8.1L Vortec Napa Gold 7099. Bits/grit

[Gasbuggy]

Oh no, that would be way too cold assuming the gauge is working. The things needs to be hot, or at least hot enough and synced with the computer at that temp to be recognized as "warmed-up". Fuel trims will never be right. Unless you change the parameters in the computer. That bad boy should be right at 200-208 all day.


Or course, the boat engine is different than land based engine, and the use is different. You dont run around at 4000 rpms constantly do you? Only anaylsis can say that 15w50 works for your engine. Not sure I would go that thick. Point is, you have a couple of incompatible notions going on. May explain the black nasties in the filter.

nice looking truck

Change the thermostat back to factory, just run the AC delco filter. They are cheaper and just as good.

Marine engines were identical, from what I gather. Only potential difference could be a cam if you ordered it from GM performance. But springs/lifters are the same. Everything else is identical. If the internals and tolerances are the same would it be a problem at lower RPM but not higher? GM slapped use 5w30 on everything from the era.

Thee 8.1.expert, Raylar Performance, says 15w40 HDEO is the weight to use in these from stock to 800hp. I'll have to look and see how mobile PCMO 50wt compares in viscosity to run of mill HDEO. I'm not opposed to switching, but I do have a good bit of 15w50 to use up.

If the fuel trims are affected it somehow has not hurt fuel economy. My average is above average.

If you run 5w30 it will consume a consider amounts of oil because of the flawed PCV design. Pulling the intake to weld in a extension tube to remedy is not something I was interested in doing currently. If you click and scroll it will show a picture. If I have it apart I would consider it.

 

[burbguy82]

Marine engines were identical, from what I gather. Only potential difference could be a cam if you ordered it from GM performance. But springs/lifters are the same. Everything else is identical. If the internals and tolerances are the same would it be a problem at lower RPM but not higher? GM slapped use 5w30 on everything from the era.

Great,
But that has nothing to do with what I was talking about. My post was about the usage and water temp, and engine tune.

Point is ,how the engine is run makes all the difference in those things. Just because they run 15w50 and run a 160 tstat in a race boat does not mean you should do the same thing in your daily driver.

 

[350Rocket]

Marine engines were identical, from what I gather. Only potential difference could be a cam if you ordered it from GM performance. But springs/lifters are the same. Everything else is identical. If the internals and tolerances are the same would it be a problem at lower RPM but not higher? GM slapped use 5w30 on everything from the era.

Thee 8.1.expert, Raylar Performance, says 15w40 HDEO is the weight to use in these from stock to 800hp. I'll have to look and see how mobile PCMO 50wt compares in viscosity to run of mill HDEO. I'm not opposed to switching, but I do have a good bit of 15w50 to use up.

If the fuel trims are affected it somehow has not hurt fuel economy. My average is above average.

If you run 5w30 it will consume a consider amounts of oil because of the flawed PCV design. Pulling the intake to weld in a extension tube to remedy is not something I was interested in doing currently. If you click and scroll it will show a picture. If I have it apart I would consider it.

If it solves the oil usage I would keep doing what you're doing. I'm sure the chunks have nothing to do with the viscosity you chose.

 

[Gasbuggy]

Great,
But that has nothing to do with what I was talking about. My post was about the usage and water temp, and engine tune.

Point is ,how the engine is run makes all the difference in those things. Just because they run 15w50 and run a 160 tstat in a race boat does not mean you should do the same thing in your daily driver.

Guess what thermostat the identical marine engines run? 160.

This might even be how someone pieced together the cure. Their 8.1 truck burns a quart every 1000 miles while towing their 8.1 boat that burns none. The only two differences, the thermostat and the oil. Guilty of noticing.