The oil is not even 3,000 miles

[70' GMC]

The oil is already black as smut, and I had the motor rebuilt over the summer. Should I change the oil or what???

[60ratrod]

well it is going to depend on a couple of things. but yes i would change the oil. how long has your truck been sitting?? one thing that i would do if you don't drive it that much is go out like once every two weeks and run her for about 20 minutes or so just to keep the fluids flowing. with most conventional oils, they degrade with just sitting as well as running. synthetics usually don't degrade and turn black with just sitting in the motor.

[70' GMC]

Originally Posted by 60ratrod

well it is going to depend on a couple of things. but yes i would change the oil. how long has your truck been sitting?? one thing that i would do if you don't drive it that much is go out like once every two weeks and run her for about 20 minutes or so just to keep the fluids flowing. with most conventional oils, they degrade with just sitting as well as running. synthetics usually don't degrade and turn black with just sitting in the motor.

I drive the truck every day. I drive the truck to school to work, and around town. I buy the 10w-40 havoline deposit shield.

[see ten]

Oil is cheap compared to engines. Just change it.

[60ratrod]

i don't know the quality of halvaline, but what i use in all of my stuff is mobil1 clean 5000. my dad recommended it to me and have been using it ever since. when i pulled the pan on my 60, there wasn't any sludge build at all. i think 10w40 is a little too heavy for a fresh motor. 10w30 should work out just fine.

[Longhorn Man]

your oil will be black, period.
I would be more concerned if it wasn't... that would mean all the crap is in the engine.
Don't use a crap filter... get a good one.

[ChevLoRay]

Originally Posted by Longhorn Man

your oil will be black, period.
I would be more concerned if it wasn't... that would mean all the crap is in the engine.
Don't use a crap filter... get a good one.

Oil that doesn't get dirty, isn't containing the contaminants that get into the oil. The oil companies go to a lot of "trouble" to create oils that will grab onto and hold those contaminants in suspension, which causes oil to "get dirty". Detergents in the oil are what cleans the inside of the engine. Condensation and fuel that washes past the rings are part of what contributes to the dirty oil we see, along with the dirt that is within the air that the engine moves around inside the block. Oh, you didn't realize that an internal combustion engine is just a big air pump? The air filters are supposed to reduce the airborne contaminants, but they don't totally eliminate them. The PCV valve, in conjuntion with that funky little filter associated with the crankcase ventilation system, allows for that air to infiltrate the crankcase, where (hopefully) the oil WILL grab onto and suspend that "dirt" until your next oil change. Short trips, like those of 10 miles or less, don't allow the engines to warm sufficiently to allow the condensation to evaporate completely.

Hope I didn't bore you too much.

[Sport/Truck]

Originally Posted by 60ratrod

well it is going to depend on a couple of things. but yes i would change the oil. how long has your truck been sitting?? one thing that i would do if you don't drive it that much is go out like once every two weeks and run her for about 20 minutes or so just to keep the fluids flowing. with most conventional oils, they degrade with just sitting as well as running. synthetics usually don't degrade and turn black with just sitting in the motor.

I doubt oil just sitting will turn black….if so, then there will be a shelf live on new oil.

Originally Posted by ChevLoRay

Oil that doesn't get dirty, isn't containing the contaminants that get into the oil. The oil companies go to a lot of "trouble" to create oils that will grab onto and hold those contaminants in suspension, which causes oil to "get dirty". Detergents in the oil are what cleans the inside of the engine. Condensation and fuel that washes past the rings are part of what contributes to the dirty oil we see, along with the dirt that is within the air that the engine moves around inside the block. Oh, you didn't realize that an internal combustion engine is just a big air pump? The air filters are supposed to reduce the airborne contaminants, but they don't totally eliminate them. The PCV valve, in conjuntion with that funky little filter associated with the crankcase ventilation system, allows for that air to infiltrate the crankcase, where (hopefully) the oil WILL grab onto and suspend that "dirt" until your next oil change. Short trips, like those of 10 miles or less, don't allow the engines to warm sufficiently to allow the condensation to evaporate completely.

Hope I didn't bore you too much.

If you are using a K&N air filter you will get more dirt than usual…..specially if you drive on dirt roads.
You can send you oil in for analysis and see exactly what is wrong with it. Otherwise its just speculation on what is going on. I use Blackstone, there kit is free and the test is reasonable.
s/t

[special-K]

The oil is not even 3,000 miles??? Did you change it since the rebuild?Should have at least by 500 miles.If it`s been since summer it would be black by now that`s for sure.One thing that will break oil down faster than miles ran is high revving such as when doing burnouts...The 3,000 mile recommendation is for "normal" driving.That figure gets decreased by multiple variables.

