glowing exhaust means what again?
 

ok i just picked up another rx7,
1984 gsl

and the first small cat glows bright orange,

i just cleaned out all the cats so there not clogged
i dont fuckin get it,

any help

i have the same thing with my dinomax cat at idle. freeking glow, looks like i have underbody lights, well not that bad. i think when the exaust glow like that is because the engine is lean, but i think too that is normal on rotary engine

It means you have a rotary.

Rotary's do run really hot but the engine should be run just a bit rich not lean, lean does = hotter and as such I suspect that the car should be adjusted a bit to see if you can get the exhaust temp down a little. they do run really hot and I know many after market hedders do glow some normaly.

Exhausts just glow when heated enough. I once got a Lotus torbo/exhaust maifold a lovely orange/white :)

Same thing happens to machine gun barrels.

Leaner than about 15:1 actually makes EGTs go lower.

You can't get a rotary to idle anywhere NEAR that lean. They normally start to misfire at about 13:1 when idling.

stop feeding the gerbils mexican dave.

if you run your carb to rich (to much gas) your cat will glow and you will burn it up. Thats what happened to me. I adjusted my mix down and have been fine since.

I had a header glow red one time, the problem was the dist. was a tooth off.

it was only running for 2 minutes tops,
i was just checking the belts

im pretty sure you got that backwards,
but i do think i run rich
maybe i will swap out my carbs again and see.

ohh..work work work

Does anyone here use header wraps or thermo blankets? I heard that they can cut down on the life of a header. But the steel they use on rotary exhaust is so darn thick, I have a hard time imagining that being the case.

O.K. dokey I might have an answer for you.. if you have a nikki carb like me,, :-( then it can be real sensitive to adjustment imagine taking a ruler and bending it in the middle. the curve you have is like the curve of the fuel richness and leaness on the fuel / air mixture screw located kinda in plain site on a 1985 gsl. now if you adjust it and you have trouble with misfiring, and or the cats start smoking out your eng compart obviously you've gone to far. I believe that a quarter turn from tight is factory default??? please corect me if i'm wrong. there is also an idle adjust screw damb near imposible to find when the engine is dirty. that can be fun to play with.. now if that doesn't help do yourself a favor and replace your intake gasket. laugh if you will but that can cause mis adjustments from humans, the engine with sputter, and becuase of the to rich mixture it will burn out the cats eventualy... peace

A glow after 2 minutes? that is something.

A new record. Heh, my friend's SA's cat glowed and smoked the underside of the car and center console when one of his rotors stopped firing due to a broken plug. It has a dellorto so you can imagine how much unburned fuel went into the cat. It's fine after getting new plugs.

Your friend's SA had a cat on it?

Yep, it has an engine from an '86, an interior from an '83-'85, power windows (say what?) and a dellorto carb with aluminum flywheel and RB disk/p.plate. Its nickname is Zippy! :D

:(

You're not happy with it?

If your cat is glowing, it means that it works. But also means its not going to last long since your mixture is far too rich and is near the capicity of the cat to convert all that raw gas.

Also, if its glowing at idle and when you are NOT driving it under heavy load/hard driving, it means you have a serious engine problem to deal with, bad compression that is allowing more then normal raw gas into the exhuast or bad carb/gunked up/maliadjusted, or a bad air pump/not on. You NEED to have that air pump or you will melt your cat on a rotary. The air pump supplies the cat with extra O2 to convert the unburnt HC's in a complete manner. Without the air pump, you will create more CO then CO2 which is a hotter reaction.

The only time I've seen glowing exhuast was on a water brake chassis dyno. I've seen V8's exhuast manifolds glow bright orange, and a mod'd challenger with glowing headers.. However I didn't see what my header was doing on the '85 '7 I dyno'd since I was in the car doing the throttling, I forgot to ask if anyone was looking.

i took the carb from my black rx7,.
it still has the factory cap on the mixture adjustment screw
i will take it off and play with it

brand new plugs

i had the choke open so it was @2,000 rpm
air pump works great,
i was playing with it and it was blowing my hair up on my head and thats how i really seent he glowing precat, "shhh dont tell anyone"

the air pump was blowing your hair up? if so then you must have taken the rubber hose off meaning it wasn't feeding the cat and it was turning red. or maybe i misunderstood that. the carb isn't tat hard to tune for idle. thought you were on top of this stuff dave. you've been to busy stripping and selling then tuning. :)

His cats are empty so the non airpumpedness shouldn't be an issue.