New oil..

[Wickedcummins]

I ran 5w-40 royal purple all year last year and loved the results. Went from the rotella and at the oil changes was coming out nasty.. all the times I changed with the royal purple it was about as clean as it went in.. And the oil samples from black stone came back 100% better also.. Showed zero material and said the oil like was still had 80% life left whooaw.. changed the oil every 50 hours. with both oils.. It might be the oil filter also. Anyways I run the 5w-40 due for much better start up flow and protection

[NICKYPOO]

That's good to know. Royal Purple makes good stuff. Personally, I've been running Mobil 1 5w-30 full synthetic forever now and it always looks great when I change it.

[chpthril]

isnt the Rotela a high-detergent oil formulated more for diesel? If so, then wouldnt it stand to reason that it has a higher concentration of cleaning additives and was doing more cleaning on the crankcase? When I steam clean my carpets, I want to see the water coming out looking dirty, compared to the clean water the steamer is spraying down. Dirty water in the catch-can tells me the cleaning solution is doing its job.

Are you running a different weight RP then you did the Rotela? Did you have some negative side effects with the rotela, like a blown engine, smoking, knocking, high oil consumption? Was there "material", metal, solids, etc, found in the samples of used rotela?

Just playing devils advocate, thats all. I do not use rotela and sure as hell will not use synthetic. Been there, done that, rebuilt engine due to froze rings.

[SBM1234]

5w oils worry me, especially for 350 CID motors. What is your oil pressure on a hot day when the engine is warmed up and idling? Granted that I have an '07 model with the MP engine, but the manufacturer recommends a straight 40w oil. I ran 25w-40 as a compromise so I don't have to worry about cold starts as much, but I don't think I have the nads to try a 5w.

[Wickedcummins]

You do under stand the 5w is the starting weight right? They all end up at a 40W warmed up lol

[Wickedcummins]

was high with silicon at 15ppm with rotella with royal purple dropped to 2ppm silicon is positive dirt contamination. not serious till 30-40ppm but I didn't like the numbers hence why I switch from sierra oil filter and rotella oil to the royal purple oil n filter. Iron also went from 22 down to 4. Just the results I have found

[SBM1234]

You do under stand the 5w is the starting weight right? They all end up at a 40W warmed up lol

I meant no disrespect by my comment, nor do I mean any with the following comment:

You should change the oil on a warmed up motor - one with 5w-40 and one with 15w-40 and see the difference. The 5w-40 will be less viscous - especially at the operating temperture of a boat which is about 50 degrees cooler than a car.

BUT, if your oil pressure is above 25 when idling, I think you may be onto something there.

[Wickedcummins]

I don't need to change the oil warm or hot I am telling you 5w is what it starts at.. Then as starts heating it heads towards 40 =) And yes at lower temps the 5w-40 will be thinner because it has a larger range of viscosity

[Wickedcummins]

The cSt is the unit of measure for viscosity and the lower the number the thinner the oil is at that temperature when comparing two oils at the same temperatures

I put together this graph to show the relationship between different viscosities (Valvoline again). You can see that at the low temperature test there is a huge spread in viscosity but as the oil warms up they get very close to each other. Keep in mind that at the right end of the graphs there is still significance between grades but the linear scale of the Y-axis makes it hard to see.

[Wickedcummins]

There is also another thing to consider with your oil in your boat and that's the normal operating temp. Some boats never get over 165-170. My boats a complete closed cooling system and never leaves 175 degrees .

[SBM1234]

Agreed, but does your boat operate at 212 degrees? Mine is more like 150 max, but again it is an 07 and I am not sure what the newer models run at.
So, if I am looking for max. vis. at the operating range (saying that 150 degress is the midpoint on your graph), the 20w-50 seems like a good choice as it is double that of the 5w-30.

Also, I looked and didn't see a Royal Purple 5w-40 that was FC-W certified. They do have a multivis 40 - was that the one you used?

[Wickedcummins]

Im not sure on the part number I orders 3 cases from RP direct. He said the stuff he sent me exceeds the owners manual recommendations. I posted it all in another thread last year. Boats are shut off and started so much I don't want oil in my engine.. I want something that flows real nice right away then reaches the thickness I want at my temp of 175 degrees. Worst bearing wear on an engine is cold starting. I want something that flows right away with more volume than waiting for my engine to warm up to get good oil flow!

[mnpracing]

this may be a stupid question, but if it starts at the lower number when cold, and ends up with a thicker viscosity when warmed, then why does the oil flow better when warmed up (easier to change oil on a warm engine)?

[Wickedcummins]

Go here and read its a great article

http://www.bobistheoilguy.com/motor-oil-101/

[SBM1234]

Im not sure on the part number I orders 3 cases from RP direct. He said the stuff he sent me exceeds the owners manual recommendations. I posted it all in another thread last year. Boats are shut off and started so much I don't want oil in my engine.. I want something that flows real nice right away then reaches the thickness I want at my temp of 175 degrees. Worst bearing wear on an engine is cold starting. I want something that flows right away with more volume than waiting for my engine to warm up to get good oil flow!

I am with you there. I get a little concerned about blowing seals too - shoot, when I start it up and its at like 65 psi I cringe thinking about the pressure on the seals!