72 exhaust manifolds ls5

[ERIC FAIRCLOUGH]

Hello, I just pulled my exhaust manifolds and was wondering what the little metal rods are that bolt into the exhaust manifold? There are four on each all of them almost touching each valve. Thanks Eric

[Joe L.]

Re: 72 exhaust manifolds ls5

Eric----

They're not rods; they're tubes. These are the tubes for the air injection system. Yours may be fully "encrusted" with exhaust deposits and appear like rods now, though.

[Eric Fairclough]

Re: 72 exhaust manifolds ls5

Joe, How does the air injection system work? Eric

[Joe L.]

Re: 72 exhaust manifolds ls5

Eric-----

It is an exhaust emissions control system. It simply provides fresh air at the exhaust ports in order to oxidize (burn off) excess hydrocarbons in the exhaust gasses. The air is forced into the manifolds as a result of the action of the AIR pump. During certain engine operating regimes when the air would cause backfiring, the diverter valve "dumps" the pump's output to atmosphere.

[Eric Fairclough]

Re: 72 exhaust manifolds ls5

Thanks Joe, I was wondering how it worked. Mine must have had a air pump at one point and someone took it off and closed the air ports in the manifold. Thanks Eric

[Joe L.]

Re: 72 exhaust manifolds ls5

Eric-----

It definitely did originally come equipped with AIR. All 1972 Corvettes with LS-5 were originally equipped with AIR.

[Eric Fairclough]

Re: 72 exhaust manifolds ls5

Joe , I though that air injection was an option that mine did not come with. Thanks for the help. Eric

[Joe L.]

Re: 72 exhaust manifolds ls5

Eric-----

Air Injection was decidely NOT an option. If it had been, I doubt that a single one would have been sold. It was installed on cars at the "option" of the federal government.