plugs...

In fact the CCC Q-Jet adjusted its mixture as you drove... Hook up an old school analog dwell meter (try and find one of those anymore) to the diagnostic port in V6 mode and you can watch the car go from rich to lean as the load on the engine and engine speed changes.

The CCC system was used by GM from 1980-1990...on everything from Vettes to Station Wagons... Crossfire was a 3 year blip...on only 3 cars and only a small percentage of those. Other then looking like a dual carb 302 and those cool little doors that opened at WOT... it was a "meh" design... A "we need something fuel injected today" response...

Just for the record some of these carbs were 1979 units and one was a 1980 which did not have a CCC, since they were non computerized quadrajets. However I pulled a 1979 Pontiac service manual and as you mentioned GM only recommeded in the the adjustment of the mixture screws when a carb overhall or rebuild is done and if there are emissions problems.

The Cross-Fire system system was indeed made to look like a showpiece. However GM did make full use of the TBI technology used on the Cross-Fire system. As I mentioned before, the same spec TBI from the dual TBI 5.0 liter Cross-Fire system was used starting in 1982 on the 2.5 liter Iron Duke and provided reliable service for millions of the different GM customers. And when GM phased out it's LG4 305 4bbl by the end of the 1987 model year it was replaced by a L03 305 V8 with a dual throat single TBI unit using the same technology as was found on the (dual single TBI) Cross-Fire motors. And the L05 (350) 5.7 TBI powered V8 was introduced in 1987 as the new flagship motor for GM's new updated pickups. This TBI proved to be a very reliable truck engine and eventually made it into other GM cars such as the Chevrolet Caprice and rear-wheel drive Cadillac Fleetwood.

The Cross-Fire system did it's job reliably and provided enough performance for the 1982 and 1984 Corvette to make it the fastest American production car at the time. For the 1982-1983 Camaro Z28 and Trans Am, the 5.0 liter Cross-Fire allowed these cars to be among the fastest available at the time with the 1982 5.0 Cross-Fire rated at 165 horsepower (8 more than the 5.0 liter H.O. in 1982 Mustang GT) and 175 horsepower for 1983 which was on par (in relation to horsepower) with the 175 horsepower 4 bbl 5.0 liter H.O. in the 1983 Mustang GT and had 10 more horsepower than the TBI equipped 5.0 liter H.O. 1983 Mustang GT (165 horsepower).

Cross-fire also faired pretty well among the different automotive magazines back in the day, the reviews were pretty favorable. The system was reliable and it provided good performance for its day, and it put money into GM's pocket. In closing the Cross-Fire system was a success.

[EPA2]

Originally Posted by LeSabre

No, but it looks like this, though mine is maroon. It also has a (maroon/magenta)cloth top as it is a "Body by Fisher" model.
And yes, Mine still has it's hood ornament. It is something I am quite protective of as I know/understand how easily they can break & I hear its a PITA(pain in the ass) to replace them.



!!!!!

Very nice color combination!

[MCGARRETT]

No, but it looks like this, though mine is maroon. It also has a (maroon/magenta)cloth top as it is a "Body by Fisher" model.

What is a "Body by Fisher" model? As far as I know, they all have Body by Fisher, is it a Custom or a Limited?

[2002 Caddy]

Originally Posted by EPA2

Cross-fire also faired pretty well among the different automotive magazines back in the day, the reviews were pretty favorable. The system was reliable and it provided good performance for its day, and it put money into GM's pocket. In closing the Cross-Fire system was a success.

To be accurate, In the world of F'Bodies... CrossFire was less then a 1 hit wonder... By march of 1983, less then 18 months after its launch, it was over shadowed by the L69 motor..

Fewer then 40,000 Camaros ever got this engine... even fewer Firebirds.. Only about 11% of the cars made in 1982 and 83 came this way... and as I said by March of 1983 the LU5 engine was dead... 0 were installed in 1984 F Bodies... In 1982 & 83 the Carburated V8 out sold by around 5:1

The L69 was sadly proof positive of just how bad a EFI system Crossfire was... In this case GM engineers simply ripped off the EFI system, replace that with a CCC Q-Jet and an old school dual plane intake, update the exhaust system and tada you were making with a Carburetor originally designed in the 60's... 15 more HP then a brand new EFI system.

This Carb system even beat out the EFI base motor that you point to as the Crossfire sucessor in 1988 (170 HP)

The TPI's on the other hand, were great motors, easily tunable, and loved by all...

