Author Topic: Exhaust  (Read 3954 times)

DyRally-Z1986

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Exhaust
« on: August 15, 2013, 05:58:38 PM »
Can you guys tell me if an O1C build date Z/28 would of came factory with Chambered Exhaust? Thanks!

Ed_B

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Re: Exhaust
« Reply #1 on: August 15, 2013, 06:36:09 PM »
RPO NC8 was standard on the 1969 Z28 until November 25th, 1968. After that it became optional, and then discontinued on May 19th, 1969.

Ed

DyRally-Z1986

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Re: Exhaust
« Reply #2 on: August 15, 2013, 07:10:29 PM »
So it being a January 69 car means it's optional?

Ed_B

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Re: Exhaust
« Reply #3 on: August 15, 2013, 07:17:39 PM »
Correct.

Ed

DyRally-Z1986

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Re: Exhaust
« Reply #4 on: August 15, 2013, 07:50:55 PM »
Thanks again!

69Z28-RS

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Re: Exhaust (Another Exhaust question)
« Reply #5 on: August 15, 2013, 08:53:41 PM »
For late '69 Camaros, after discontinuation of the NC8 (chambered), and after the introduction of the resonators to the standard transverse muffler system, What was the diameter of the exhaust (head) pipe off of the manifolds??    People who sale these, list both 2" and 2-1/4" diameter.  Which is correct, and acceptable in the judged original classes?
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
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Ed_B

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Re: Exhaust
« Reply #6 on: August 15, 2013, 09:19:59 PM »
I "believe" the head pipes themselves are 2" where they attach to the exhaust manifolds, and then expand out to 2.25", but I'll ask John and/or Jerry to verify this. I say this because the same exhaust manifolds were used on the L48 (350/300), and this had a 2" based dual exhaust system. I don't think any 60's small block exhaust manifolds had anything greater than a 2" outlet other than the higher performance C2 Corvettes, which had 2.5".

Ed

mickeystoys69RSSS

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Re: Exhaust
« Reply #7 on: August 15, 2013, 11:53:56 PM »
On duel exhaust small blocks including the SS 350 had the 2". The 302 Z/28 and big blocks had the 2-1/4"

z28z11

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Re: Exhaust
« Reply #8 on: August 16, 2013, 02:10:53 AM »
RPO NC8 was standard on the 1969 Z28 until November 25th, 1968. After that it became optional, and then discontinued on May 19th, 1969.

Ed


Hey Ed,

I've got a documented X33 Z here locally, a May car, with an original chambered exhaust system on it, or what's left of it. Would the option have shown on the dealer invoice (the documentation) for this car ? I've got the MSO copy as well - I have always wondered if it was one of the last to have gotten the chambered exhaust before option delete -

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

llskis

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Re: Exhaust
« Reply #9 on: August 16, 2013, 12:19:41 PM »
Can you guys tell me if an O1C build date Z/28 would of came factory with Chambered Exhaust? Thanks!

FWI: The last entry on the NC8 option in tha AIM is 6/13/69 indicating the RPO is cancelled. Larry
1969 Z28 Non-Radio and Jeriry MacNeish Certified

paceme

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Re: Exhaust
« Reply #10 on: August 16, 2013, 01:28:28 PM »
RPO NC8 was standard on the 1969 Z28 until November 25th, 1968. After that it became optional, and then discontinued on May 19th, 1969.

Ed


Hey Ed,

I've got a documented X33 Z here locally, a May car, with an original chambered exhaust system on it, or what's left of it. Would the option have shown on the dealer invoice (the documentation) for this car ? I've got the MSO copy as well - I have always wondered if it was one of the last to have gotten the chambered exhaust before option delete -

Regards,
Steve

Once the NC8 was no longer standard equipment, it became and option and would be listed on the invoice/window sticker like any other ordered option.
Steve Shauger
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JohnZ

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Re: Exhaust
« Reply #11 on: August 16, 2013, 02:22:15 PM »
Can you guys tell me if an O1C build date Z/28 would of came factory with Chambered Exhaust? Thanks!

