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Second Charcoal Canister Needed?

T
tomkatz3@comcast.net
Wed, Jul 28, 2021 12:45 AM

Good evening all,

I have a 1977 23' Birchaven with 2 Charcoal Canisters. Is it worthwhile to keep 2 canisters or only necessary to have one?

Take care,
Tom K.

Tom & Oki Katzenberger,
Kingsville, Maryland,
1977 23' Birchaven, 455 C.I.D.

Good evening all, I have a 1977 23' Birchaven with 2 Charcoal Canisters. Is it worthwhile to keep 2 canisters or only necessary to have one? Take care, Tom K. -- Tom & Oki Katzenberger, Kingsville, Maryland, 1977 23' Birchaven, 455 C.I.D.
JH
James Hupy
Wed, Jul 28, 2021 12:51 AM

One of those canisters traps gasoline tank expansion fumes, and routes it
to the inlet tract of the Carburetor. The other one takes the Carburetor
float bowl fuel expansion fumes and does the same thing. They both work to
reduce UHC in the atmosphere. I f they are serviceable,  I would leave them
in place and make sure they work. Your experiences may vary.
Jim Hupy
Salem, Oregon

On Tue, Jul 27, 2021, 5:45 PM tomkatz3@comcast.net wrote:

Good evening all,

I have a 1977 23' Birchaven with 2 Charcoal Canisters. Is it worthwhile to
keep 2 canisters or only necessary to have one?

Take care,
Tom K.

Tom & Oki Katzenberger,
Kingsville, Maryland,
1977 23' Birchaven, 455 C.I.D.


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One of those canisters traps gasoline tank expansion fumes, and routes it to the inlet tract of the Carburetor. The other one takes the Carburetor float bowl fuel expansion fumes and does the same thing. They both work to reduce UHC in the atmosphere. I f they are serviceable, I would leave them in place and make sure they work. Your experiences may vary. Jim Hupy Salem, Oregon On Tue, Jul 27, 2021, 5:45 PM <tomkatz3@comcast.net> wrote: > Good evening all, > > I have a 1977 23' Birchaven with 2 Charcoal Canisters. Is it worthwhile to > keep 2 canisters or only necessary to have one? > > Take care, > Tom K. > -- > Tom & Oki Katzenberger, > Kingsville, Maryland, > 1977 23' Birchaven, 455 C.I.D. > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
JR
John R. Lebetski
Wed, Jul 28, 2021 1:17 AM

The carbon canisters are engineering simplicity at it’s finest. Burning fuel vapors instead of venting to our atmosphere.  I see no down sides to
having them, only benefit.

John Lebetski
Woodstock, IL
77 Eleganza II

The carbon canisters are engineering simplicity at it’s finest. Burning fuel vapors instead of venting to our atmosphere. I see no down sides to having them, only benefit. -- John Lebetski Woodstock, IL 77 Eleganza II
SS
Steve Southworth
Wed, Jul 28, 2021 1:31 AM

James Hupy wrote on Tue, 27 July 2021 19:51

One of those canisters traps gasoline tank expansion fumes, and routes it
to the inlet tract of the Carburetor. The other one takes the Carburetor
float bowl fuel expansion fumes and does the same thing. They both work to
reduce UHC in the atmosphere. I f they are serviceable,  I would leave them
in place and make sure they work. Your experiences may vary.
Jim Hupy
Salem, Oregon

As a side note:  Our ‘74 has two emissions canisters connected in series as the tank vent.  This was part of the California emissions which also
included gas tank heat shields on the exhaust pipe.  (Coach was sold in Missouri so no idea why it has a CA emissions package.)

Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

James Hupy wrote on Tue, 27 July 2021 19:51 > One of those canisters traps gasoline tank expansion fumes, and routes it > to the inlet tract of the Carburetor. The other one takes the Carburetor > float bowl fuel expansion fumes and does the same thing. They both work to > reduce UHC in the atmosphere. I f they are serviceable, I would leave them > in place and make sure they work. Your experiences may vary. > Jim Hupy > Salem, Oregon As a side note: Our ‘74 has two emissions canisters connected in series as the tank vent. This was part of the California emissions which also included gas tank heat shields on the exhaust pipe. (Coach was sold in Missouri so no idea why it has a CA emissions package.) -- Steve Southworth 1974 Glacier TZE064V100150 (for workin on) 1975 Transmode TZE365V100394 (parts & spares) Palmyra WI
JH
James Hupy
Wed, Jul 28, 2021 1:38 AM

That's a strange one. 2 canisters were introduced with the 403 in
California equipped coaches in mid year 1977. 1978 saw all coaches
(California and 48 states equipped) with 2 canisters.  But they are 40+
years old, and "little Tommy tinkerer" has had his way with them. All kinds
of changes have magically appeared in these coaches.
Jim Hupy
Salem, Oregon

On Tue, Jul 27, 2021, 6:32 PM Steve Southworth stevesouthw@gmail.com
wrote:

James Hupy wrote on Tue, 27 July 2021 19:51

One of those canisters traps gasoline tank expansion fumes, and routes it
to the inlet tract of the Carburetor. The other one takes the Carburetor
float bowl fuel expansion fumes and does the same thing. They both work

to

reduce UHC in the atmosphere. I f they are serviceable,  I would leave

them

in place and make sure they work. Your experiences may vary.
Jim Hupy
Salem, Oregon

As a side note:  Our ‘74 has two emissions canisters connected in series
as the tank vent.  This was part of the California emissions which also
included gas tank heat shields on the exhaust pipe.  (Coach was sold in
Missouri so no idea why it has a CA emissions package.)

Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI


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Unsubscribe or Change List Options:

That's a strange one. 2 canisters were introduced with the 403 in California equipped coaches in mid year 1977. 1978 saw all coaches (California and 48 states equipped) with 2 canisters. But they are 40+ years old, and "little Tommy tinkerer" has had his way with them. All kinds of changes have magically appeared in these coaches. Jim Hupy Salem, Oregon On Tue, Jul 27, 2021, 6:32 PM Steve Southworth <stevesouthw@gmail.com> wrote: > James Hupy wrote on Tue, 27 July 2021 19:51 > > One of those canisters traps gasoline tank expansion fumes, and routes it > > to the inlet tract of the Carburetor. The other one takes the Carburetor > > float bowl fuel expansion fumes and does the same thing. They both work > to > > reduce UHC in the atmosphere. I f they are serviceable, I would leave > them > > in place and make sure they work. Your experiences may vary. > > Jim Hupy > > Salem, Oregon > > As a side note: Our ‘74 has two emissions canisters connected in series > as the tank vent. This was part of the California emissions which also > included gas tank heat shields on the exhaust pipe. (Coach was sold in > Missouri so no idea why it has a CA emissions package.) > -- > Steve Southworth > 1974 Glacier TZE064V100150 (for workin on) > 1975 Transmode TZE365V100394 (parts & spares) > Palmyra WI > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
MC
Matt Colie
Wed, Jul 28, 2021 3:11 AM

No Mystery Here.

At the time of production, there was an EPA rule that required the vehicle to absorb HC vapors based on the fuel tank volume.  Many coaches were fit
with the series canisters.  Mine was and is was sold in Michigan and later move to southern California.

To really answer your mystery, if you leave then alone you will never know that they are there.  If like me, you want to decrease the spinach factor,
look at them carefully, and you can figure out how they are stacked and take out the one that is the add-on.  As long as the vapor separator in the
left hind wheel well works, you will never know about it.

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

No Mystery Here. At the time of production, there was an EPA rule that required the vehicle to absorb HC vapors based on the fuel tank volume. Many coaches were fit with the series canisters. Mine was and is was sold in Michigan and later move to southern California. To really answer your mystery, if you leave then alone you will never know that they are there. If like me, you want to decrease the spinach factor, look at them carefully, and you can figure out how they are stacked and take out the one that is the add-on. As long as the vapor separator in the left hind wheel well works, you will never know about it. Matt -- Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms SE Michigan - Near DTW - Twixt A2 and Detroit
T
tomkatz3@comcast.net
Wed, Jul 28, 2021 1:18 PM

Thank you all. Mine are in a series. I think I will leave them as they are. I see no harm with the exception of more to go wrong. The best part is no
part I guess.

Take care and have a wonderful day,
Tom K

Tom & Oki Katzenberger,
Kingsville, Maryland,
1977 23' Birchaven, 455 C.I.D.

Thank you all. Mine are in a series. I think I will leave them as they are. I see no harm with the exception of more to go wrong. The best part is no part I guess. Take care and have a wonderful day, Tom K -- Tom & Oki Katzenberger, Kingsville, Maryland, 1977 23' Birchaven, 455 C.I.D.
KB
Ken Burton
Thu, Jul 29, 2021 2:57 AM

My 76 California coach came with and still has two canisters in series and also the exhaust heat shields.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

My 76 California coach came with and still has two canisters in series and also the exhaust heat shields. -- Ken Burton - N9KB 76 Palm Beach Hebron, Indiana
T
tomkatz3@comcast.net
Thu, Jul 29, 2021 4:05 PM

Thank you Ken, I have exhaust shield as well. I thought someone just added them, perhaps they are factory.

Tom & Oki Katzenberger,
Kingsville, Maryland,
1977 23' Birchaven, 455 C.I.D.

Thank you Ken, I have exhaust shield as well. I thought someone just added them, perhaps they are factory. -- Tom & Oki Katzenberger, Kingsville, Maryland, 1977 23' Birchaven, 455 C.I.D.
KB
Ken Burton
Fri, Jul 30, 2021 4:25 AM

The part is listed in the parts book as California only.  Mine rusted the bracket and partially fell off.  I rebuuilt it and reinstalled it again.
Jim K and another GMCer decided to start making them since it is a simple bent up piece of sheet metal (and mounting brackets) and easy to install.  I
thought it was a good idea to try to keep exhaust pipe heat down and from entering the gasoline in the tanks.

JimK. Still has them and it is an easy improvement.  I mention all of this because there are some unknoow number of these shields out there installed
by GMCers on non-California sold coaches.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

The part is listed in the parts book as California only. Mine rusted the bracket and partially fell off. I rebuuilt it and reinstalled it again. Jim K and another GMCer decided to start making them since it is a simple bent up piece of sheet metal (and mounting brackets) and easy to install. I thought it was a good idea to try to keep exhaust pipe heat down and from entering the gasoline in the tanks. JimK. Still has them and it is an easy improvement. I mention all of this because there are some unknoow number of these shields out there installed by GMCers on non-California sold coaches. -- Ken Burton - N9KB 76 Palm Beach Hebron, Indiana