Your opinion on this pic, please

[Danskman]

'80 SC, looking at the crossover pipe that connects to the cat converter. I am quite puzzled by the vastly different colors of the two incoming pipes. Bottom one is from the left bank, and appears very, very lean. To me, almost dangerously lean. I've never seen anything so white before on an exhaust piece. I would consider the top one fairly normal. Can those of you who've seen lots of these in a tear down please comment? Thank you.

[Danskman]

bump

[dickster]

can't comment on that specifically, but why not just pull the plugs on the "lean" side?

[Rick Lee]

That might be more of an issue with the gaskets. Plugs are the way to really tell.

[makaio]

Like Richard and Dick said, check the plugs.

[RickM]

Looks like one flange was better protected from outside contaminants. I'd say it's a gasket/sealing issue.

[Schrup]

Dude, why would you paint the inside of your exhaust? Nobodys gonna see it in there.
Do you have alot of decel popping? I do & I wonder if I have a leak & if mine will look the same. All my plugs looked great when I changed the a couple months back.
What kind of paint did you use?

[RickM]

Reread and see you're questioning the inside of the pipe.

Ooops....

[Savage]

Over the summer I ended up doing a transmission rebuild. The pipes looked the same. How do your plugs look on that bank of cylinders?

[dfink]

When I first saw the picture I thought a styrofoam coffee cup was stuck in there.

[Wayne 962]

I think it's related to how the heat is distributed. The one below will probably be hundreds of degrees hotter since it's closer to it's source. The cross-over pipe acts as a cooler. I have seen the white hot residue thing before when things get really hot.

Since it's not a tuned, matched system (lengths/diameters), I don't think any definitive conclusions can be drawn here...

-Wayne

[Eugene at Pelican Parts]

I'm not sure, but I might have a similar picture from my car. If I find it, I'll post it so we can compare. Mine was definitely not white at all.

Edit: Oh, and regarding your suspicion of a lean condition, I would think it's the opposite. I agree that you need to check your plugs first, but if it's white due to a hot burn, you're running rich because fuel shouldn't be igniting in your exhaust at all. Was this with a catalytic or a bypass pipe?

[Doug Zielke]

I agree with Wayne. One pipe is much closer (therefore hotter) to the cylinder bank than the other.