[truckdude239]

did you change it after 500 miles use a good filter i run puraltor filters or ac delco wix and napa are also good, i mosty run the puraltor filters. run something like 10w30 mobil drive clean or gastol gtx

[hotrod 80]

My engine builder gives everyone he machines a motor for a tube of the black moly assembly lube with the newly machined parts . If your engine builder used this when he assembled it then that may be what you see . That stuff stick around for a while . I installed the rear seal backwards on one motor and had to drop the pan . That black assembly lube was at the bottom of the pan .

[70' GMC]

I used the most expensive napa oil filter, the color was black, I don't know what that one is, and I changed the oil 2 or 3 months back. My uncle said dumb a double s, why aren't you keeping up with the miles? I asked him what did he mean, he said you drove all over whiteville, to work, to wilmington, and not to mention all the driving you did while you were up there. I did not know that I should have changed the oil at 500 miles, I never ever heard anyone say that it should have been changed at 500 miles. I hope I did not mess up the motor? did I?

[Sport/Truck]

Originally Posted by 70' GMC

I used the most expensive napa oil filter, the color was black, I don't know what that one is, and I changed the oil 2 or 3 months back. My uncle said dumb a double s, why aren't you keeping up with the miles? I asked him what did he mean, he said you drove all over whiteville, to work, to wilmington, and not to mention all the driving you did while you were up there. I did not know that I should have changed the oil at 500 miles, I never ever heard anyone say that it should have been changed at 500 miles. I hope I did not mess up the motor? did I?

FWIW NAPA filters are WIX. It a good one to use IMO.
The reason to change the oil so soon is to remove the breaking lube & any metal that is in oil from the break in.
Isn't it recommended you change the oil after the 20min cam break-in?
s/t

[streetstar]

Its a small block Chevy --- you shouldn't have messed it up too bad by going past 500 at break in.

But now you know the guidelines so it wont happen again. Its pretty normal for oil to be black after 3000 miles too - no big deal - just change it and the filter and drive on

[70' GMC]

When I was little all my dad would buy was halvoline oil, and fram air, oil, and fuel filters for the car and his 70 GMC.

[90\87Formula]

70'GMC, What are they teaching you in the AutoTech class?

[70' GMC]

Originally Posted by 90\87Formula

70'GMC, What are they teaching you in the AutoTech class?

Engine theory, and something about the electrical wires fuses, etc., etc. Then something about hooking stuff up to a computer and diagnosing the problem.

[Billla]

Originally Posted by 70' GMC

When I was little all my dad would buy was halvoline oil, and fram air, oil, and fuel filters for the car and his 70 GMC.

I was the same way on Valvoline and Fram - unfortunately, both have proven to be less than optimum choices for our trucks. WIX/NAPA filters for sure, and an oil with a higher ZDDP content is highly recommended (see other threads on this)

[streetstar]

oil is oil, just keep it fresh and topped up. There are variances in filter quality, so it pays to spend the extra .50 for a good brand -- but even the cheap house brand oils are miles ahead of oils used when your truck was new.

At least thats what i was taught in A&P school, - and concerning engines with consequences much more dire than just being stranded if they fail

[Sport/Truck]

Originally Posted by streetstar

oil is oil, just keep it fresh and topped up. There are variances in filter quality, so it pays to spend the extra .50 for a good brand -- but even the cheap house brand oils are miles ahead of oils used when your truck was new.

At least thats what i was taught in A&P school, - and concerning engines with consequences much more dire than just being stranded if they fail

Ok, how often do they recommend oil changes? Do they use a month schedule along with the hour meter? They also do oil analyses too, don’t they?
I wonder what they would say if you put in Flag non-detergent oil, or a recycled oil of some type? – they are all the same…..

s/t

[streetstar]

Originally Posted by Sport/Truck

Ok, how often do they recommend oil changes? Do they use a month schedule along with the hour meter? They also do oil analyses too, don’t they?
I wonder what they would say if you put in Flag non-detergent oil, or a recycled oil of some type? – they are all the same…..

s/t

Ask a crop duster or a member of the CAP--- you would be shocked ------ IT JUST DOESNT MATTER ------ as long as its fresh and topped up and as long as you don't mix synthetic with mineral.

