New To The Site. Blue Smoke Issue.

Greetings to all ! Been lurking and learning and appreciate all the knowledge. I'm wanting to make my 1963 CJ5 right and need some ideas.

I've owned mine 16 years and it's smoked since day one. I never drove it much, all off road hunting so i didn't care about it smoking. I want to make it street legal, drive it, maybe sell it, but the smoke ain't right. It blue smokes all the time it's running, big clouds when rev'd. J8 spark plugs (all) will turn sooty, not flaky, very quickly. I've not run it long enough to foul but think they would. Cannot street drive yet so hard to say oil consumption.

What I've done.....
Tuned up, F4 134, btw. Runs very smooth with good acceleration (good being relative ;-)
Isolated and cleaned PCV, working well. Blue smoke even without PCV and line attached.
Isolated air cleaner, smokes.
Changed oil twice. Was 30w, now 15-40, no difference. Added "stop smoke", (just to see) same smoke.
Compression test good. 132, 132, 128, 122.
Vacuum test, 18'ish, no flutter.
Pulled valve cover to check for sludge blockage.....very clean.
Adjusted carb, lean out, rich, same smoke. Smoke is blue, not black, but I thought "maybe".

Maybe valve oil seals forgotten or disintegrated? Don't know rebuild (if at all) history. Can it be the rings with such good compression? Rings installed wrong? Sources for oil I'm missing? Fuel pump has no vacuum lines attached (I guess that's what those 2 barbs are for)

What would you suggest next to diagnose?

 

Blue smoke always meant head gasket in my experience. A lot, or little of smoke?

 

My experience has always been blue smoke = new rings (and/or boring and new pistons). You should rerun the compression test to confirm results and then squirt about a tablespoon of motor oil in each cylinder and rerun the test again. If the compression goes up with the oil, probably rings. If it doesn't change, look at the valve seals. In my experience, a blown head gasket usually produces white smoke.

 

It's quite a bit. Every now and again, on start up, it's light but always ends up puffing really good on rev ups.

 

Thanks, I'll give that compression retest a go! Radiator water was clean and full, so I'd ruled out head gasket. Would be nice if it was that easy.

 

Checked the tips of your spark plugs for burnt oil deposits? This may tell you if the situation is coming from a particular cylinder.

Does your engine have a vacuum pump? Was it disconnected from intake manifold vacuum when you "isolated the PCV?"

For whatever reason, I've had a lot of broken rings and scored cylinders in my f-heads.

 

I think we can lay most of the blame for that on the 4 3/8's stroke and pretty soft iron blocks. A lot of piston acceleration/deceleration. I don't know if I ever got more than 60 to 75k miles out of a bore/ring job. But I know some of that was likely due to farm service with short run times.

 

I've often wondered if it was also because many jeeps around here were only used seasonally... maybe rings get rusted or stuck over the winter? Dry cylinder walls on Spring start-up?

 

All the plugs are "wet" with dark soot, not so much the tips and ceramic but elsewhere.

 

It does NOT have a vacuum pump.

 

I agree completely. Seems like they are a magnet for condensation. The thing is, mine isn't smoking any worse than it was 16 years ago. That being said, I probably only put 200-300 miles in all those years.

 

As suggested, I'm going to retest the compression with oil in the cylinders to see if it boost compression numbers. It measured 132-122 dry, so I assumed it wasn't the rings. It'll be a much cheaper fix if it's valves only.

 

Welcome from Ga.

 

And you'd be correct.......I ran the dry (again) and then the wet. Here's what I got:
DRY: 132, 132, 125, 125
WET:138, 140, 135, 135

Is that difference dramatic enough to determine the rings are causing the constant smoking issue?

 

I don't think I've ever seen compression numbers that good on any f-head of mine.

My '56 smokes quite a bit and burns oil. But it runs okay and I reckon oil is cheaper than a rebuild.

Going back to your original post, you said the plugs were sooty, not flakey. Soot is usually from an over-rich fuel mix. An oil-burner will have crusty deposits, possibly oily, but not sooty.