Engine smoking...and I don't know why

Rocketdog1

Rocketdog1

Member
Hey all-

Need a little help on this one. '31 SW, stock engine. Did a few things to the engine today (exhaust manifold w/gasket, cap/rotor) and double checked the timing. She starts right up and seems to run pretty smooth (much quieter as well with the new manifold gasket!). The timing appears to be about 0 deg. at idle with the lever all of the way up - about 2/3 down and I'm 20+ degrees advanced - so I'm pretty sure I could get 30+ degrees if I wanted to. All verified by timing light.

The problem is that the darn thing has started smoking quite a bit. It's a blue-ish smoke, like she's running way too rich - or burning a little oil. GAV setting about 1/4 to 1/2 open with the engine warmed up. Doesn't seem to matter what I tweak or fiddle with, the smoke won't go away completely.

I don't remember it doing this the last time we went for a drive, so I'm puzzled.

I don't really want to tear things completely apart, but I guess I will if I have to. If you need further information, ask away.

Thanks in advance for any insight.
 
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White smoke is water steam

Bluish is oil burning

Black is too rich

Anything done or changed just before the smoke started?
 
First off let's see iF the GAV is working. When the engine is warm can you turn it in enough to make the engine run rough and then turn it out enough to make the engine run rough and then find a sweet spot somewhere in between? A GAV can be physically closed too tight where the tip gets a ridge or groove cut into it and it no longer will work properly and goes from being totally shut to letting too much gas past and results in a rich mixture.

Smoking may also be from a too high oil level in the sump. Oil level ok?
 
Well, it's not black - so we can rule that out

Not losing any water level, and it doesn't appear white (seen that before on a different car) - so I'm pretty sure we're not talking about coolant.

Which leaves burning oil - blue-ish in hue. And frankly smells like it as well.

And no, other that setting the timing and an entire new exhaust system, nothing has been done in recent history.

Rings? Valves? Genie looking for it's freedom?
 
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how about a compression test before we go any further

have you been running MMO in the gas as upper cyl lube? Could be a stuck ring
 
GAV fully closed and she roughs up a bit.

As I open up the GAV, she smooths out at about 1/4-1/2 turn, but I can keep opening it up w/o having any impact on how the engine is running. 5 turns open and she still purrs. Thought that was a little odd.
 
Don't have a compression tester, so that will take a little time to procure and perform.

However, I agree that it would be prudent.

And oil level is fine - not overfilled. Just triple checked it and level is just below the "F" on the stick.
 
I had that thought as well, but I have run the engine for some time and would have a hard time believing that this is still the "newness" burning off the exhaust system.

A little at first I could buy. But this goes beyond what I would consider burn-in.
 
Have not run any MMO as of yet. I've only had the rig for just under a month, and only filled the tank once during that time (non-ethanol btw).

Was seriously considering running some MMO or Seafoam - have had good results in the past with other rigs.
 
I just guessing you may have disturbed some carbon in the ports that has gone in to the cylinder
pull the spark plugs and do a leak down
 
Further info:

Aries exhaust is a couple weeks old - so it's well "burned in". Only did the manifold with gasket today, as it was discovered to be toast when the Aries was installed.
 
my guess is either a stuck or broken rings, wont be able to tell till you do a compression test, a compression tester can be your best friend when trying to find engine problems, buy or borrow one
 
Years ago, a good friend complained about his engine smoking, but it turned out that a previous owner had replaced the vacuum fitting in his intake manifold with a grease fitting and he had been pumping grease into it whenever he greased the chassis.
 
Check the crankcase/oil filler tube any kind of restriction will cause back pressure in the crankcase and oil burning.

A oil change refill is 4 qt's, 5 only after a totally dry rebuilt engine.

just my WAG at the problem.
JB
 
- No air filter

- Plugs look reasonable - nothing way out of the ordinary - and they all look essentially the same.

- No obvious restriction in the oil fill tube

- New manifold did have some (machining?) oil on it, but with as much as I ran the engine today, all of that film had to have burned off by now.

- And last but not least, I am absolutely certain that I'm not greasing the intake.
 
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