I am runing good, breather and PCV valve in my stock 350 and it takes 150 miles for the OIL (high quality) to get completly dark.
In more modern cars I have seen it takes much more for the oil to get dark.
The engine got about 20K on it and almost healthy.

What about yours? Any trick to prolong this? is it natural?
Thanks!

I would not worry at all about the oil turning black. Black oil does not mean it is bad.

You can NOT look at the color of oil and tell if it is bad or not.

Change your oil in a sbc every 3000 miles for a daily driver.

Usually indicates excess blowby and a rich mixture I think. Does the engine use any oil?

Sometimes i can get around 4 to 5 miles on 8 quarts of Mobil-1 synthetic before it's pretty dark. WHen I was running methonol it would get white and milky in just 1-2 miles.
LMAO,,, don't sweat it. The contaminents get washed all through the engine and if your motor has ever seen some extended periods between oil changes, it will darken the oil quicker. And just like already stated, the majority of the comtaminents are from blowby, or from the oil cooking at the bottom og the intake manifold.
One time I tried to clean a nasty motor up by changing the oil every 200-500 miles (with a cheep oil and a bottle of some 'motor flush' crap). After 5 or 6 oil changes I thought I had done real good. Soon after oil pressure went real low, valve train got noisy, the motor had the sound of mains rumbeling,,, I decided dark oil isn't such a bad thing after all.

If yo want to clean it up, change the filter every week and add a quart of fresh oil. It takes a number of changes, but it really does help clean up a dirty motor.

I would not worry at all about the oil turning black. Black oil does not mean it is bad.

You can NOT look at the color of oil and tell if it is bad or not.

Change your oil in a sbc every 3000 miles for a daily driver.

Agree 100%. After being in the fast lube business for 14 years, I've seen it all. Dark oil means that it's doing as it is designed to do. Oil is supposed to "catch" all the contaminants produced by a running engine. It takes a LONG time before it loses its lubricity. 3000 miles is a good rule of thumb when using conventional oil. I wouldn't go much beyond that because oil can on only absorb so much contamination, then the rest is just cycled through the engine and reaks havoc. Even the "best" oil filter won't catch EVERY thing. Oil brand name isn't as a big concern like it used to be. EVERYONE has certain specs to meet before their products can be licensed to sell these days thanks to the EPA.

My buddies dad works for an oil company, Penn-Oil I believe. They make their oil out of PA crude oil. Anywho, he was telling me that black oil is good, means it's doing it's job of picking up dirt.

If it was bad the diesel guys would be in deep crap. All you've got to do on a diesel is idle it five minutes and your new oil turns black.

How many miles it takes for the OIL to get BLACK!

how dirty is your engine?

Modern detergent oil turns dark soon. Its doing its job.

Thank you all, I think I know so much about the OIL now, and will not be worry about this issue anymore!

If you want to check too see if your engine is running too rich, pull a couple of spark plugs and check the tips. If they are black and sooty, then your mixture is too rich, they should be a golden tan brown to indicate proper combustion. If they are golden brown, then your golden.........if black and sooty, you can lean out your carb mixture slightly then drive the car around some with fresh plugs and recheck. Good luck.

Never run a engine flush in a sludgy engine either. I can break up the sludge and clog stuff like oil galleys and the pickup.

Just change the oil every 500-1000 miles or so. The detergents in the oil will break the sludge down slowly and after several changes (3-5) the inside of the engine will be about as clean as its going to get.