Puffing Smoke

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321Scamp

321Scamp

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My 74 318 has 2" duals, a mild cam, not sure what it is but it is not stock, bore over to 321, and a 600 Edlbrock 4bbl on Edl. intake. I can't seem to find the right mixture to keep it from puffing out white smoke at the hit of the gas after sitting for a while. That and it runs just a little on the rich side. Any suggestions?

Thanks

74 318 Scamp
04 QC 4.7 Dakota
 
Edelbrock recommends turning the screws clockwise until the idle stumbles, then backing off 1/4 turn. Is this the method you are currently using. Or you can hook a vacuum gauge to manifold and find the highest reading while making the adjustment.
 
White smoke is an indication of water as in condensation or a blown head gasket. Your description of when you get the smoke sounds like oil is leaking past the valve guide seals but that should have a blueish/grey color. Smoke from an overly rich condition is black.

If you are running rich enough to create smoke the plugs should be covered with black soot. I would check the plugs if the side electrode is tan to brown along with the center electrode ceramic then you are not rich.

My guess is the valve guide seals. These can be changed with the heads on the engine, you will need a way of holding the valve in place (compressed air or a piece of rope shovedinto the cylinder via the spark plug hole) and a spring compressor.

If the carb does need tuning I would suggest getting a book on tuning Edelbrock carbs. I picked up one on Holleys years ago at Borders or do a search on Amazon.
 
I'll try the adjustments on the carb. The smoke comes more in the mid RPM range. You can realy notice it when in park and reving it up. Just driving it is not as noticable. It does have a lot of moisture and black soot in the tips. I am running 93 gas, I ran 93 with NOS Oct. booster and did not notice smoke and ran a little smoother. Could it be bad gas quality?
 
321Scamp said:
I'll try the adjustments on the carb. The smoke comes more in the mid RPM range. You can realy notice it when in park and reving it up. Just driving it is not as noticable. It does have a lot of moisture and black soot in the tips. I am running 93 gas, I ran 93 with NOS Oct. booster and did not notice smoke and ran a little smoother. Could it be bad gas quality?
Click to expand...
When you hook the vacuum gauge up is it low? If so you may have a vacuum leak. I had a similar problem with smoking while revving at idle (but from the passenger side only). So I took carb cleaner and sprayed the base of the carb and the intake manifold where the ports lined up. Sure enough, the RPM's kicked up by a few hundred cylinders 5 & 7. It was sucking oil into the cylinders. Also, it just happened that the spark plugs in these 2 cylinders were oil fouling. I just replaced the gaskets, along with a new mainfold and the problem has gone away. Hope this helps.
 
It does not burn off any oil. After futher inspection, it is just running way to rich. The white smoke is moisture mixed with fuel. I am going to up the heat range in the spark plugs from a Champion 14 to a 12. A 340 uses the 12 so it sure work just fine. I know I am throwing enough spark with the Axcel 8.5 wires and SS coil with Mopar Orange box. Also, I am looking at rejetting the carb. It is the 1406 Edelbrock. I runs just way to rich for my car.

Thanks again for all your input, keep ya posted on progress.
 
I am running a .035 gap. What size gap should I use with the #14?
 
321Scamp said:
I am running a .035 gap. What size gap should I use with the #14?
Click to expand...

gapping is 0.035 for RN14YC
gapping is 0.035 for RV17YC

your car calls for a RN14YC.. theres no real reason you should be going to a hotter plug.. if your needing a hotter plug you have other problems.. and i checked my champion plug catalog.. it only goes to RN14YC for V8's and RV17YC for L6's which have different size plugs and depths. fyi

cerwin
 
All right.... I finally figured it out. After checking everything one more time, I found that my timing was all out of wack. It was so far before TDC, you could not even see the timing mark. Then I check my plugs and they were severly fouled. I went and got replacement plugs, #14's again, at NAPA where my brother works and he pointed out that the gap was at .040. Don't know why it changed but it was .035 when I put them in, I thought. So a couple of small things causing big problems. Now that it is tuned better, it will be interesting to see if I will get better than the 17 MPG that I was getting.

Thanks again for everyones input, it gave me plenty of things to check.
 
321Scamp said:
All right.... I finally figured it out. After checking everything one more time, I found that my timing was all out of wack. It was so far before TDC, you could not even see the timing mark. Then I check my plugs and they were severly fouled. I went and got replacement plugs, #14's again, at NAPA where my brother works and he pointed out that the gap was at .040. Don't know why it changed but it was .035 when I put them in, I thought. So a couple of small things causing big problems. Now that it is tuned better, it will be interesting to see if I will get better than the 17 MPG that I was getting.

Thanks again for everyones input, it gave me plenty of things to check.
Click to expand...


I work at napa.. Great place.. Where does your brother work?
 
He works at the NAPA in Knightstown, Indiana. He is an A body owner too. He has a 75 Duster /6. Dad is the only one with out an A body, he has a original sublime 70 Challenger T/A.
 
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