Sorry, another oil thread

[a64pilot]

Originally Posted by Ecos

I think turbine engines use an Ester base synthetic oil? I don't think it works in anything but a turbine engine either.

I believe so, and have been told it will eat normal oil seals, but I don’t know.
I have also been told that if you cook with 23699 ( a turbine oil) that it will make you go blind. I was told that happened in Vietnam to some villagers, but it may be just legend

[Wotname]

Interestingly, Yanmar states a CB or CC service classification is suitable for this engine!

[Simi 60]

Why do some people insist on making something so simple into a drama?

If it meets spec you are good
If you change it at or near when they say you are good
Simple.

[hellosailor]

Both SAE and API explain their specs very nicely online.

A multiviscosity rated oil is designed to be thin when cold, because engines basically make the first few revolutions on the crankshaft (and everything else) when there is no oil pressure (unless you've been running a pre-start lube pump) and the oil has drained off everything into the pan. Saw the oil is (was) actually doing nothing on startup.

And the typical crankshaft is slightly smaller than the bearings is rides in, with a side force from the pistons pushing it unevenly, so it "slaps around" bouncing on the bearing surfaces until it has enough momentum, and a smooth cushion of oil, to keep it rotating smoothly.

A synthetic oil is also engineered for "thin film lubrication". That is, a very thin but functional oil film remains on the metal parts for hours, even overnight, compared to a conventional oil which will have drained off completely.

So now you have a multi-viscosity synthetic oil, which is still coating the metal surfaces and capable of lubing the parts on startup, or you have dino oil (even worse if it is not multi-viscosity) which is actually not present and lubricates nothing on startup.

Gee....Hard choice. And in the last 35 years, since Mobil1 opened up the synthetic market, all the viscosity stabilizers and other ingredients have improved, even in the dino oils. But the synthetics are still crafted "better".

The point a64 makes about a fine micron bypass filter isn't something the casual buyer would have any idea about, but it is just as important as the micron rating of your fuel filter. Maybe five years ago, Mobil had doubled the price of their Mobil1 oil filters overnight. And the competition was Mobil or Bosch, both sky high, versus the four dollar filters. (Okay, there was one cheaper popular name too.) One or the other of those two, I don't remember which, had a blurb on their box explaining that they didn't "just" filter down to a certain micron level, but that they filtered something like 90% of the particles down to 2 micron, versus other filters that were only rated to 50% at 20 microns, or something equally way out of the ballpark.
But hey, the market leaders don't want to confuse buyers by using those pointy Arabic numbers.

I use synthetic, and have used it since '85, because at that time a friend gave me the full press kit from Mobil including engine tear-down photos after fleet use in police and taxi engines. The engines with conventional premium oils all had the usual heavy black tar or coke on the valve covers, where it "cooks off" even after you shut the engine down. The ones with Mobil1? Yeah, clean shiny metal, no tar, no coke. And that means none anywhere in the engine. That sold me.

Maybe ten years ago Mobil touched back on that in a TV ad campaign, where they cooked oil in glass skillets, to show how the synthetic just didn't turn to tar under heat, when conventional oil does.

Of course, if you keep the engine block cool, and run your engine blower for ten minutes after shutdown so the oil isn't cooking after it has stopped circulating, and you have a pre-start electric oil pump (as flying boats did)...there's nothing wrong with dino oil. But if you've ever had a clogged oil passage or any other lube problem take down an engine, the extra ten bucks once or twice a year to go synthetic may seem like a very reasonable investment.

Now, if someone could please explain to me how one big-name company has "liquid titanium" in their premium synthetic oil, when titanium ain't liquid at any temperature me or my engine are likely to be functioning at....Please?

[a64pilot]

You know marketing is nothing but lies, it’s pretty simple. So you get caught and sued, and some slick Laywer gets to argue that it depends on what the definition of is, is.
Mobil and Castol lawsuit on what is synthetic oil, you may want to read on that, and find out why API no longer talks about synthetics, cause some Lawyer redefined what synthetic means.

Anyway a lot of bigger aircraft radial engines were prelubed. They had to be, they had 9 or more BIG cylinders all running on one main bearing.
However pre lubing was all the rage 40 years ago, and it all meant nothing at all for engine life, unfortunately. That and the newer cars that turn their engines off every time you lift You foot off of the gas has me questioning whether most all engine wear occurs at start up or not, to say nothing at all with the fact that automobile engines in Northern Wisconsin etc., last the same number of miles as one in Arizona or Florida?

If most wear occurred at start up, why aren’t the engines that cost a lot and have reputations of lasting forever, like a Gardner etc., prelubed?

[Wotname]

^^ and yet we are told that car engines which are rarely shut down (taxis etc) have really long engine lives??

[Simi 60]

Originally Posted by hellosailor

, the extra ten bucks once or twice a year to go synthetic may seem like a very reasonable investment.

