I recently purchased a 1997 camaro z28 with a built 383 stroker with a vortech V-1 supercharger running at about 7 psi. And when i run it hard at high rpm it smokes a little bit, then when i let off it smokes a lot. It smells like oil, and quits smoking when the rpms drop back down. If i just floor it at lowish rpm, no smoke or oil smell.
The motor doesnt have enough miles for the piston rings to be worn because the whole car has 85k miles, and the motor has less than 20k. and the weird part is the oil doesn't go down much, so its not burning quarts at a time or anything.
I do know it runs really rich, so i think the o2 sensors are bad, but i am changing them tomorrow. But o2's wouldnt make it burn oil.

Does anyone know what this could be?
I was thinking the supercharger might be blowing some oil into the intake, but i pulled it off and there isn't oil residue or anything.
Any suggestions would be awesome!

 

You have a stroker with a supercharger. The longer stroke increases piston speed which can lead to ring flutter which allows more oil through the rings. The supercharger increases combustion pressure and blowby. As RPM increases the problem gets worse, which can lead to oil burning at higher RPM. Personally I would just live with it, and it should cause no real problem unless you are running a road race. It does not take much oil burning to create smoke. Is there additional crankcase venting or is the PCV the only thing removing crankcase pressure?

 

what oil are you using?

 

I'm not sure, a shop did a complete tune up, all new lines, fluids, and plugs and everything, so I'm not sure what oil they put in it.

And @ z28pete
It only has the stock PCV valve. But the other day, i was taking my friends for a ride, and after a few hard runs it blew the pcv valve out of the valve cover.

 

Sounds like you have ring blow-by issues, they may not have seated properly.

 

Do you happen to know if the engine was built as a supercharged engine, or was the supercharger added later? Blown engines punish piston rings, especially the top rings. Stock type rings do not fare too well in this environment and excessive blowby is a problem. As Chuck indicated, blowing out a PCV valve is not a good thing and shows that excessive pressure is building up in the crank case. This pressure can force oil where it is not supposed to go. You can probably live with things the way they are if you limit the amount of time you keep the pedal to the floor. You may also consider adding breathers on the valve covers to let the pressure out.

 

With what's going on, you might want to consider installing a crankcase evacuation system, something more positive to pull crankcase pressure out. With the pressure you're building up, the small amount of blue smoke and popping the PCV valve out could be the least of your problems. You can eventually pop an oil seal, giving you nice leaks, plus excessive crankcase pressure can hurt your ring to cylinder wall sealing capabilities. Kits like: this one, has the exhaust drawing the pressure and fumes out. Yeah it's more work than slapping in a valve cover breather or two, but your engine is telling you it isn't happy with having only passive venting.

 

I is low compression, built for forced induction.
Im about to have the complete build sheet on what internals, and what stroker kit it has, and when exactly it was done.

And a little off topic, but can o2 simulators go bad?

 

I agree with everything that is said above but just wanted to add, Normally when the smoke get worse on throttle let off I look at the valve seals and verify that the oil is returning to the oil pan fast enough. With high volume oil pumps and high RPMs the head area can pool up with oil if it can on drain fast enough. Also many old school race engine builder will not use good valve seals and tend to just use a O-ring because they do not care about a little smoke. Combine that with a lose fitting intake valve and you got a smoger when you let off the throttle. Remember vacuum is at it highest on deceleration. Pooling oil combind with little or no valve seal will suck oil into the cylinder faster than a 2 dollar,,,, no wait family website, you get my point.

 

The O2 syms are only used after the cat to monitor its condition. I suppose they can go bad, but they would not affect how the engine runs. They definetely won't work if they are used in place of the upstream O2s that control the fuel mixture.