Valve Cover Flooding with Oil

[parkerdevore]

B8200. I believe it is a 950 engine.
I rebuilt it last year, lower end. This week replaced cracked head.

I have owned the tractor two years.

The problem: After 20 or 30 minutes of run time the value cover fills with oil and pushes the oil out the vent pipe. Happens anytime the engine is ran over 1400 rpms. Has light blow by from vent pipe.

I have ask everyone I know. No clues.

Can someone offer a suggestion.

 

[moog]

I may not even know what I'm talking about ... but your drain/oil return holes aren't blocked somehow are they? You got the head gasket on correctly?? You made sure everything matched up before bolting the head down? Did you have the head repaired or did you source one? If you sourced it out did you check to make sure all the holes etc etc lined up? You didn't leave anything in the drain holes? Sometimes I cover things up to keep dust out and I've forgot a time or two and had to take a thing or two apart.

I know you probably did but just askin'...

 

[parkerdevore]

Thanks for the response. I cannot remember this happening before I rebuilt the lower end maybe it did. Just cannot remember.
I rebuilt the tractor a year ago and when this issue arose I wonder a couple of things: 1. Something blocking the drain holes on the head. 2. Could I have missed the oil metering plug and had it been left out when the block was sleeved.
When I took the head off this time, I check the head gasket for alignment of holes and the metering plug was in place.
Seems dumb but it seems to really pump oil, in volume, from the valve cover hose when I am turning right.
Does the oil flow back from the head into the chamber on the front of the engine that houses the timing gears. I had been told that that gasket might be blocking return holes. Just a guess.
I appreciate your responses. I need to get this fixed. My grass is bale-able.

 

[Stumpy]

So you've removed the fill cap when it's doing this and the valve cover is full of oil?

On my engine (which is similar) oil flows down the push rod cavities into the lifters, out of holes in the lifters into the camshaft tunnel. As I recall there are two drains down through the block from the tunnel to the sump. It can't come out the front by the cam gears, the front cam journal and retaining plate block it.

You could be generating pressure in the crankcase and as it escapes up to the valve cover and out the breather it's preventing the oil from flowing down to the sump. Could be the oil is overfull and when the pistons are moving down you get a pressure pulse. May also be excessive blow by from the rings but I have my doubts about that.

I was going to suggest the oil nozzle but you've got that covered. Might be a good idea to check you oil pressure regardless. If it's leaking past it somehow that might explain the excess flow into the head and it would probably show up as low oil pressure.

I'd think you'd have noticed plugged lifters. Were there any signs of sludge in the engine when you had it apart?