Rebuilt engine smokin' up a storm

Raindem

Veteran Member
Jun 3, 2012
173
Sonoita, AZ
I didn't have a lot of time to work on it today, but I did conduct the intake test and it passed. No vacuum at the dip stick tube (although it emitted an oily mist if that is important).

I'll start replacing the valve seals tomorrow. If that don't fix it, is there ANYTHING else it could be, besides rings, that I haven't already checked.

Thanks as always.

Curt
 

Raindem

Veteran Member
Jun 3, 2012
173
Sonoita, AZ
Well, I replaced all the valve stem seals and Damon was right. It did not solve my problem. Barely made a dent in the volume of smoke (although it does seem SLIGHTLY less. Maybe I'm imagining).

Here's a couple more clues I've noticed the past few days while working on it...

- It doesn't smoke when cold. After replacing the seals it idled for around 10 minutes before the smoke started coming out. As I understand it, this is opposite of what should happen with worn valve guides.

- Disconnecting the PCV, vac modulator, and oil breather has no effect on the smoke. I tried it both before and after replacing the seals.

- reving the engine or idling at high speed has no effect of the quantity of smoke (it just blows out faster with engine speed)

- there seems to be a lot of moisture coming out the tailpie when it's started up cold. Maybe that's normal, I don't know.

- I believe it's running rich. There's soot at the tailpipe and it has that rich smell when idling. Other than that, however, it starts, idles, and runs just fine.

I'm going to take it for a short highway cruise tomorrow (at night, because I'm embarrased to drive it in the daytime) and see if that makes any difference. What else can I try? Please, I need some more ideas.

Thanks
 

Damon

Veteran Member
Nov 16, 2000
12,939
Philly area
After you install the Crane limiter plate, you have to dial the intial back down to it's original setting. Then when it tops out, it does so where it used to (less what you take out of it with the limiter plate).
 

Raindem

Veteran Member
Jun 3, 2012
173
Sonoita, AZ
Damon said:
After you install the Crane limiter plate, you have to dial the intial back down to it's original setting. Then when it tops out, it does so where it used to (less what you take out of it with the limiter plate).

Huh?
 

cmonson

Veteran Member
Apr 7, 2006
4,134
Calgary, Alberta
I would remove the heads and verify your guides aren't toast.

Also, your compression is pretty low. Can you perform a wet compression test or leak down test?
 

Raindem

Veteran Member
Jun 3, 2012
173
Sonoita, AZ
Leakdown test already performed. 7%-14% across all cylinders. Compression was 120-145. I didn't do it wet because I thought those numbers were OK. I'll redo the compression test tomorrow.
 
Last edited:

Dogwater

Veteran Member
Dec 23, 2010
926
SanAntonio Tx
Your compression is low. One thing that might help to figger out what's going on is to do a compression test when the engine is at temp. (190°) You said it doesn't smoke when its cold, starts smoking when it warmed up. If your compression numbers are worse at temp. then it would seem as you have a piston ring problem. I didn't read everything but your sure its smoke an not steam? Looks like this engine is coming out for a tear down.
For a comparison when I first got my Camaro it had well over 100,000 miles on it, but guy I got it from took care of it. I did a compression test on it cold an the lowest psi I saw was 143 on one cylinder, all the rest were 148 to 155.
 
Last edited:

Damon

Veteran Member
Nov 16, 2000
12,939
Philly area
Let me give this another shot at explaining how to time the engine with the Crane limiter plate.

Starting point before install (typical example):

16* initial
20* centrifugal adv
20* vacuum adv
= 56* maximum total (way too much)

Install the limiter plate and the first thing that happens is it limits the vacuum advance but adds that amount to the initial setting (you're basically just partially advancing the vacuum advance canister). Looks like this:

26* initial
20* centrifugal adv
10* vacuum adv (half what it was before)
= 56* maximum total (STILL! AGAIN!)

So you need to pull the intial advance back down to where it was originally (16*) by retarding the whole distributor CW from where it was before. So it ends up like this:

16* initial
20* centrifugal adv
10* vacuum adv
= 46* maximum total (sanity, finally)

Make sense?
 

Raindem

Veteran Member
Jun 3, 2012
173
Sonoita, AZ
Work on the car is going to be touch 'n' go this week due to some house issues that have come up. But I'm going to be doing a wet compression test and also looking for signs that fuel might be getting into (and diluting) the oil. And even though the intake gasket test showed no problems I might as well remove the intake and visually inspect it. Also going to change the oil and plugs, lean out the carb, and check the timing. Getting back to the basics. It's possible more than one cause could be at work here. Maybe there's some gray smoke mixed in with the blue.
 




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