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Rawze · 04-29-2018, **(Subject: What would cause black oil in a tuned engine )**

(04-29-2018 )Chamberpains Wrote: Do you have a bypass filter on it? My new long block turns oil black around 10,000 miles with a MommaBurt tune and without a bypass filter. I have to sample this one cause i think it turned black a little fast. But this was also the first time I used gear lube in it. And I'm at 45,000 on it so 1st overhead adjustments are about due.

That sounds about right for one if it is much more than 450hp or so.

Mine stays light brown so long because I am a hypermiler and have the engine set for max fuel economy at the expense of more power. I also keep everything in very good shape for it too. A higher hp engine (485+ hp or more) set to burn the fuel too cleanly can actually be kinda risky.

I.E.> There is no "one size fits all" standard or measurement on the oil color. It is like asking "how much rain is too much" when you don't know any of the details of where on the planet it is raining.

Nilao · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

If I check mine while it still warm it's honey colored. If I check it again in the morning before I start it it will be real dark brown at 15k miles.

Chamberpains · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

(04-29-2018 )Rawze Wrote:
(04-29-2018 )Chamberpains Wrote: Do you have a bypass filter on it? My new long block turns oil black around 10,000 miles with a MommaBurt tune and without a bypass filter. I have to sample this one cause i think it turned black a little fast. But this was also the first time I used gear lube in it. And I'm at 45,000 on it so 1st overhead adjustments are about due.

That sounds about right for one if it is much more than 450hp or so.

Mine stays light brown so long because I am a hypermiler and have the engine set for max fuel economy at the expense of more power. I also keep everything in very good shape for it too. A higher hp engine (485+ hp or more) set to burn the fuel too cleanly can actually be kinda risky.

I dont wanna hijack.

MommaBurt has it set at 450hp. The original cal for a 435ST CM870 engine. We were talking about advancing the timing on it. He said it looked slightly retarded. I have no need for more power and fuel mileage is the goal. Will advancing timing affect fuel consumption and possibly clean up the fuel burn? Which inturn will keep my oil clean longer?

Hammerhead · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

(04-30-2018 )Chamberpains Wrote:
(04-29-2018 )Rawze Wrote:
(04-29-2018 )Chamberpains Wrote: Do you have a bypass filter on it? My new long block turns oil black around 10,000 miles with a MommaBurt tune and without a bypass filter. I have to sample this one cause i think it turned black a little fast. But this was also the first time I used gear lube in it. And I'm at 45,000 on it so 1st overhead adjustments are about due.

That sounds about right for one if it is much more than 450hp or so.

Mine stays light brown so long because I am a hypermiler and have the engine set for max fuel economy at the expense of more power. I also keep everything in very good shape for it too. A higher hp engine (485+ hp or more) set to burn the fuel too cleanly can actually be kinda risky.
I dont wanna hijack.

MommaBurt has it set at 450hp. The original cal for a 435ST CM870 engine. We were talking about advancing the timing on it. He said it looked slightly retarded. I have no need for more power and fuel mileage is the goal. Will advancing timing affect fuel consumption and possibly clean up the fuel burn? Which inturn will keep my oil clean longer?

Yes it should. Also part of the oil color is the fact that you have an 870. The VGT control is t as precise with their air actuated turbo compared to the electronic VGT of the 871 & later.

Rawze · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

(04-30-2018 )Chamberpains Wrote: ...a 435ST CM870 engine.
...
I have no need for more power and fuel mileage is the goal. Will advancing timing affect fuel consumption and possibly clean up the fuel burn? Which inturn will keep my oil clean longer?

On my old car with the 350 Chevy engine in it, I used to have 2 notches marked on the distributer. One for fuel mileage, and one for power. It is nothing new, guys used to do things like that all the time on older cars.

Yup. Within reason, the more you advance the injection timing on just about any piston type engine ... car, motorcycle, truck, even a lawn-mower, the higher the fuel mileage will get.

The trouble is that at some point, it becomes A RISK OF CAUSING DAMAGE due to high detonation and other things if it is not kept well in check.

This guy sums it up quite nicely about too much timing advance at 6:48 in the video ...
https://youtu.be/sATO6kfi_VY

In his video he sets it to +12 degrees. -- Back in the day on those old 350's, Most of the guys I knew used to set em to +14 to +15 for maximized fuel mileage, and down to +6 to +8 for when they needed a lot of power so that the engine would run a little cooler internally and to reduce internal friction.

I know lots of guys who use advanced injection timing settings and set them close to the upper edges of safe levels,.. but still end up loosing the engine. This is because you cannot predict a bad spray pattern on an injector, or other fuel related problems in the cylinders that can send it over the edge. What good is it when you save some fuel if it costs you a re-build?.

Lastly, injection timing settings also go hand in hand with fuel air mix, power and torque, rpm, intake temps, compression ratios, and about 200 other factors.

Here is an example of someone adding too much injection timing to an ISX even when it had a decent tune in it ...
http://rawze.com/forums/showthread.php?t...7#pid13847

04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

870's are very hard to get clean and stay there. they are older engines with older parts and have a very slow acting VGT which makes them slightly less efficient and that translates to darker oil quicker.

your fuel mileage also has a direct correlation to how dark your oil is and how fast it changes. the higher the mileage the cleaner it will be and vice versa. What you pull and duty cycles and condition of the engine also play big roles. the fct that your oil is staying clean for 10000 miles on a 870 is fairly impressive by itself.

Uni

Chamberpains · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

10,000 miles and the oil looks exactly the same as my 03 Duramax oil at the same mileage. I have no complaints thanks to Uni and MommaBurt. Outstanding work boys! Im just jumping on tree98's curiosity and running with my own engine and questions. Im really not sure which engine he was bringing the topic up about.

tree98 · 04-30-2018, **(Subject: What would cause black oil in a tuned engine )**

(04-30-2018 )Chamberpains Wrote: 10,000 miles and the oil looks exactly the same as my 03 Duramax oil at the same mileage. I have no complaints thanks to Uni and MommaBurt. Outstanding work boys! Im just jumping on tree98's curiosity and running with my own engine and questions. Im really not sure which engine he was bringing the topic up about.

870 but really I'm just curious about it in General