Unusual pipe bluing
- Thread starter dblair
- Start date
Mike
Well-Known Member
I split this post off into a unique thread, so we can keep questions and subsequent responses separated for each member's issue.
@dblair , have you check all 8 primary tubes with a heat gun? If the plugs do not have a lot of idle time on them, they might give you a clue as to what is happening.
What intake/carb setup are you using, as you may have some distribution issues going on.
@dblair , have you check all 8 primary tubes with a heat gun? If the plugs do not have a lot of idle time on them, they might give you a clue as to what is happening.
What intake/carb setup are you using, as you may have some distribution issues going on.
Using a complete set up from edelbrock. The motor is a 327 64 thru 67 bored 60 over. The manifold is the performer rpm 1500 to 6500 . Cam is a package # 7102 with hydraulic lifters. Double roll timing chain. The only thing I did not buy from edelbrock was the 600 cfm dual plane w egr with electric chock with square flange. Brought it from local napa store. I also noticed that when I turn in fuel adjustment all the way it seems and wants to stall or run rich. If I turn in air adjustment nothing happens. I blew out both air and fuel adjustments but still the same. I also don't show any vacume on guage at idle but have steady vacume when running at about 1000 rpm . It seems that everything I have is the right set up for that motor but just so confused . Thanks to all
Since it sounds like you have an idling or running issue, maybe we can cure both. First, describe where the air and fuel adjustments are located on your carb. I do not do much with Edels, but am sure we can work it out. I am going to google the carb and get updated.
James C
Member
Have you confirmed the one that is not bluing is actually firing? Pull the plug and make sure it sparks? If it does than run the engine and squirt water on all the header pipes individually one at a time with a squirt gun. Does it boil off the non blued one like it does the others?
Hotrod46
Member
OK a couple of observations. First, if you have the vacuum gauge connected to the ported side of the carb, you will have little or no vacuum showing at idle. If, on the other hand, you do do have it connected to constant or manifold vacuum port and have no vacuum at idle, then I would suspect a large vacuum leak.
Also, from your statement, I can't tell if you have an EGR manifold or if the carb is for an EGR application. If the carb you bought was jetted for an EGR application , then it would have leaner jetting since the EGR replaces some of the air in the FA mix with exhaust gas. Running it without functioning EGR (or rejetting it) would cause a lean condition.
Retarded timing will cause bluing.
Any of the things I listed would drive exhaust temps up and cause pipe bluing.
FWIW, I have been running chrome pipes for 6 years now with minimal bluing. There are a couple of pipes that are blued, but I'm sure that's due to the old 3X2 manifold having distribution problems. Your later designed Edelbrock should have better distribution. I don't consider bluing on pipes to be normal.
old round fart
Well-Known Member
When I built my car I wanted a rich mixture to cut down on the bluing so I drilled all my jets with an 1/8" drill bit! Hey! I didn't know any better and gas was .30 cents! They blued anyway but I never lost the motor.
You have to read into the post to evaluate the level of engine tuning aptitude to properly relate issues. I do not think there is an air and a fuel adjustment on an edel carb, so we are getting oriented first. What I think is happening is one idle mixture jet is being identified as fuel and the other as air. When we get the carb idle mixture adjusted we can see where we are. It would be about like Mike trying to tell me something about computers. Believe me I know what I am doing, I saw a guy do it in a commercial one time.
Mike
Well-Known Member
There isn't. It uses idle mixture screws to determine the flow of emulsion, same as any other carb.
And yes, I prefer to adjust mixture screws with a vacuum gauge, rather than adjusting by ear.
Thanks all, a lot of good things to try. I did find out that the carb is 600 cfm duel plane w/egr. and the manifold is a non egr . I will be doing another vacume test on manifold ,look at spark plugs and do compression test. And yes they are idle mixture screws my mistake. Thanks again //
If one of the idle mixture screws is unresponsive, you probably have some trash in the carb, a vacuum leak or a fuel delivery problem.
What kind of fuel pump are you using? Make sure all the ports and fittings are plugged or attached on the carb and intake. If you would not mind, post the part number for the carb. I would like to see what is involved with the egr model. It could take a different base plate gasket or require an adapter for a non egr manifold.
What kind of fuel pump are you using? Make sure all the ports and fittings are plugged or attached on the carb and intake. If you would not mind, post the part number for the carb. I would like to see what is involved with the egr model. It could take a different base plate gasket or require an adapter for a non egr manifold.
Screaming Metal
Active Member
Sitting on the fence here, with my stogie and my coffee....I hear the Jeopardy music playing in the background....
Oh, Childern, don't try this at home, and do not wear blue shades while doing this....
INFO! WE NEED INFO....
While your doing what they said....also, make sure those 2 cylinders have the same plugs ....
Oh, Childern, don't try this at home, and do not wear blue shades while doing this....
INFO! WE NEED INFO....
While your doing what they said....also, make sure those 2 cylinders have the same plugs ....
Last edited:
Sitting on the fence here, with my stogie and my coffee....I hear the Jeopardy music playing in the background....
Oh, Childern, don't try this at home, and do not wear blue shades while doing this....
INFO! WE NEED INFO....
While your doing what they said....also, make sure those 2 cylinders have the same plugs ....
The carb part number shows an economy tuned replacement carb for GM factory engines. This will not be too bad if you are competent in disassembling and tuning Edelbrock carbs. There is a possibility you have a vacuum leak, the carb is not adjusted right and you can get it in the ball park of running OK.
If you want to work with what you have, start by following the procedure of adjusting the idle mixture screws, in the video Mike posted.
If you will put your vacuum line on a manifold vacuum port, you can use it to aid in the adjustment. The port needed will have high vacuum at idle. Plug the unused port.
If you want to get the right carb, I will defer to the Edelbrock users on here and let them recommend something that is working good for them.
If you try the carb adjustment, get back to us and let us know how it went and what you encountered in the procedure.
I will look up the cam card to get an idea of what kind of idle you should have. Let us know how the car idles, rpm, vacuum reading and tip in throttle response. Be confident, sounds like a nice engine.
11 inches of vacuum at 1000 rpm. The cam is going to have some chop to it. If you can swing it, I think you will be better getting another carb.
If you want to work with what you have, start by following the procedure of adjusting the idle mixture screws, in the video Mike posted.
If you will put your vacuum line on a manifold vacuum port, you can use it to aid in the adjustment. The port needed will have high vacuum at idle. Plug the unused port.
If you want to get the right carb, I will defer to the Edelbrock users on here and let them recommend something that is working good for them.
If you try the carb adjustment, get back to us and let us know how it went and what you encountered in the procedure.
I will look up the cam card to get an idea of what kind of idle you should have. Let us know how the car idles, rpm, vacuum reading and tip in throttle response. Be confident, sounds like a nice engine.
11 inches of vacuum at 1000 rpm. The cam is going to have some chop to it. If you can swing it, I think you will be better getting another carb.
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