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Smokescreen?

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SaxMan

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I couldn't resist the 70 degree temperatures today and despite the road being a bit sloppy from melting snow, I just had to take Baby Blue out for a top-down run with my daughter in tow.

Coming down a mile long downgrade with the engine in 4th and off the gas, when I got back in on the gas again, I left a HUGE cloud of blue smoke. The only factor that I know was the the carbs were mixed overly lean, but that shouldn't give you blue smoke. I'm thinking valves or rings? I'm probably not going to do anything about it right now: The engine still feels stout and oil is cheaper than a valve job / ring job / rebuild? At some point, though, I do know this motor is going to need an overhaul.

The car does seem to have developed an appetite for oil. I know that I'm losing oil through the main seal right now, but I'm pretty sure I'm burning some through the tailpipe as well. It leaked / smoked through 3/4ths of a quart in a bit over 200 miles.
 
I think you're on the right track with the valves. Around here that would be about a $400 job for new exhaust seats and guides and seals.
 
Having a similar situation with my '66 Land Rover and its 380,000 + miles on the engine. It really shows up in warm weather and has diminished this winter. If it were valves themselves it would happen all the time, so I'm thinking valve seals and I second the suggestions made above.

Jeff
 
If I was going through the trouble of installing new valve seals, I'd go ahead and do the whole head. The last time I did just the seals (using the rope trick to hold the valves up), the head gasket later failed (about 800 miles later). I suspect the removal of the rocker assembly had something to do with it. I guess you could do it without removing the pedestals, but if the head has never been rebuilt ... might as well bite the bullet. The seals can only do so much if the valves are dancing around in the guides.
 
You can replace the seals leaving the rocker shaft and pedestals in place so you don't compromise the head gasket. However, in my experience replacing the seals without dealing with the valve guide wear is a temporary band-aid at best.

You can see some of the details of what I did at the bottom of my friend Todd's Austin America web site. I don't know if he still sells them, but Todd used to sell the nice blue Viton seals shown on the page linked below. (Scroll down to Cylinder Heads & Oil Consumption).
https://members.tripod.com/austin_america/id82.html
 
When I took the rockers off to replace the seals I was a newbie to the A-series and didn't realize I was loosening the head. A few minutes of head scratching would have avoided the mistake. However, once I had to pull the head and saw how sloppy the guides were... I realized that the seals and the bit of smoke were only minor problems comparatively.
 
I took Baby Blue out for some exercise at dusk this evening, knowing that the weekend is going to be a wash-out in Maryland. With the exhaust illuminated by trailing car headlights, I seem to have the opposite problem. When I launch from a stop, the car leaves a pretty massive smoke screen, but it goes away when engine speed increases. It was definitely far more prevalent and noticeable when the engine was colder. Once I got about 10 miles of driving, it was still there, but not as bad. I had recently adjusted the valves, so I'm not sure if this is a fuel/air mixture, or if I am blowing oil past the rings...or maybe I need to recheck my valve adjustments? I never saw the smoke during daylight.
 
The problem with a fresh head on a worn ring/cylinder is it will cause oil to be draw past the rings. No sense in doing the head for oil burn unless you at least to a re ring.

What weight oil do you use? Some VR1 straight 50 and half a bottle of Lucas oil treatment will work wonders for old oil burning engines. It's not exactly a cheap oil change but it will get you though a season at least maybe more.
 
I use Castrol 20-50. I can try the Lucas treatment. Sounds like the bottom half of the motor is going to end up being next winter's project.
 
Maybe you should get a bumper sticker that reads "Stay back 100 feet. Smoke screen button is stuck."

:playful:
 
SaxMan said:
I use Castrol 20-50. I can try the Lucas treatment. Sounds like the bottom half of the motor is going to end up being next winter's project.
Click to expand...

I use 20/50 in winter and straight 50 in summer. You can always tell folks the smoke screen is part of the James Bond package. :eagerness:
 
Lucas oil treatment will delay an overhaul quite nicely. A friend who is apparently too lazy to overhaul his MGB has been running on it for years!

Kurt
 
Quart of oil $2.00, engine rebuild $2500. Do the math. Easy for me to live with just as it is. Bob
 
I guess it's like they say...before driving a Sprite, make sure you check the gas and fill it up with oil.
 
Funny Billy I thought of you first also. :grin:
 
I picked up a bottle of the Lucas Oil Treatment tonight. Boy, that stuff is like glop! I opened up the oil cap, inserted the bottle like I would a typical bottle of motor oil, went back a few minutes later...and barely anything came out! I had to squeeze the bottle to empty the contents. We'll see what happens to the smokescreen.
 
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