Any ideas on what's going on?

[Naco1]

What's happening ratsun!? ok so im finally done buttoning everything up. Here's the checklist of the things ive replaced.

 

new webber carb.

hooker super comp header

changed oil with 20w50

ngk plugs and moroso wires

new coil

and just redid the exhaust to a borla muffler.

 

now the first video is first start up after installing everything, running open header.

 

http://www.youtube.com/watch?v=A-1P7K7oOnU

 

the second video is after the exhaust got welded on.

 

http://www.youtube.com/watch?v=UcKDiD_nWgk

 

thats a lot of damn smoke. I noticed the smoke after i did the exhaust and changed the 10w oil to 20w oil. After i noticed the smoke I threw in some seafoam to clean any excess carbon, now i know seafoam is supposed to make smoke up the tailpipe but this smoke filled the driveway up. I know what oil smoke smells/looks like and i know that aint it. Temp is at 195-200 and oil presure is at 50, rpms at idle 850. Any ideas on what this smoke is?

[Laecaon]

Coolant? that can burn white... My thunderbird made huge clouds when it blew the head gasket, 1 cylinder was so wet it wouldnt fire anymore.

[Naco1]

i just did a coolant flush with new coolant, my temp gauge doesnt show any over heating. The smoke isn't steam like, its more like a thick fuel smell.

[datzenmike]

Run it for a few hours to burn it off. Myself, I wouldn't run that shit in any motor.

[Naco1]

damn a couple of hours? ill take it on a long drive tomorrow. Anything i should know about this seafoam stuff? it came highly recommended from a buddy of mine.

[flatcat19]

Now if you're smoking, why would add other stuff that makes it smoke more?

 

Burn that Seafoam out.

Go back to 10wAnything else.

Remove plugs, look for water.

Adjust carb.

 

Also, new ignition coil, wires, and plugs could be burning off years of excess carbon.

 

 

[xxmass]

did it smoke like that before the seafoam?

[datzenmike]

I have no doubt seafoam removes carbon. Carbon gums up the valves but also helps seal the rings on old motors and control oil getting up into the combustion chambers. If your motor is running properly you shouldn't have too much carbon build up anyway. Removing all the carbon or loosening it may allow a small loss in compression and an increase in oil consumption. In other words this stuff can't work miracles on a truly worn out motor.

 

Ever seen the piston tops of a motor with a blown head gasket that's had coolant water get in? That water has turned to steam on the hot pistons and combustion chamber and blasted the carbon off.

 

If this is an old motor I wouldn't go down to a light weight 10 W anything unless you expect to drive in 0 F temps.

[kelowg]

Loose manifold bolts. Did u replace the manifold gasket when u put on header? Tried samething once without new gasket and thats what happened

[datzenmike]

The header is likely to smoke also till what passes for paint on it 'cures'. Give it some time.

[Naco1]

Yea it was smoking before the seafoam, replaced all gaskets, I know for a fact this engine has quite a lot of miles that's why I went with a thicker oil, I thought a 10w would be too thin. I'm going to try to drive it for a couple of hours and lets see what that does. Also going to go over everything just as a precaution. Thanks again guys

[Dat Lurka]

IMO

if you know it's got over ~160

Get a timing kit, gasket it, and get the head machined.

Or rebuild the thing while it's still cheaper than dirt.

 

rockauto.com under 77 datsun 620

 

http://www.rockauto.com/catalog/moreinfo.php?pk=1814646

 

334$

 

I don't know why they don't have rebuild kits listed for earlier years.

 

If you bore the cylinders just email the service department and they will send you the pistons you need.

[Naco1]

Ok. Just did the compression test.

 

1. @170

2. @175

3. @180

4. @175

 

Hmmmm. Is that good compression?

[datzenmike]

Very good. Have the valve seals been replaced?

 

Is it over filled with oil? A little over 4 quarts with a filter?

[Naco1]

Oil is perfect. On the money. I know the head has been removed and surfaced because of the Nissan letters on the side of the block are shaved a little off if that means anything?. The previous owner confirmed it but don't know about the valves. Any particular way you vent the head? Breather or directly to carb?

[datzenmike]

The valve cover vent pipe goes inside the air filter. That's between the filter and the carb. When blow-by exceeds the PCV's ability to handle it, it backs up and out the valve cover vent pipe and is sucked into the carb and burned in the motor.

 

The Valve seals can be changed without taking the head off and without any special tools, well...a spring compressor.

[Rays74]

That is great, even compression across the cyl but there could be a slight chance that you have a broken oil ring in one of them. Only seen it happen a few times in all the yrs but the symptoms are very similar to what you are going through :(

[Naco1]

Ok so I ran the seafoam out and I guess it cleaned everything out real good, now I have oil coming out of my tailpipe. I stuck my finger in the tailpipe(giggity) and My finger came out with black wet oil. Craaaap! So. Yea, what now?

[Dat Lurka]

Ok so I ran the seafoam out and I guess it cleaned everything out real good, now I have oil coming out of my tailpipe. I stuck my finger in the tailpipe(giggity) and My finger came out with black wet oil. Craaaap! So. Yea, what now?

 

 

IMO

if you know it's got over ~160

Get a timing kit, gasket it, and get the head machined.

Or rebuild the thing while it's still cheaper than dirt.

 

rockauto.com under 77 datsun 620

 

http://www.rockauto.....php?pk=1814646

 

334$

 

I don't know why they don't have rebuild kits listed for earlier years.

 

If you overbore the cylinders just email the service department and they will send you the pistons you need.

[flatcat19]

When you did a compression test, Sid you do it dry and wet?

Cylinder difference next.

 

GL.

[Naco1]

Wet

1.@ 160

2.@. 175

3.@. 165

4.@. 160

 

[flatcat19]

What were the numbers dry?

[Dat Lurka]

whoa...

[Naco1]

1. @170

2. @175

3. @180

4. @175

[Dat Lurka]

Jeeze I thought L20s were ~150