8BA Flathead oil leak/pressure issue

I have an oil leak/pressure issue with my 8BA. It’s all stock with the original style mech fuel pump and all. After a 10-15 mile drive, the oil pressure drops off and oil seeps out through the fuel pump stand. I put all new intake gaskets on recently, but the problem still exists which makes it very apparent I have a much larger problem. When I had the intake off, I had a considerable amount of sludge in the valley, so I’m wondering if there are galley holes that might be plugged up with sludge causing oil to become trapped in the top end, or if it might be an issue with the fuel pump pushrod not being seated properly. I did my best to search on the topic before I asked, but I didn’t see anything definitive. Any ideas? Thank you in advance.

 

You used an 8BA gasket and not an earlier one, right? Really, I don't know if this is feasible, but if you used an earlier intake gasket by mistake, could you cover over the breather and now pressure is building in the engine and pushing the oil out of the fuel pump stand? Just a WAG.

 

No the gasket was correct. It only fits on one way, and I had the issue prior to the gasket change.

 

It sounds like an internal air pressure thing. Just not breathing correctly.
Do you have the draft tube on?

 

Draft tube is still there, and as near as I can tell, not clogged.

 

It's not the draft tube that gets clogged, it's the mesh in the oil fill cap. And yes there are drain holes in the valley that could be clogged. There is also a gasket under the fuel pump stand.

 

MONSTER...damn brother did you just leave all that sludge in there. O.K. i will chillout for the moment. well the moment has passed, and now my pants are sludged up...POP.

 

I ran it without the breather cap on with similar but not as dramatic results....and I replaced the gasket under the stand as well as where it mates up to the fuel pump and applied a liberal amount of sealant.

 

I was afraid to jostle it all and make it worse!

 

Does you intake have a tube in the front that runs down into the crankcase; (NOT THE ROADRAFT TUBE) about 1-1/8" OD? Sounds like a crankcase breathing problem to me. You might want to consider a PCV valve install; pretty easy on a flatty if you hide it under the intake manifold.

Jim

 

Blown 49 sounds right on the breathing issues. As far as oil pressure dropping, what is the engine history, semi fresh or old n tired. The sludge sounds old. If it is many moons since its last rebuild that will explain the oil pressure drop. When cold the oil will give better pressure as its thicker as soon as it warms its thinning down some. 15lb at idle is lowish and 30lb at freeway is probably a low as i would like to see it. 30 at idle and 60 at freeway is somewhere near a fresh flatty.

 

The motor is old and tired for sure, and I understand that pressure drops as the engine temperature increases. When my engine is at temp and the pressure drops down, I can pull to the side, wait about two to five minutes and then start it again and have more than ample oil pressure, which has led me to believe that the oil is getting trapped in the top end, and trickling back down slowly. I guess the question I should be asking is where exactly the oil is supposed to bleed down through so that I can find that area and free it up.

Blown49: Are you talking about the tube that the breather cap sits on? Yes it's there. It's all stock except for headers.

 

Also check your screen in the oil pump..if you have that much sludge in valley,pan bottom is likely to be likewise...when you stop the engine,oil will bleed thru the stopped up screen and give good pressure for a short run on restart

 

Possibly losing pressure at the pushrod bushing. Check to make sure you have a 7/16" dia. rod. Have seen a couple with the wrong dia. pushrod.
Sketch shows pressurized lube hole in bushing

 

I have soaked the screens forever in cleaner & they never opened up they seem to be varnished. Probably a stronger solvent, acetone would melt it.
Also there are 2 tin covers over the return holes in the valley, clip on to the tube in the center of the valley, blocked with gluck there. The relief valve is on the pump, if pulling the pan to clean the screen could shim the relief spring to jack it up a bit...

http://www.vanpeltsales.com/FH_web/FH_images/FH_engine-pics/Flathead_Engine_oilpump1949to53.jpg

 

There are drain back passages at the front and rear of the engine and in the middle.

 

Here's a pic of the breathing on an 8BA/9CM. If you have that much sludge in the lifter area I believe I'd be concerned in how much may be built internally in the crankshaft. Loss of oil there and you'll be looking at rod bearing replacement for sure.

Any yes the tube under the breather is the one I mentioned in an earlier post.

Probably a tear down is in order though I don't think you want to hear that.

Jim

 

Pull and read the dipstick when you loose oil pressure. May be it will eliminate one possible issue.

 

In case anyone is keeping score...I think I fixed it! I pulled the fuel pump pushrod out and it had an umbrella on it which I know isn't stock for an 8BA. It was however, the same length and same diameter as the new one I just bought. The old one was hollow and had two weep holes at the bottom and one at the top. I think it was filling up with oil as I was driving and spewing out the top after it got full. Must have been something someone pulled out of a parts bin.