Crankcase pressure on a new rebuilt-pushes oil out dipstick.

[rwflyboy]

Hi, I am new here... got an issue that hasnt been resolved by my mechanic as of yet. We have a type 4 motor 2.0 Ltr, carb weber-progressive, hydraulic lifters, in our 76 Westy. Put a "new" rebuilt type 4 motor in last year, had an oil leak issue coming from the dipstick. We drove on the motor several thousand miles with no issue other than oil consumption/leaking. On a 2450 mile road trip to the Fla Keys we used a little more than 52oz of oil on the trip. (We measured the oil going in each time we added with a measured glass cup to verify the amount used. ) After trying many things, the engine company provided a replacement engine. Guess what? Same exact issue now exist after only 100 miles.

Breather issue?
2nd Bad Motor?

[The Newf]

Just curious where you're getting the motors from.

[rwflyboy]

Bus Depot/AVP.

[The Newf]

I don't have many suggestions except to check the crankcase ventilation system for correct function/obstruction assuming the oil level dipstick fits correctly.It would take a fair bit of crankcase pressure to push a correctly fitting dipstick up out of its tube.
Take the breather hose off. Rev the engine to about 3K rpm to see what kind of air flow you're getting from the crank case.Doesn't sound good from here.

[Piledriver]

How much oil are you putting in it on fills and does it have the OEM dipstick?
Does your engine have head breathers? (suggest capping 3/4 side if so)

The dipstick is supposed to have a little felt seal under the cap, One could also likely use a small oring if the original felt seal is gone.

If the dipstick simply flops around loose, you can carefully expand it where it goes in the tube, then bend the tip back in with a ~screwdriver holding the two sections apart while bending. (provide a ~1/32" or a bit more gap between the two halves)

A ~quart and a half in 2450 miles is quite good, particularly from a new engine while still seating the rings etc...

I take an old distributor cap wire boot, invert it, slip it on the tube so the dipstick fits inside the cup...and the OD of the dipstick seals.
OTOH I run some case vacuum under most conditions, so that sucks it down to seal well.

[heli-easy]

Getting blow by on your piston rings. Rings need to break in, or there is something not right with the rings.
I'd try breaking the rings in. Change oil with breakin oil. Mineral non detergent. Then drive it hard up some steep hills. Get it good and hot. The. Let it cool down. Then drive it normal see if it's better.

[rwflyboy]

Thanks guys.. I do appreciate your responses..will let you know what we fine here soon.

[Piledriver]

Serious Warning:

Most "mineral non-detergent" oil you find is SA grade, which means it is (technically) ~suitable for a Ford model A.
Note they once managed a few thousand miles between rebuilds...
It would last a LOT longer with modern oils.

SA grade non-detergent is super cheap base oil stock with absolutely ZERO additives.
It is made for desperately cheap people who don't know any better.

If you want to play with break-in oil, buy real break in oil, not oil literally not fit for even a lawnmower.

Break in oil will have loads of ZDDP and other anti-wear additives, and ~no detergent to allow them to build up the required anti-wear films quickly. It will have some antioxidants as well to keep the motor from rusting, allowing you to keep it in the engine for more than a weekend.

If you have glazed bored only a deglaze/rehone (and possibly a rering, may get by with just a quick deglaze) will bring it back.
Usually caused by way too much fuel/rich mixtures during initial breakin.

You have flat tappet lifters. You need an oil made for engines with flat tappet lifters.
Most randomly selected oils grabbed off the shelf are NOT suitable for engines made before 2007.
This includes Castrol GTX. Forget it exists, it isn't the same oil it once was...

There are good and cheap and suitable for flat tappet lifter oils available ~anywhere if you do some research.

Please read at least a few of the many long threads on the subject.