Viscosities mix readily ------- Auto people lay much more importance on this b-s than av people ---- but i'm talking about people who use their planes hard, not folks with a Pitts Special who uses it 10 hours a month. A plane is a big investment, and many people rightfully treat their investment like i would treat a Lotus -- but in either case, its not totally necessary , but owners do what owners do

[89 crew]

Originally Posted by streetstar

Ask a crop duster or a member of the CAP--- you would be shocked ------ IT JUST DOESNT MATTER ------ as long as its fresh and topped up and as long as you don't mix synthetic with mineral.

Viscosities mix readily ------- Auto people lay much more importance on this b-s than av people ---- but i'm talking about people who use their planes hard, not folks with a Pitts Special who uses it 10 hours a month. A plane is a big investment, and many people rightfully treat their investment like i would treat a Lotus -- but in either case, its not totally necessary , but owners do what owners do

Av gas has the advantage of lead. While yes these trucks were designed for lead they were not designed for surfer which replaced lead. start putting gas station gas in your plane and see how far you get! That is the reason for the different opinions! While the recycled oil, and non detergent oil will work fine with lead, they won't work with the sulfur based fuel we are forced to burn in our trucks without something to stop the sulfur from becoming sulfuric acid. without the additives, sulfuric acid will eat your engine from the inside. try what they said and then let it set for 1 month and you will have pits in the cam, lifters, crank, and bearings where the oil stayed in contact. that is the purpose of the detergents in the oil, to stop it from causing problems.

[Billla]

Originally Posted by streetstar

Ask a crop duster or a member of the CAP--- you would be shocked ------ IT JUST DOESNT MATTER ------ as long as its fresh and topped up and as long as you don't mix synthetic with mineral.

Viscosities mix readily ------- Auto people lay much more importance on this b-s than av people ---- but i'm talking about people who use their planes hard, not folks with a Pitts Special who uses it 10 hours a month. A plane is a big investment, and many people rightfully treat their investment like i would treat a Lotus -- but in either case, its not totally necessary , but owners do what owners do

Probably going OT, but I call complete I don't know anyone that owns their own aircraft that doesn't use a top-quality aviation oil.

[streetstar]

Originally Posted by Billla

Probably going OT, but I call complete I don't know anyone that owns their own aircraft that doesn't use a top-quality aviation oil.

Sorry about the thread hijack, i just found the plot twist interesting.

Most people would use only the best i agree, -- when you have 75 - 200k (or more) investment - $100 for a case of oil is no big deal -- but not all

My father worked for the FAA for 30 years as a field safety investigator. I worked as an apprentice doing the same before settling down at Cessna in their experimental department. Part of the job with the FAA is dealing with the low budget operators(cropdusters, CAP people, low budget cargo operators) and type certifying home builts and things like that. In that environment you see anything and everything and you quickly learn there is more out there than hobbyists with their Mooneys and Bonanzas sitting in brightly lit hangars with checkerboard floors.

In the experimental dept., we tried everything in a somewhat controlled setting to get planes to fail as well in both static and flight tests

I haven't seen it all, but i have seen a wide range of oddball setups (the worst is the crop dusting field -- where a plane is regarded as a tool, no more or no less important than a tractor)

I have as much respect for a horizontally opposed Lycoming 4 or Continental 6 in the durability department as i do any small block chevrolet

[Billla]

Originally Posted by streetstar

oil is oil, just keep it fresh and topped up. There are variances in filter quality, so it pays to spend the extra .50 for a good brand -- but even the cheap house brand oils are miles ahead of oils used when your truck was new.

At least thats what i was taught in A&P school, - and concerning engines with consequences much more dire than just being stranded if they fail

Keep in mind that aero oils are held to MUCH higher standards that automotive oil...and it's typically changed every 25 hours (~1500 miles if we think 60 statute miles/hour). The standard small aircraft air-cooled engine also uses significantly more oil than a standard car as the bore clearances and ring gaps are much wider - it's not all that unusual to add a qt after 2-4 hours of flying depending on the age of the aircraft. Finally, most aircraft engines have 12 qts or more...so the filter is doing more work and a better job. I change my oil in my bird, and I'd sure never use anything other than AeroShell!

It ain't apples to apples, and oil quality certainly DOES matter in a daily-driven SBC - especially with a flat-tappet cam!