Chevy 454 Smog Emission Manifold

[heyaim]

We have a 1986 Allegro motorhome. On one of our trips our smog emission manifold broke off on the left side. The right side was showing signs of breaking also. She's been at the mechanic for the last week for repair. Has anyone else had this happen? From what DH has said, this smog emission isn't on all 454s...mainly motorhomes and corvettes.

Hopefully we should be able to pick up the mh today or tomorrow! Crossing my fingers so hopefully we can plan to go somewhere next weekend...my weekend off work!

[DriVer]

Quote:

Originally Posted by heyaim Hopefully we should be able to pick up the mh today or tomorrow! Crossing my fingers so hopefully we can plan to go somewhere next weekend...my weekend off work!

heyaim, That's too bad when stuff like that happens and tries to ruin your weekend. Good luck on the repair and enjoy your weekend. I'm sure that you deserve it!

[GOLDWINGER2]

Quote:

Originally Posted by heyaim We have a 1986 Allegro motorhome. On one of our trips our smog emission manifold broke off on the left side. The right side was showing signs of breaking also. She's been at the mechanic for the last week for repair. Has anyone else had this happen? From what DH has said, this smog emission isn't on all 454s...mainly motorhomes and corvettes. Hopefully we should be able to pick up the mh today or tomorrow! Crossing my fingers so hopefully we can plan to go somewhere next weekend...my weekend off work!

Are you talking about the exhaust manifolds? Since you are in a
"No Smog Test" state, headers would be a good repair. In 1986 Corvettes did not have 454 engines.
J

[bigskymt]

The P-30s were famous for cracked exhaust manifolds, if that's what you're referring to. Doug Thorley makes headers either with or without the AIR input ports attached. If you live in a 'smog test' state you will have to fashion a mount for the vacuum controled exhaust valve installed at the bottom of the header on the right bank. You will probably notice a slight improvement in performance with headers.
In the 80's emission controls varied widely by individual vehicle: Gross weight, reg. or unleaded gas, etc. CA had lower emmision levels then the Feds for several years so a vehicle manufactured for sale in CA would have more emission controls then the same vehicle sold in another state.