Oil drip from road draft tube

[Allmyjunk]

I have a 48 plymouth club coupe with a 53 p24 engne in it has been rebuilt in 1986 and not ran much sence then.  My car makes its mark ware ever i park it, the oil is comeing from the road draft tube.  Like enough that it is keeping the underside atleast on the passenger side from rusting any more.  Is there soposed to be a filter in the top of the tube to let it brethe and not puke oil, or do i have severe blow by.  I have been driveing the car quite a bit lately and smelling oil on the muffler is getting kinda old.  Any suggestion would be great.

[JBNeal]

partial PCV conversion

[dpollo]

If the drain hole for the back camshaft bearing gets plugged,  oil can rise up and make its exit through the draft tube.  However, this situation usually results in severe  loss of oil.   

[JOHN EDGE]

there is a removable /cleanable filter in the tube as it comes out the block. simple remove the tube(one long bolt) and you'll see the mesh filter.

I removed the tube and used the part coming out of the block and attached a rubber hose and routed the hose to a puck tank up on the firewall

with the breather cap- no more drips from the tube and still has a vent system or you could  route the hose thru a pcv valve to the intake- that's been done alot

[Don Coatney]

2 hours ago, JOHN EDGE said:

there is a removable /cleanable filter in the tube as it comes out the block. simple remove the tube(one long bolt) and you'll see the mesh filter.

I removed the tube and used the part coming out of the block and attached a rubber hose and routed the hose to a puck tank up on the firewall

with the breather cap- no more drips from the tube and still has a vent system or you could  route the hose thru a pcv valve to the intake- that's been done alot

Not a good idea. The bottom of the draft tube is cut at an angle designed to create negative pressure when the vehicle is in motion. There by sucking the crankcase fumes out of the crankcase and the oil fill cap is vented allowing fresh air to replace what is sucked out.

Much better idea to install a PCV system. I believe Vintage Power wagons sells such a system.

[JOHN EDGE]

true about the vent tube but many engines didn't use dip tube for venting the pan before pcv systems

came about.  many only used the oil filler cap for venting.  my 218 is bored .040 with edgy head and dual carbs and dual exhaust manifolds

and  I run hard on the interstate 70/80 mph on long trips without any noticeable problem. the motor is nice and dry with little or no oil consumption

I didn't like the underneath of the vehicle getting oil on it or the annoying drip when parked.  vintage power does sell the kit for a pcv valve but its a little ugly.

thought the dip tube looked ugly too

[Allmyjunk]

I dont really care how ulgy it is.  That answers my question this thing is soposed to have a filter in the top of the tube.  I didnt figure the engeneers made an oil drip on pourpse.  I will see what i can come up with and report back, thanks alot for the replys

[JOHN EDGE]

If you'll read my reply before this one I said there's a washable screen when you remove the long bolt and pull the cap off and yes the engine was design to allow  excessive oil to exit down tube. That's why it's called a vent tube

allmyjunk pull off the vent tube and see for yourself

[Allmyjunk]

I put the road draft tube in the car, it didnt have one when i bought it, the one i put in doesnt have a screen in it.  Just the long bolt and a almost 90 down to the ground and after you shut the engne off and im guessing while your going down the road oil is dripping out of it.

[Young Ed]

1 hour ago, JOHN EDGE said:

If you'll read my reply before this one I said there's a washable screen when you remove the long bolt and pull the cap off and yes the engine was design to allow  excessive oil to exit down tube. That's why it's called a vent tube

allmyjunk pull off the vent tube and see for yourself

I believe his 48 should have come with it new but not all flatheads have the style with the screen and filter. Some are just an L shaped tube. 

[JOHN EDGE]

You can make a simple material screen to insert in the round piece at the top

lots of old 2 cycle motorcycles used a brass mesh material in the simple air cleaner

for their carb. My 1959 Harley hummer uses it and that material is available. If your loosing that much oil I'd do a cylinder leak down test on all the cylinders and see the percentage of leak down. It's a great measure of how much compression is bypassing the rings. Might be the culprit 

[Allmyjunk]

Its not looseing a lot of oil just on the ground a tea spoon looks like a lot of oil.  Just more annoying than anything

[Flatie46]

If the engine hasn't been run much since the rebuild the rings may not be fully seated yet.

[BigDaddyO]

3 hours ago, Allmyjunk said:

Its not looseing a lot of oil just on the ground a tea spoon looks like a lot of oil.  Just more annoying than anything

It's just marking it's territory.

I used a 'Chore Boy' copper mesh as a muffler packing on my old BSA when I was a kid.

That might be a cheap, readily available alternative for a screen.

(It lasted long enough for me to take my road test at the DMV.

I blew it out on the ride home.)