Need help with Carb.....

[The Icky Sticky]

Hello everyone!

I have a problem going on and can't seem to figure it out. I have a 78 Elky with a 350, approx. 315 hp. It has a Holly Street Dominator intake with an rpm range of idle to 7000 rpm. This is an emissions intake , so it has a spot on it for an egr valve. The EGR is not installed at this time. A blank plate is in its spot. It also has Doug Thorley Headers with a y pipe. Fairly mild motor.

This is what 's going on. When I first fired up the motor, I had an Edelbrock performer series carb (emissions) 600 cfm w/ elctric choke. Model 1400. I ran the motor for my guess is 10 minutes at max. I shut it down because the passenger side of the headers started glowing. And I mean GLOWING cherry red. Only the passenger side. I thought it would be a good idea to let the motor be for the night because I figured I might not even be able to start it back up since the motor was new. I talked to several people and heard 1) Sounds like a vacuum leak. 2) Timing is way off 3) Not enough fuel. Too Lean.

I just happen to run across another carb. I picked up a Road Demon. Nice carb!! Put it on my motor. Fired it up and the headers did not glow!! It ran extremely rich, so I jetted it down to make it driveable. Now its road worthy. I've put about 100 miles on it and have had a temporary moving permit to do so. Its a 78 so I still have to smog it. So I decided to put the Edelbrok back on because using the Demon will not get me pass smog. I put on, and the headers on the passenger side started to glow. I was told that if I had a vacuum leak, I would be able to here it. I dont here one. Also to let you know, the vehicle is running very smooth. Not missing or anything like that.

I guess I am going to get a new gasket for the carb for starters maybe it has a fine crack in it that I cant see. All vacuum hoses are new. Matter of fact, everything is brand new! If that doesnt fix it......Im lost.

Im really looking for suggestions if anyone can give me some.

Thanks!!

[enginerd]

I suggest you not re-build the carb. I would, in your shoes, replace it with a remanufactured carb. Emission-era carburetors are not friendly towards re-builders and are very complicated. I'd go and get another job to buy one before I attempted a re-build.

[The Icky Sticky]

So are you thinking the problem is the carb is ....." BAD " ? In need of rebuild? In your words replacement. Out of curiosity, what do you think is wrong with it?

Just asking for my own knowledge.

Thanks for the comments.

[enginerd]

I've seen internal cracks in carbs through magnafluxing them and it isn't too terribly common, but it sounds like you got one with a crack in it. If your other carb works fine on the engine, then the only thing that has changed is the carb. If one side is running lean, perhaps the jetting is incorrect/worn on one side. I do not know anything about a demon carb; I've never heard of them so all I can offer is basic knowledge. So my advice would be to take the carb to someone who could tune it or diagnose it-it may be expensive, but a bad carb can ruin a good engine.

[The Icky Sticky]

I called Edelbrok yesterday and they told me to replace the metering rods. He gave me a part number to use. I changed them and it semi fixed the problem. I think the next step is to re jet the carb now. Its actually driveable now. The headers are not getting hot like before.

Thanks for the suggestions, I think you actually hit it on the head in your last post. I will post what happens next.

Thanks again.

[enginerd]

I don't want to brag... but I've destroyed so many parts in not knowing what the hell they do, I've gotten quite an education! It's really expensive to learn these things and I don't want to hear a story about a dead El Camino!