FWI: The last entry on the NC8 option in tha AIM is 6/13/69 indicating the RPO is cancelled. Larry

Remember that the dates in the revision block in the A.I.M. are only the date the sheet was revised in the Drafting Room, not the date the revision occurred in production; NC8 was cancelled on May 19th.
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Ed_B

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Re: Exhaust
« Reply #12 on: August 16, 2013, 04:53:38 PM »
In 1969 (for the N10 exhaust), both the Z28 and L48 had 2.25" head pipes EXCEPT where they attached to the exhaust manifolds. That "connection point" was 2" but I'm not sure how far that 2" pipe extended down until it turned into 2.25". The "over the axle" pipes were also 2.25", but the tail pipes were 2".

For NC8, the Z28 headpipes were 2.25" in diameter EXCEPT where they attached to the exhaust manifolds. Again, that "Connection point" was 2" like the N10, and again, I don't know how far down it extended until it turned into 2.25". The short "over the axle" pipes were 2" after that first chambered section and then the tailpipes were also 2".

Steve, take a look at page 109 in Jerry's "The Definitive 1969 Camaro Z28-SS396 Fact Book" and you'll see a shipper of a April, 1969 Z28 with the NC8 option.

Ed

llskis

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Re: Exhaust
« Reply #13 on: August 16, 2013, 05:05:27 PM »
Can you guys tell me if an O1C build date Z/28 would of came factory with Chambered Exhaust? Thanks!

FWI: The last entry on the NC8 option in tha AIM is 6/13/69 indicating the RPO is cancelled. Larry

Remember that the dates in the revision block in the A.I.M. are only the date the sheet was revised in the Drafting Room, not the date the revision occurred in production; NC8 was cancelled on May 19th.

What GM documantation backs up your(or anybody elses) exact date of May 19th?? Just curious. Larry
1969 Z28 Non-Radio and Jeriry MacNeish Certified

Ed_B

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Re: Exhaust
« Reply #14 on: August 16, 2013, 05:47:41 PM »
Quote
What GM documantation backs up your(or anybody elses) exact date of May 19th?? Just curious. Larry

Larry, here's the the Zone Letter showing the discontinuation of the NC8 exhaust because of the incorporation of the chrome exhaust tips.

Ed


mickeystoys69RSSS

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Re: Exhaust
« Reply #15 on: August 17, 2013, 12:12:55 AM »

For NC8, the Z28 headpipes were 2.25" in diameter EXCEPT where they attached to the exhaust manifolds. Again, that "Connection point" was 2" like the N10, and again, I don't know how far down it extended until it turned into 2.25". The short "over the axle" pipes were 2" after that first chambered section and then the tailpipes were also 2".



Anyone know if this was the same as the big block cars? I have a chambered exhaust 11C build car with 2" at the tips or should it be 2-1/4?

Ed_B

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Re: Exhaust
« Reply #16 on: August 17, 2013, 12:59:25 AM »
Quote
Anyone know if this was the same as the big block cars? I have a chambered exhaust 11C build car with 2" at the tips or should it be 2-1/4?

If you look in the AIM, you'll see the only parts that are different on the big blocks are the head pipes. The rest is all the same.

Ed

69Z28-RS

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Re: Exhaust
« Reply #17 on: August 17, 2013, 01:52:12 AM »
Ed, others,

Thanks for the information on the Z28 exhaust (head) pipe diameter... and that 9May letter would seem to put the question on NC8 to rest (on Camaros), as it stated the *effective date* for discontinuation of the option is May19.   To me, that says unless your car was produced on 18May or earlier, it has zero chance of having come from the factory with NC8...
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
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69Z28

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Re: Exhaust
« Reply #18 on: August 17, 2013, 02:33:54 AM »
I asked this previously and was told 2" for a 69 z28 at the headpipe to manifold connection. Still need to order
packing donuts and the extensions and do not want to order the wrong parts, so what is correct 2" or 2 1/4"?
GaryC

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1968 Z28

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Re: Exhaust
« Reply #19 on: August 17, 2013, 03:42:49 AM »
In 1969 (for the N10 exhaust), both the Z28 and L48 had 2.25" head pipes EXCEPT where they attached to the exhaust manifolds. That "connection point" was 2" but I'm not sure how far that 2" pipe extended down until it turned into 2.25". The "over the axle" pipes were also 2.25", but the tail pipes were 2".

