Black Smoke From Valve Cover Oil Fill Tube

[Fairlane Fixer]

I have blackish/blue smoke coming from my valve
cover oil filter tube only on acceleration. Engine makes
a rattling/clanging sound.

Could this be caused by dist. not advancing which
in turn does not burn the fuel correctly or fast enough?

Car lacks adequate power on acceleration with rattling
noise under load, smoke blowing out of oil filler push on cap,
but smooths out just cruising around 30-40 mph not under
as much load and torque load.

Maybe I have another problem.
___________
Thanks

 

[mugsy]

Same problem with my '65 Mustang, a puff of white/blue-ish smoke from the oil breather/fill cap. Ended up the rings were shot. The smoke come from the combustion in the cylinder(s) sneeking by the rings. OUCH!! I rebuilt mine.

 

[Fairlane Fixer]

Did yours make noise and lack power on acceleration?

 

[Anonymous]

Could be bad valve stems too ?

 

[simon]

right 76mav, could be the valveguides as well.

running a compression test (first without, then with some motor oil in every cylinder) will show whether its the rings or valveguides.
For those low on patience, a single test with some 10W30 squirted on each piston top will do ok.

 

[Fairlane Fixer]

Thanks everyone for their input.

I went ahead and removed the head.
Forgot to do a comp test. (Was in a hurry
to inspect if any damage)

Cylinders looked very nice. No scratches-
very smooth-clean shiney grayish. Does
not even seem to have a ridge at the top
of the cylinder.

Valves look normal black soot, no cracks, looks
fully seated, etc.

With valves fully seated, is it normal to be able
to twist the springs around with fingers? Seems
like they should be tighter. Are they bad? : :

 

[mugsy]

'76 Mav,

It would next to impossible for the smoke to be from the valve stems. If the combustion pressure was to get out of the cylinder it has to leak past either the rings or the valves. If I leaks past the valves then it would take the path of least resistance. So it would have to blow up thru the small difference between the valve stem and the valve guide OR back thru the carb!! My guess is the carb! And even at that, with the engine operating, another piston would be creating suction as that valve opened on the intake stroke. Again, not very probable for the smoke to come up thru the valve guide/stems.

Fairlane,
How easy it it for you to turn the motor over with the head off? Remember to put the tranny in Neutral. The easier it is to turn the more worn it is. I have my old engine out of the car and I can turn the crank over with one hand!!! The best way is to get an inside micrometer and measure in three spots (top, middle and bottom) of the stoke.

tanx,
Mugsy

 

[Anonymous]

I was just thinking that oil could be getting bye them and ontop of the pistons making it smoke . I wasn`t saying that the smoke was getting bye the valve stems though I don`t even know if that could happen.

 

[Fairlane Fixer]

Fairly hard to turn engine over. Takes both hands with adequate pressure.

I went ahead and dropped oil pan... WOA... a 7 bolt main.
Looked at engine # says C8DE (a 1968 block)

So now I have a #C3DE 1963 head & #C8DE 1968 block.
That's OK, now I have more to work with.

Anyway, Everything looked and felt great underneath.
But I noticed my timing chain is really, really floppy.
The gears were barely grabbing it.

Do you think this could be my main problem?
Cam may have slipped a tooth or more not
letting the lifters open the valves at the proper time
keep gases trapped inside and leaking up on the stroke
causing smoke and a sort of loud detenation noise under
higher RPM's and under load. JUST A THOUGHT

Later All,

 

[mugsy]

To find out about the spark knock, measure the CC of the 1963 head combustin chambers. Then measure the deck height. Go to the compression ration calculator on the Falcon Six web site and see where the CR stands.

Sounds like the bottom end is good condition, considering.

Mugsy

 

[Fairlane Fixer]

Computed CR to be 8.9:1

book says 63 stock = 9.2:1
Book says 68 stock = 8.8:1

 

[Fairlane Fixer]

Final unanswered question

Do you think this could be my main problem?
Cam may have slipped a tooth or more not
letting the lifters open the valves at the proper time
keep gases trapped inside and leaking up on the stroke
causing smoke and a sort of loud detenation noise under
higher RPM's and under load. JUST A THOUGHT

 

[addo]

It's honestly unlikely. But I wouldn't say not possible.