mazdaverx713b

iTrader: (91)

since i am new to the pre 81 style emission system, i was curious what the purpose and function of the heat exchanger in the exhaust sysyem is. i am aware of the function of the thermal reactor thanks to a prevous thread and the responses i have gotten.

mazdaverx713b

iTrader: (91)

anyone???

Wankelguy

The heat exchanger heats the air that is injected into the exhaust ports.

mazdaverx713b

iTrader: (91)

outstanding, thank you Wankelguy! if that goes bad, where can it be bought new?

Critoris

There's a baffle in the snorkel of your blue airhat with a bimetallic clockspring underneath. When it's cold, that spring closes the baffle so the intake air is drawn up through the flex-pipe from the heat exchanger. During cold weather, the car always breathes through the heat exchanger so the carb sees more uniform air density year-round.

Critoris

I think Mazda was embarassed by how small their little 12A was so they added ALL KINDS of crap to make the engine bay look more busy. You don't need it, even up by the great lakes. That and the subzero start assist are two tremendous wastes of space, unless you want badly to keep it original.

Dom

Without that warm air inlet, the carb freezes up in the winter, and the car slows to a crawl.

I know from experience since I had it removed on my chevette (small c) when I got a chrome air filter holder. I was just a young punk then.

Critoris

Well, I've never had an issue of carb icing. I guess when in doubt, leave it, but I've had no troubles.

Wankelguy

Are you talking about the carb pre-heater hose that is attached to the thermal reactor's heat shield?
That has nothing to do with the heat exchanger.

Cody

I'm all confused. I thought heat exchanger was when you had a huge hole in your hood to allow heat to escape.

Now you're talking about a pre-heater hose, and some exhaust crap.

Oh great, now I have a headache.

Critoris

Anything that convects heat from one fluid to another (air is a fluid) is a heat exchanger. The carb heat system uses the exhaust manifold as a heat exchanger. Your A/C evaporator AND condenser are both heat exchangers. Your oil cooler, radiator, intercooler ...., hell, your differential cover... all heat exchangers. If I'm on the wrong page, fine. But my car doesn't have anything else that might commonly be called a heat exchanger.

mazdaverx713b

iTrader: (91)

no, there is in the exhust system, a piece that resembles a catylitic converter. in the fsm, it is described as a "heat exchanger". it has a tube running off of it. up to i think the thermal reactor. i was not really sure of the function of the heat exchanger.

Wankelguy

Yes, that's the heat exchanger I'm talking about also.
The tube runs up to the rearward part of the intake manifold.
Why do you think yours is bad?

mazdaverx713b

iTrader: (91)

no, i do not think so. car runs perfect. it should with only 56K on it. i was just trying to gather all of the info i could on my vehicle and it's systems. once i was new to my 84 gsl-se. now my 80 ls. heck when i bought my first 7 back in 99, i didn't know very much at all. all of the manuals, even the fsm i have don't go into detail about this part. i am trying to learn so i can maintain my car properly and know how to fix anything.