I picked up a 81 firebird in ok shape on friday. Had a few minor problems. One was the oil pan leaking. Droped the oil plug and had about 13 quarts of what smelled like gas and oil shoot out everywhere. So I got the oil pan off by the way this is a chevy 350 motor, and found a peice of the passenger front piston in the oil pan. It is the small peice that sticks down below the rings. There are two of them and one is broken off. Can I still run the motor like this if i put it back togather or do I need to re-build. Also does this have anything to do with the gas in the oil. Any help today would be great .

 

Dam no one knows?? Cant get the oil filter off any way and now its leaking gas/oil and called it a day. Gues I ll have to pull the motor to get the filter off any way.

 

there's various degrees of what you can get away with, but depending on the size of the piston piece, ( is it part of the skirt? ) that is in the pan, that cylinder is going to be out of balance, and the higher the rpm you run the more force you're going to place against the crank and main bearings. That in combination with a ton of gas diluting the oil so there's no lubrication will kill the motor.
being that it's an '81, I'm guessing it's carb'd, with a mechanical fuel pump. If you truly had 13 qts of oil/gas (mostly gas) then I would first look at the fuel pump on the block. To have that much gas in the oil i find it hard to believe it all got past the rings unburnt on you're busted cylinder, but who knows.

 

Yea it is just the little ear of the piston that broke. there was a mechanical fuel pump but it was removed and there is an electric one now.

 

Moved from Advanced Tech section.

 

Did you say you got 13 qt out of the block?????? I would be seriously concerned if I were you. No way that was fuel leaking past a ring, and I really don't see how you would have a running engine that full. Are you sure it is fuel in the oil and not just really bad coolant? That is the more likely contaminant (fighting that on a 3.4L right now!). I personally would not run the engine knowing a piece of the skirt was in the pan. I would be very concerned about the condition of this engine. You really should pull it for a rebuild or replacement. On the upside, small blocks are pretty easy to find if there is a serious issue. You can also look around for an inexpensive used short or long block to replace it with. You find decent running SBC in the $150 to $500 range all the time. Might be the fastest way there from here. As for the oil filter, a common trick is to drive a screwdriver through the side of it to give yousomething to twist. I would try a strap wrench first though. As for just putting the pan back on and pretending ther eis no damage, I really have to reccomend against it. You had almost 3X the volume of liquid in the crankcase, that is not a minor issue. Also, fuel and coolant both tear up your bearings, so expect a short life out of them at this point. I really don't see a good way to get 8qt of fuel into the crankcase.

 

was there a mech pump on it when you bought it? or before you started any work? have seen many mech pumps go bad and just pour gas in to motor.

 

You can rebuild it if the block is ok, just buy new pistons STD if it will hone out if the cylenders are not scarred, turn the crank and slam it back together.

 

He said there was an external pump on it, so I really don't see how the fuel could get in there. That is 2 gallons of gas! It would have taken a while to dump that through the carb, into the cylinders and past the rings. The PCV should have vapored a bunch out as well.

 

With that much gas / oil in the pan, Id replace it all.
Had a similar thing happen to me. Ended up spinning a bearing.

 

Is that external fuel pump set up for around 6PSI (Carb pressure) or 40-60PSI (Fuel Injection pressure). If you are using a really high pressure on the carb, the inlet would always be open, and it would pour gas into the intake. This would get the gas in there, but the car would never have run in that condition. Just another thought on how that fuel got in there. There has to be a way for it to have gotten there. Maybe the guy you bought it from put the external pump on because of a mechanical pump failure and the gas has been in the oil? Hard to believe it would run with that much fluid, but if it has been in there, your bearings are going to die. This one really has me puzzled, the only place you have fuel near the engine is at the carb...

 

Well found out the intake gasket was leaking. Got that fixed and changed the oil a few times. The car runs idles ok. When you give it alot of gas it kind of falls on its face. Is this due to the piston skirt missing or do I have other problems. Timing is ok and I have new spark plug wires. May think about doing a 383 stroker

 

just make sure the timing is ok, If its to far out and running you can wash a motor out over a long period of time, which may had been an issue with your xtra fuely oil, keep an eye on the oil level, rings may be wshed or fuel pump leaking internaly.. i wiped an eagle 383 kit out due to leaking fuel pump. silent killer!!

 

Well the car is falling on its face because the choke was closed! Now I am having idle problems.