Dumb 454 manifold question
Thread Starter
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
Dumb 454 manifold question
Are these unused A I R tubes necessary? Can I remove them?
My car is all original and never had the A I R pump.
The passages on the outside of the manifold are plugged with allen heads that will never come out after 50 years.
I'm wondering about these A I R pipes that lead into the exhaust to help with the flow from the pump.
They spin freely and it seems to me they will eventually rust and disintegrate into the exhaust.
My car is all original and never had the A I R pump.
The passages on the outside of the manifold are plugged with allen heads that will never come out after 50 years.
I'm wondering about these A I R pipes that lead into the exhaust to help with the flow from the pump.
They spin freely and it seems to me they will eventually rust and disintegrate into the exhaust.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,151
Likes: 4,264
From: US-PNW
Well, they haven't rusted and disintegrated in the last 50 years...
What year is the car? A.I.R. (smog) pumps date back to the mid-'60s on certain engines and/or delivery locations. That your manifold has the holes/tubes for the pump seems to indicate it originally had the system. (Do both manifolds have the holes?) Those cars that did not have the A.I.R. system installed did not have manifolds with the holes/tubes.
What year is the car? A.I.R. (smog) pumps date back to the mid-'60s on certain engines and/or delivery locations. That your manifold has the holes/tubes for the pump seems to indicate it originally had the system. (Do both manifolds have the holes?) Those cars that did not have the A.I.R. system installed did not have manifolds with the holes/tubes.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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YOu may want to sell those and by some that are already cut up...Someone may give you a stupid amount of money for original manifolds with those lines
Melting Slicks
Joined: Nov 2006
Posts: 3,416
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From: Apple Valley, MN
Don’t disagree with @Rescue Rogers but be very careful about buying replacements as these manifolds can be cracked, rusted thin, welded on, etc, etc.
Pro
Joined: Jul 2004
Posts: 713
Likes: 61
From: Waterford CT
Take the tubes out and keep your uncracked manifolds. If you don't have the AIR manifold you can use plugs. The tubes are a loose part inserted from the outside before the smog pipe manifold is installed. I removed them on my LT-1 because of the flow restriction even though I have the full AIR system present. The tubes were there to dump the incoming fresh air as close as possible to the hot exhaust port to maximize the effectiveness of the system. Since most of us don't really care if we pollute a tiny bit more with our old cars, the tubes don't need to be there. I actually only found 7 tubes present when I opened mine up. Someone in the past had already taken one out.
Burning Brakes
Joined: Dec 2006
Posts: 979
Likes: 254
From: Bethlehem, PA
You don't say what year engine you have, but if your exhaust manifolds have plugs it originally had smog tubes. Removing the plugs can be very difficult, but to remove those tubes intact you need to remove the plugs. If you think they are a problem and can't/dont want to remove the plugs, cut them off best you can.
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Thread Starter
Burning Brakes
Joined: Oct 2011
Posts: 956
Likes: 86
From: McDonough Georgia
The car is a 74, 454 LS4.
I believe they are made of stainless. They just sit in there with a lip holding them in. So they are loose and floppy and spin.
I lifted up on them as high as possible and cut them off with a dremel. Then I turned them sideways and used a punch to tap them flat. Simple to pry them out.
This car may have come with an A I R pump originally. From what I can decipher, it was removed decades ago. I don't believe the manifold was ever removed. That is why those little pipes were still in there. Those allen heads are never coming out with a wrench. Only a drill and re-tapping will put them back to original. I can live with them the way they are.
I believe they are made of stainless. They just sit in there with a lip holding them in. So they are loose and floppy and spin.
I lifted up on them as high as possible and cut them off with a dremel. Then I turned them sideways and used a punch to tap them flat. Simple to pry them out.
This car may have come with an A I R pump originally. From what I can decipher, it was removed decades ago. I don't believe the manifold was ever removed. That is why those little pipes were still in there. Those allen heads are never coming out with a wrench. Only a drill and re-tapping will put them back to original. I can live with them the way they are.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,151
Likes: 4,264
From: US-PNW
I realize this is just academic stuff that a lot of folks don't care about, but here goes anyway. The following is from Jim Shea back in 2006:
Here is what I have for A.I.R. useage in the Vettes. I may have obtained this information from Saginaw Steering Gear who manufactured the original A.I.R. pumps.
1966 California delivered Vettes used the A.I.R. (RPO K-19) system except for L-72.
1967 All California delivered Vettes used the A.I.R. (RPO K-19) system.
1968 & 1969 All Corvettes used the A.I.R. system regardless of engine or transmission.
1970 Chevrolet went to the CCS (Controlled Combustion System) for emissions control on most Vettes except the LT-1s which used A.I.R.
1971 Corvettes continued with CCS (except LT-1s and LS-6s which used A.I.R.
1972 The A.I.R. system returned for most Vettes except L48s with the "CKW" and "CKX" codes.
1973-1975 All Vettes used A.I.R. except for the 1974 L48 with automatic and Federal emissions which used CSS.
1976 All Vettes returned to CCS except California certified cars which used A.I.R.
1977 All Vettes used CCS except California and "High Altitude" delivered cars which used A.I.R.
(Not sure on the 1976 and 1977 Vettes with L82s, they might have used A.I.R.)
1978 & 1979 All Corvettes used CCS except California cars, "high altitude" and all L82s which used A.I.R. L82s were not available in California or "high altitude" areas during these years.
1980-1987 All Vettes used A.I.R.
Hope this helps,
Jim
1966 California delivered Vettes used the A.I.R. (RPO K-19) system except for L-72.
1967 All California delivered Vettes used the A.I.R. (RPO K-19) system.
1968 & 1969 All Corvettes used the A.I.R. system regardless of engine or transmission.
1970 Chevrolet went to the CCS (Controlled Combustion System) for emissions control on most Vettes except the LT-1s which used A.I.R.
1971 Corvettes continued with CCS (except LT-1s and LS-6s which used A.I.R.
1972 The A.I.R. system returned for most Vettes except L48s with the "CKW" and "CKX" codes.
1973-1975 All Vettes used A.I.R. except for the 1974 L48 with automatic and Federal emissions which used CSS.
1976 All Vettes returned to CCS except California certified cars which used A.I.R.
1977 All Vettes used CCS except California and "High Altitude" delivered cars which used A.I.R.
(Not sure on the 1976 and 1977 Vettes with L82s, they might have used A.I.R.)
1978 & 1979 All Corvettes used CCS except California cars, "high altitude" and all L82s which used A.I.R. L82s were not available in California or "high altitude" areas during these years.
1980-1987 All Vettes used A.I.R.
Hope this helps,
Jim