[prowlerjc]

Originally Posted by EPA2

As I mentioned before, the same spec TBI from the dual TBI 5.0 liter Cross-Fire system was used starting in 1982 on the 2.5 liter Iron Duke and provided reliable service for millions of the different GM customers.

The only way to kill an Iron Duke was to put it in a Fiero.

[EPA2]

Originally Posted by 2002 Caddy

To be accurate, In the world of F'Bodies... CrossFire was less then a 1 hit wonder... By march of 1983, less then 18 months after its launch, it was over shadowed by the L69 motor..

Fewer then 40,000 Camaros ever got this engine... even fewer Firebirds.. Only about 11% of the cars made in 1982 and 83 came this way... and as I said by March of 1983 the LU5 engine was dead... 0 were installed in 1984 F Bodies... In 1982 & 83 the Carburated V8 out sold by around 5:1

The L69 was sadly proof positive of just how bad a EFI system Crossfire was... In this case GM engineers simply ripped off the EFI system, replace that with a CCC Q-Jet and an old school dual plane intake, update the exhaust system and tada you were making with a Carburetor originally designed in the 60's... 15 more HP then a brand new EFI system.

This Carb system even beat out the EFI base motor that you point to as the Crossfire sucessor in 1988 (170 HP)

The TPI's on the other hand, were great motors, easily tunable, and loved by all...

The 5.0 liter Cross-Fire was produced through the end of the 1983 model year for the Z28 and Trans Am. The L69 was not released until March of 1983 as you mentioned however it was not promoted at all, in fact some salesmen did not even know the option existed in late 1983. Only 662 1983 Trans Ams came equipped with the L69 5.0 H.O. V8. which was around 2% of total Trans Am production (32,020) for 1983 model year.

The L69 was a LU5 Cross-Fire motor with a freeflow intake manifold and a high performance Rochester Quadrajet. Both the L69 and LU5 shared the same camshaft, fortified engine block (which was different from the LG4 block), and high performance heads (58cc chambers - 9.5:1 compression ratio). Of course the L69 was a much better performing motor. When looking at a LU5/Corvette's L83 Cross-Fire intake while it is off the engine and comparing it to the L69's free-flow intake, it's no surprise. The Cross-Fire intake is the most restrictive intake you could ever expect to see on a V8 engine (barring of course a restrictive 2bbl intake). As I mentioned before the Cross-Fire intake only flowed a measly 475 CFM. This was the Cross-Fire engine's choking point. The L69 flowed at least 50% better, of course it's going to perform better. The 4bbl quadrajet on the L69 flowed a solid 795 CFM (the LG4 4bbl quadrajet carb was 750 CFM). The restrictive intake crippled the potential of the Cross-Fire system. And add on to that there was no manual transmission option since Chevy engineers could not get a 5.0 liter Cross-Fire EPA certified.

Cross-Fire was an expensive option on the Z28 and Trans Am back in 1982 and 1983 the difference of 20 horsepower (25 horsepower for 1983) vs. the LG4 was not enough for many people to warrant paying a lot more for their Trans Am and Z28. And traditionally base motors in the Camaro Z28 and Trans Am sold in much higher numbers than the top-of-the-line performance motors. For instance the base Pontiac 400 (L78) outsold by almost 8 times the much better performing (now sought by collectors) W72 Pontiac 400 (factory rated at 220 horsepower but NHRA rated it stock at 260 horsepower) 1978 Trans Am. Most people in 1978 did not see the need to upgrade to the more high-performance W72. It's the nature of the beast on these f-bodies and most years from the 1st to 3rd generation the best performing motor each year was outsold by large margins by the base motor of that same year.

The LO3 1988 - 1992 TBI 5.0 liter V8 was intended to be a LG4 replacement and made five horsepower more than the 1987 LG4. It was an improvement in performance. It was not tuned to be on par with the L69 which had a hotter cam, heads, and other performance tweeks the LO3 did not have.

The 5.7 and 5.0 TPI motors were by far the best motors in GM's aresenol (exception of course is the Buick SFI turbo 3.8 V6) during the 1980s and early 1990s. However there would have been no TPI motors if there were no LU5 and LG4 engines available early in 3rd gen f-body production, these motors kept performance alive, and both deserve a little credit for that.

There was one downside to the 5.7 TPI, it never came with a manual transmission option. A 6-speed manual equipped 5.7 TPI f-body would have been real nice.

As I mentioned before Cross-Fire was a transitional motor, it provided enough performance and it was reliable. If Chevy would have gotten a manual transmssion certified for the 5.0 LU5 and the darn intake was not so restrictive it may have stayed around a few extra years. Never-the-less that's history...