catalytic converters

[Guest tim sheard]

If I put a pair of catalytic converters on my '69 Avanti (327 cubic inch with 3-speed trans), will it damage the engine? I don't mind losing a few horsepower, it's plenty fast as is. thank you. tim sheard, brooklyn.

[Gunslinger]

It shouldn't hurt a thing beyond introducing some additional back pressure into the exhaust. You can buy low-restriction converters through Summit Racing and Jeg's that will minimize any horsepower penalty.

That brings up the obvious question...what would want to install cats on a car that has no need or requirement for them?

[IndyJimW]

I wouldn't recommend it. Not that it would cause the engine problems but because older carburated engines use an air pump to supply additional air to the exhaust to get the converter to work. Without this air the converters would probabily plug up pretty quick.

[Guest tim sheard]

I wouldn't recommend it. Not that it would cause the engine problems but because older carburated engines use an air pump to supply additional air to the exhaust to get the converter to work. Without this air the converters would probabily plug up pretty quick.

<{POST_SNAPBACK}>

Dear Indy Jim,

Thanks for the info about catalytic converters plugging up quickly. I live in Brooklyn, where the air is not the best, and I'd like to run as clean a car as I can.

tim sheard, brooklyn