Newly Rebuilt 5.0 - Continuous smoke out of one pipe! Help!?!

[oz]

Greetings,
I need the help of the 5.0 crowd with my old 5.0 (302).

I finally fired up the old 302 today for the first time after the rebuild. Everything went as expected except for one thing - after 15 minutes of cam break in, there was still smoke coming out of the left side exhaust pipe... a lot of it.
The right side exhaust was clean.

The smoke was whitish gray and hung heavy in the air. It did not seem to disipate like water vapor would. It did not really smell like oil either.

What could this be?

Here's what I did to the engine:
'69 302 bored +.030, speed pro pistons, moly rings, edelbrock 7122 cam, performer RPM intake, 600 cfm carb, hand ported stock 302 heads, new valve guides, hardened seats, screw in studs, full roller rockers, etc.

I bought used long tube headers from a friend, sand blasted them and coated them with Eastwood header coating. When I started the engine the headers gave off an ungodly amount of smoke for about 5 minutes.... It eventually stopped but the smoke out of the left pipe continued. I doubt if there is any connection here....

I am running a PCV out of both valve covers during break in (as recommended by a friend) - one to the carb base and one to the intake just below the carb. Could this have something to do with it? Yea, grasping at straws - don't want to tear this thing apart again....

I assume i either have a water passage leak, a blown head gasket (there were several backfires trying to start it initially), a piston ring problem, etc....

Any suggestions would be appreciated.

THANKS!!!!!!!!!!!!!!!!!!!!!!

 

[dderek]

ouch. if the smoke kinda smells sweet.. then thats coolant being burnt. and you probably have a bad head gasket on the left side. or it slipped when reinstalling.
or maybe some of the valves are very badly out of adjustment to that cam. i really dont know much about valves/cams.

but its a good idea to figure out what youre burning. then that will help diagnose the problem.
um, as far as i know
blueish/white = oil
white&sweet smell = coolant

hope that helps a little at least

 

[88stangmangt]

you might have a blown head gasket like stated above pull the compression numbers and see what the deal is your seals on your heads might be leaking oil into the cylinder.since they are stock the seals could very well be shot............

 

[5.0Droptop]

could be the intake manifold gaket moved on it when you set the manifold on. Could be sucking coolant in through there.

 

[oz]

Thanks for the replies.

It was strange but the smoke was pretty dense. It did not disipate into the air like steam (coolant) usually does. It was white and it stained the grass on the ground behind the car.

I will do some more diagnostic work on it tonight. I hope I didn't get too close to a water passage when I ported the heads.

The heads are stock castings but were completely rebuilt (including guides and seals).

One thing I did notice later was that there is a little oil in the bottom of the intake. It is a dual plane Edelbrock (...carbed setup). The one PCV hose actually runs down hill to the base of the carb from the rear of the right valve cover. When I took the hose off, it had some residual oil in it. I had to remove the baffles from the valve covers (I'm using the cool ribbed aluminum ones from an '83 GT) so I wonder if oil is getting sucked in as a liquid directly from rocker splash? I will plug this hose and try it again. I still don't know why only one bank would smoke since the dual plane intake feeds 2 cylinders on each cylinder bank from each side.... unless the oil from the PCV is running down the #8 runner and into that cylinder... hmmmm?

 

[Iowa91LX]

Have you changed the oil?
Try that if you have not. A lot of cam lube/engine assembly lube in the cylinders will make the exhaust smell and smoke.

Once you get your new oil in there then start to worry if its still smoking.

 

[dude5l]

If the smoke was blue, it would be oil, black= fuel, white/grey=coolant. It sounds like a head gasket or intake gasket.

 

[2muchtime]

Thanks for the replies.

It was white and it stained the grass on the ground behind the car.

One thing I did notice later was that there is a little oil in the bottom of the intake. It is a dual plane Edelbrock (...carbed setup). The one PCV hose actually runs down hill to the base of the carb from the rear of the right valve cover. When I took the hose off, it had some residual oil in it. I had to remove the baffles from the valve covers (I'm using the cool ribbed aluminum ones from an '83 GT) so I wonder if oil is getting sucked in as a liquid directly from rocker splash? I will plug this hose and try it again. I still don't know why only one bank would smoke since the dual plane intake feeds 2 cylinders on each cylinder bank from each side.... unless the oil from the PCV is running down the #8 runner and into that cylinder... hmmmm?

that is definately one problem. you can pretty much guarantee its sucking up some oil..

any engine ticks??
change oil??
is it responsive when givin it a little gas from a sitting idle??
what color was this stain on the grass??

 

[oz]

It was the second PCV I installed on the right valve cover.... I installed the PCV directly into a gromet in the valve cover. The PCV was not shielded from oil splash.
Spark plug in #7 was soaked with oil. The port the PCV was hooked to on the intake aperantly dumped all the oil down the #7 runner.

I cleaned the plug and removed the second PCV and the smoke is gone.

Thank God it was something simple

THANKS!!!