Exhaust

[mickeystoys69RSSS]

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?

[bertfam]

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]

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...

[69Z28]

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"?

[1968 Z28]

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.

[69Z28]

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?

[ZLP955]

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" ??

[llskis]

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

[william]

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]

I sent you an e-mail William...Joe