For NC8, the Z28 headpipes were 2.25" in diameter EXCEPT where they attached to the exhaust manifolds. Again, that "Connection point" was 2" like the N10, and again, I don't know how far down it extended until it turned into 2.25". The short "over the axle" pipes were 2" after that first chambered section and then the tailpipes were also 2".

Steve, take a look at page 109 in Jerry's "The Definitive 1969 Camaro Z28-SS396 Fact Book" and you'll see a shipper of a April, 1969 Z28 with the NC8 option.

Ed

I think Ed covers this....2" at the end connection point  (the connection to the exhaust pipe on one side and the heat valve on the other side) that increases to 2 1/4" from about one or two inches below the connection all the way to the muffler.
Jerry G.

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69Z28

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Re: Exhaust
« Reply #20 on: August 17, 2013, 05:06:24 AM »
Ok. 2" at the heat valve both sides, flat gasket side and packing donut side, and 2 1/4" at a few inches bellow that on the head pipe correct? At no point is the connection to the manifold and heat valve greater than 2"? Where the extention fits into the headpipe to hold the packing donut to the heat valve, this will be 2" correct?
GaryC

'UNRESTORED' 1969 Cortez Silver X33D80 Z28

ZLP955

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Re: Exhaust
« Reply #21 on: August 17, 2013, 08:38:15 AM »
Interesting that the Zone Letter refers to discontinuation of NC8 dual chambered exhaust for "Camaro SS". If that included Z28, perhaps it was a typo and meant to be "Camaros" ??
Tim - 04A VN '69 z/28 69-69 715 ex-E/MP

llskis

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Re: Exhaust
« Reply #22 on: August 17, 2013, 12:52:54 PM »
Interesting that the Zone Letter refers to discontinuation of NC8 dual chambered exhaust for "Camaro SS". If that included Z28, perhaps it was a typo and meant to be "Camaros" ??

Another question comes about is what happened to all the Chamber Pipes and Hardware that where left in the production line bins at the time of                                         May 19? I think we can all assume that the supply of the Chamber Pipes and Hardware didn't run out on May 19th. Would not GM want to use up
the supplies then change it plans like they do with all there other change over parts?? Larry
1969 Z28 Non-Radio and Jeriry MacNeish Certified

william

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Re: Exhaust
« Reply #23 on: August 17, 2013, 02:37:11 PM »
Removing obsolete inventory due to a current model year engineering change is SOP in any manufacturing plant. Engineering paperwork is routed through Production Control as there may be inventory at the source, in transit and on the line. The disposition of that material has to be determined: use up, scrap, ship to GMPD. I bought a complete NC8 set up from a Chevy dealer in 1975 so they must have diverted it for service usage.

May 19, 1969 was a Monday so I will venture to say all NC8 componentry was removed from Norwood & Van Nuys and sent to GMPD over the weekend.

Another wrinkle to the NC8 story has recently come to light. I correspond with a guy that has devoted much of the past 30 years or so to the pursuit of original 1969 Camaros and OE parts. He has examined several 2nd design original exhaust cars and early LH tailpipes were not 2-piece construction. It appears Chevy had standard N10 LH tailpipes polished and flash-chromed in order to meet the May 19 date. Later cars and service parts were the 2-piece construction. 

x66 714

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Re: Exhaust
« Reply #24 on: August 18, 2013, 01:58:48 PM »
I sent you an e-mail William...Joe
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