Putting catalytic converter on older car?

[roflwaffle]

Originally Posted by Trackerrrr

I suspected the carb would be the sticking point for a cat. Too many variables and inability to control the air/fuel ratio closely enough.

You can control it fairly well post combustion (smog pump) by either developing your own control unit for a smog pump/1 wire oxygen sensor so the cat could work or finding a system (I think it's called a FFS in emissions lingo) from an ~80s/90s engine of similar displacement and retrofitting that. Given all the work involved I think a conversion to TBI w/ megasquirt would be easier, cheaper, and also improve mileage.

[PhilA]

It's possible but a headache, carbs and cats don't mix well.

My Briggs & Stratton engined generator has a catalytic converter (apparently now required for CA) and a small carb but I think that works well as it's a narrow range engine- constant RPM, not a particularly variable load.

Lada used carburettors and catalytic converters through until the 90's, with enevitable problems as the carbs wore and got out of tune. They moved onto computer controlled SPI after that.

That being said, with the right setup and good conditions it's possible to "clean up" an engine- friend of ours had a 1977 Ford Fiesta with a 1.1 litre Kent engine, and a small Solex carburettor, mechanical CB points etc and it ran cleaner than a lot of cars WITH a catalytic converter, well maintained, with readings that had the tester check his machine on a few other cars to make sure it wasn't broken.

Best bet on an engine of that vintage would be fuel injection that can be mapped on a rolling road, to aid a 14:1 burn- but then factors like plugs and valveseats become an issue as you may end up burning the fuel hotter than designed (weaker mixture), especially with today's unleaded+ethanol.

I'd say go for it though, get the car running a good mixture and fling a couple cats on it, as close to the engine as possible to keep them hot.

Totally possible, and it would mean that "hulking dinosaur" need not be "scrapped"

--Phil

[4more]

hello more of a lurker than a poster but i like this topic
If I'm correct converters came factory on cars in i believe 1976 +-
fuel injection came on cars full stream 1986+-
also i have heard of many people with older cars getting 20 plus mpg with 6cyl.
and Hot Rod mag. got a 67 Camaro they saved from the crusher in 1993 and got it to pass Cal. emmisions.
1967 Chevrolet Camaro Drag Car - Hot Rod Magazine

[rmcelwee]

There are a lot of old unused cats laying around. You could just pipe a couple up on the exhaust and see what happens. Probably wouldn't cost that much (assuming you can weld) and you would get to actually see what happens instead of just guessing.

[bikin' Ed]

If you can just "pick up" a 1964 Chevy you're either very wealthy or very lucky. They are in great demand. I'd restore it and sell it. Somebody will keep it, mostly in the garage, and it won't pollute and will burn hardly any fuel. The $$ you make could go a long way!

[Ang84Indy]

I think it's a great idea. I would install a fuel injection system that uses O2 sensor, get it tuned properly, then add the catalytic convertor (to avoid damaging it during set-up).

[Superturnier]

I have been dreaming about this same idea for some time, since I don't like either so much the smell of exhaust fumes. And as my old summer vehicle is not so leak tight, some of the smell comes inside the car.

Anyhow I think that the ignition system should also be in good condition to avoid unburnt fuel entering the cat. The fuel in the cat would cause excess heat that can melt the cat.
To minimize this risk of melting I would put the cat more far behind from the engine.

I'm not so sure if the A/F mixture has to be exactly right because also the newer cars run rich when cold and that does not kill the cat immediately. It just doesn't clean all the pollutants 100% Or what do you think?

Well these are just my thoughts, I cannot be sure since I haven't tested it.
Maybe next summer

[Trackerrrr]

Originally Posted by bikin' Ed

If you can just "pick up" a 1964 Chevy you're either very wealthy or very lucky. They are in great demand. I'd restore it and sell it. Somebody will keep it, mostly in the garage, and it won't pollute and will burn hardly any fuel. The $$ you make could go a long way!

You can pick up 4 door models pretty easily out in SoCal that don't cost a second morgage.

[Cd]

Why not just look for one with a transplanted 350 with modern day components ?
Even if you find one that has a 350, but it has a carb, you could convert it using pieces from a junk yard.
Cars from that era had horrible aerodynamics, but a large portion was due to the underbody.
You could probably drop the drag down quite a bit with a stealth belly-pan and still have the classic look of the car.

[Frank Lee]

The upper bodies were awful too.