I haven't thought about this much, but I might as well throw it out here and see what you guys say. I wouldn't mind having this "fixed."

The Chevelle runs fine, doesn't really have any issues I'm aware of. However, when you're driving it around on the street, and coming off from a stoplight and you nail it good and keep your foot in it, you can see what looks like oil smoke behind you. It's not super thick, but you can see it.

On the track I've videotaped my brother launching any number of times and have never seen this happen, and that's with him engaging the clutch around 5800rpm.

I wouldn't mind getting that smoke thing eliminated. It makes the car look a little junky...uh, junkier!

Motor was rebuilt a couple years ago and can't have more than 10K on it. Total rebuild. Heads were new, never used Vortecs at the same time.

Do I have a PVC problem going on? There is a valve plumbed into the passenger side valve cover.

Tire smoke?

Carbon blowing out from too much street driving with a rich carb?

No, it wouldn't be tire smoke. I'm not hazing the tires.

However, you could be on to something with the "too rich" scenario. I can't seem to get the hang of this carb tuning, or the ignition for that matter! It's a wonder the thing runs at all, let alone turning in great ETs! Guess you just get lucky sometimes.

Like my dad once said, "God looks after fools and little children."

I had a similar problem about a month back. Your situation may be different, but mine turned out to be a leaky tranny pan. Under pressure, it was shooting fluid out onto the exhaust when I nailed it. My pan bolts needed to be tightened. Hope your problem is this simple!

Good thought, but it couldn't be that easy - 4spd car!

make sure you have your timing dialed in before you mess with the carb
sometimes the valve seals tear on a high lift cam
might take a peek next time the covers are off

Yes, the thought on the valve seals had occurred to me. Should maybe pull the covers and look.

I'd guess the secondaries are a tad rich. Try leaning them a couple jet sizes and see what happens. Is the smoke black (fuel) or gray (oil). If gray, working on the carb won't help.

The smoke is rather light, and it's pretty darn hard to tell what color it is by looking in the rear view mirror.

I can't change the secondaries, as they aren't the adjustable type. I hate that.

I also have a similar problem, black smoke. I was told it's probably my vavle seats or vavle guide/seal? I know my carb is in bad need of a rebuild, so that is also a great possibility. Good luck! graemlins/beers.gif

Originally posted by TH:
I can't change the secondaries, as they aren't the adjustable type. I hate that. TH, after looking at your site, you have a Holley w/ Vac secondaries? All of the vac secondary Holleys I ever worked on have a metering plate that comes in different jet size equivalents. Summit has a good selection of these plates.

Could it be just combustion residue that accumulated in the exhaust?

tpshea,
Thanks for the tip.

The carb is rebuilt.

von,
I suppose that's possible. I guess one of the reasons I wonder about it is because it smells like it's running on the rich side. Phew!