My motor has always smoked at WOT since I put it in.

I initially thought that the PCV was sucking oil and it was being burned, but now I just switched to a dual breather setup on each valve cover.

Now you can sit there and watch the breathers smoke when the car is running. How much (if any) smoke would you expect to see on a crank case where no vacuum is applied?

Also, last time I had my motor torn down I noticed the cylinder walls are scuffed, I assume from the piston skirts. I think it was Cyl 6 and 8 on the outward (exhaust port side) of the cylinder had verticle lines up and down through the cross hatch. Those cylinders compression checked and leakdowned the same as all the others, but now I wonder if that could be contributing to the smoking breathers.

Ideas/suggestions?

 

If you didn't correct the scuffing when you put the motor back together, you would pick up extra oil from the walls.

 

Hot oil WILL smoke.
If the motor was put together without the proper ring orientation that would explain the vertical scratches.
Were they all the way to the bottom and a little over half way up,or did they come all the way to the top?
Did they go all the way to the bottom?
Were they not honed out for the new rings?

 

I should rephrase, the motor wasnt completely torn down, I had the heads off and shortblock still in the car. The rings are original to machine work on the engine done by Tony Bischoff. Only has a few thousand miles on it and has never been taken apart.

The scuffs were at the top portion of the bore and went about half way down the wall. It was scuffed enough that you could feel a slight change in the surface with your finger. Wish I took a picture of it now.

Lets make the assumption that oil is holding in the scuffs. It would make sense then that that oil would smoke in the crankcase and cause the breather smoke.

Would this be enough oil to cause detonation, other concerns or can I just live with it for the time being? Ill put a draft tube on the car and call it a day, lol.

 

What is the oil pressure on the car? I had a very warmed over 327 that did that, and it was pretty bad, until I went with a larger pan, and an oil cooler, also I was running near 60 PSI of oil pressure.....

As for the scuffing, it would depend on the severity, and if it is VERY bad... it could cause issues with detonation..... a serious issue if you are spraying....

 

About 50 psi up top. High volume pump, 7 qt pan + 1 qt filter.

 

Yeah, every time I have run lots of Oil pressure it is just something I had to deal with unless it had the oil cooler on it.......

If it was smoking out of the exhaust I would be more concerned about the scuffing, but if you are not showing exhaust smoke, and just breather smoke, then the amount of oil that is in the combustion chamber... if any is likley to be very low.....
If it is not running an adder, it will be just fine.......

Crank case evac system would be worth while to clear the smoke, as would a cooler.....
also the evac system will help stabilize the rings....

 

The hot oil in the pan WILL smoke. Take a quart of oil,put a temp gage in it and put it on the stove to see what temp it smokes at. It was pretty common to see pre PCV cars smoke out the draft tube especially on high humidity days.
Tony does good work,but things can be overlooked if ya are in a hurry. Tony probably didn't build your engine but he has or did have some pretty sharp cookies working for him when I lived in Cinci.
Sounds to me like the rings never seated and if they are orientated like the factory says that could be your scratches from the ring end's laying on the down side. That's why I never do them like that. Seen too many factory engines with the duel scratches and sometimes 4 all the way up. Hey that's the way I do them,that's not the recognized way to do it according to the book. I have not had any scratched up cyl walls either and most of my engines don't need a rebore the next time it is taken down for an upgrade due to gouges up the cyl.
Just leave your breathers like ya got them unless it's causing a mess and make sure your PCV is working correct.

Exhaust evacts are not recommended for the street. It takes a lot of your splash oiling that goes on and prevents it from happening by pulling the oil to the bottom of the engine or the sides of the block. Read about them and see what the manufacturer says. I have run them but not on a daily driver. Where it will hurt ya the most is the cam and roller's.

 

Agreed..... I have seen them for limited street use with good results, but not daily drive useage.....