I just installed a nearly new 383 into my car and it is now pumping oil out the dipstick tube. I know it could be the PCV valve, a broken or stuck ring, but what i dont really know is how to unstick a ring without pulling the engine. If its a stuck ring will it scratch up my cylinder walls if i run it? Any ideas would be appreciated.

 

I guess I should have said that was in a truck for a very short time and used as a mud truck and it never had a problem then, but it sat for a short time(maybe 3 months before i Put it into my car.

 

Do a compression check on the cylinders.

 

1st thing before you tear into the motor. Pull a valve cover off and see if you get a lot of oil coming out the pushrods. If it is splashing out. If it was a mud truck as in high rpm e.t.c it could have a HV pump with an upgraded spring. Check the oil pump spring. For HV it might either be red or white I cant remember off the top of my head. Whats the oil pressure at when the oil is coming out?

 

????? What does oil pump and oil/no oil at the pushrods have to do with oil coming out the dipstick tube? Cause it sounds like there is too much pressure building in the crankcase.

 

Sounds like a heck of a lot of blow bye coming from somewhere.

 

I would perform a leakdown test on each cylinder and see if the rings are any good. If the rings are bad then they will allow combustion pressure to leak down into the crankcase and its easiest way out is the dipstick tube. Did this engine ever suffer from no spark while cranking and someone just just cranking and cranking and cranking? that alone will fuel wash the cylinders and glaze over the rings. If thats the case then guess whats next..... rebuild.

 

Ah yes the rebuild.

 

Lets see, if there is no oil coming out of the pushrods wouldn't that mean there is some kind of restriction preventing oil from reaching the lifter valley and finding the easiest route to flow, i.e the dipstick tube? :/ Or the pump is no good and the oil is sloshing around in the pan causing it to pour out the tube as well?

 

Yes mean restriction or bad oil pump, easiest route to flow no, the oil pump doesnt pressurize the oil pan. Oil sloshes anyways even with a good pump.

 

Crankcase pressurization is not uncommon on big cube motors especially it you hit some big revs , there is little vac at revs to pull gases through the PCV valve so they blow out wherever

 

Ok, I will do a compression test although It seems very unlikely that that is the case since it has always(even the first start up) started quickly.

 

Just trying to get him to look at the easy stuff 1st. Most of the time with our wonderful engines if you overlook the small stuff; after you spent a ton of time chasing your gremlin and then noticing the small stuff; you want to kick a puppy, been there, done that

here is another great trick to see if it is blowby, TAKE THE OIL FILL CAP OFF. if the oil still pours out it is not pressure. If it does there is your starting point. Replace the pcv valve, if only 1 valve cover has a pcv hole get another cover that has 1 and then check again. Taking a valve cover off to check oil pressure would also make a nice escape route for the pressure.

 

The thing that does concerns me is to relief the pressure by say improving a breather system which by doing so masks the root cause. Now a leakdown test is not a be all to end all. It is a tool to be interpreted by the user. And it "helps" you decide if you need to teardown a engine or not. But I do think it is a test you should run so your not merely masking a root cause with what you do.

 

Let's not confuse a compression test and leak down test.
They are two seperated testing procedures.

 

Nope.Not confused at all. Leakdown will also show blow-by more distinctly. We leakdown our race engines wkly for yrs.

 

i knew someone that this happened to, after every trick tried,beers and head scratching come to find out he installed the rings upside down!

 

Well, this is just running my way to much money...I just found out that I have the wrong headers on it and my custom exhaust builder cant put an exhaust on it. Anyone want a 87 Iroc-z28 (g92 car) originally a 305 tpi that now has a 383 stroker built from a early 70's block and the early 70's LT1 heads with 1.5 rollers, a .288 .550 cam that is doing the above problem? It sounds awesome, but I spent to much money for the car originally and then the engine started banging and clanging within a week after purchase so I thought, no time like the present to put a 383 stroker engine in that bad boy....not realizing how much more than an Engine this would take.

 

Sorry to hear the woes
Turning over quick has nothing to do with cyl pressure.
Oil passages do not become "clogged"
Rings wont stick in 3 mos either

Gut feeling says your buddy sold you a tired motor
(theres a reason he sold it)

Best of luck.

 

I'm not going to tell you made a mistake buying the 383. Why??. Because I don't know based on what you have posted so far. Take a deep breath,regain you composure,then go back and run the tests we all have suggested. Posted that next. We can go on from there.

 

make sure that pcv valve work correctly and on the other side make sure the filter on the valve cover is not block from oil debris or mudd...if the filter is block the pcv will not work at all

 

Ok, after finding out that a compression test and a leak down test are 2 separate tests, I have been unsuccessful in finding someone with a "tester". However, I did see that under the car was a little oily, so I asked the guy(mechanic) ,who put the oil in and started the car and said oil was coming out of the dipstick, what it was. He said it was the oil tha had leaked out of the dip stick tube...and said that he would guess a full quart had leaked out before he pulled the PCV valve. After he said he hadnt added any more oil, I checked the oil and it is perfectly on the full line and the car was level.

Could it have been a quart high on oil and pushed the oil back out the dipstick?

 

Very possible

 

possible yes but highly unlikely. Oil coming out dipstick tube means you have blowbyor youre upside down and should roll back over quickly. Besides a 1/4 cup of oil that is slowly pushed out can make a BIG mess.

 

I would agree that this is a case of excessive crankcase pressure which is caused by blowby. Remove the PCV valve and makeup air tubes from the valve covers and see how much blowby gas comes out of the openings. At idle there should be a very small amount. As you snap the throttle, the amount will increase but it should still be a fairly light rush of air.

Even a healthy race motor will often not work with the factory PCV system. The higher compression causes more blowby resulting in higher crankcase pressure. Many racers run a crankcase evacuation system including a high flow vacuum pump like what I have on my 355. These are generally used with low tension rings to reduce drag and increase top end power. At the very least, you will probably not be able to use the stock PCV system. Try installing valve cover breathers instead. If you get alot of vapor coming from the breathers and/or if you get oil coming from them, you may be stuck re-ringing the motor or installing an evacuation system. The results of a compression test will tell you which one you need. If the vapors come in a big puff one time per cycle of the engine, it could mean a broken ring on one piston. Again, a compression test will tell you which hole is bad.