$10 in toy motors
Not so in ones that take 40 litres to fill.

Plus for our engine we were warned away from it, to low a viscosity and a great way to start it leaking we were told.

[hellosailor]

a64-
I don't argue the points. The fellow who taught me about engine wear was a ocmbustion scientist. Two PhD's in the subject, from the Swiss Federal Institute, their version of MIT. He literally spent years looking inside combustion chambers through little quartz windows in the cylinders of engines. And his primary source of income was some patent royalty--on patents used in 90% of the diesel electric railroad engines at the time.
So, I think he knew his stuff.

Home much better or different engines have become (synthetic oil didn't exist back then) and what other issues may complicate the "obvious" answers, I don't know. But the main shaft of a conventional in-line engine still has to slam around in the bearings the same way on startup. Maybe they just have more durable metals these days, masking the problem. Maybe the engines in the frozen states last longer because, gee, the oil never overheats and tars up in subzero temperatures?(G)

Seeing all the fine instructions like "run one minute at ## for every minute spent at ##" makes me think an engine shouldn't have a throttle at all. That kind of engine needs an "Off-1-2" switch. Run it low, or high, or not at all, and at exactly the prescribed rpms, right? (sigh)

Perkins weren't made by pagan gods, but at least they don't have turbos! Personally, I just don't think I'm fast enough to play with anything spinning at 30,000 rpm.

[a64pilot]

Originally Posted by Wotname

^^ and yet we are told that car engines which are rarely shut down (taxis etc) have really long engine lives??

Yes, that has a lot to do with age I believe, both of the lubricant and of the engine. Plus of course no or few thermal cycles.

Airplane engine wise we are told that among the worst things you can do is frequent high power operation, and never, ever pull the engine from high power to idle, yet the engines that seem to last longer hours than any others, are often in trainers, that continually go from wide open take off and climb, to idle for the approach, repeat over, and over, day after day.
Just plain age takes its toll, taxi cabs and cops cars are also almost always on a rigorous oil change schedule too. A lot of personal cars get the oil changed when they remember and or there is extra money.
I’ve known people who lease cars that don’t change the oil, ever. Why waste that money?

[hellosailor]

I suspect the "engines that are rarely shut down" is a bit of confusion. It is not the engines that are running longer, but the VEHICLES.

From the same combustion engineer, the explanation of why long-haul truckers and other fleet operators simply left their engines running rather than shutting them down and restarting. Every time you shut down an engine, you throw electrical spikes. Up to 600v in a car, up to 2000v in a truck. Every time you start up, you throw more spikes, and because the starter is a high-impulse motor, you heat stress the starter. So besides thermal cycling the engine and anything else, you are throwing spikes and consuming the alternator and starter. And if either of those fails "the engine" has failed. If you are carrying $150k worth of fresh vegetables and your starter fails, that's cost you $150,000 worth of fuel you could have burned by just letting it run.

On changing the oil in a lease car? That was BMW's marketing genius, leases with ALL maintenance included, so there were no excuses not to do it. And, the dealers would remind you to do it, because the factory paid them to do it, and this ensured well maintained "Certified Pre Owned" cars for their used car inventory. AFAIK they were the only folks doing it that way, for years. They even used to change the windshield wiper blades, on request.

"The fuel is the cheapest part of an engine." May not feel that way, but it still is.

[David Hoyt]

Consider Royal Purple with Patron Plus additive.

[Carl-T705]

Sure Yanmar wants you to buy their branded oil, Harley Davidson wants you to buy their branded oil too, along with Ford, Motorcraft, etc etc, Why do you think that is? I asked the local Harley Davidson dealer where the secret oil reserve and refinery is for their "special" oil and didn't get an answer...
I believe the brand of oil filter is far more important than the brand of oil. In the end, it's the oil with the least trash in it that is the secret to component life. Engines that never reach operating temperatures for extended periods, will have problems with the best oils .
Some folks will study the label on a can of soup but never look at the label of jug of oil. I've run diesel engines for decades, when I research oils Shell Rotella was the first one ruled out, ( check the ash content on a jug for yourself) My oil changes involve 11 gallons per service, that's expensive. I now concentrate on filters and their life cycle.
If your noodling around on the web, search for: "Gulf Coast filters" it's a very interesting read.

[01kiwijohn]

I'd use any well known brand of 15W-40. Shell, Mobil, etc. Change every 100 hours. Cost should not be an issue as your only using 3 qts per change.
I use John Deere Plus 50 as it has a additive package that will allow me to run to 200 hours so that if I'm in an area where the situation dictates I will be overdue, it minimizes the adverse effects of doing so.

[MarkSF]

I noticed that the OP is in New England. That means that he might be able to take advantage of one benefit of the T6, which is lower cold viscosity, leading to better cold starting at low temperatures.

T4 is a 15w40, and T6 is a 5w40. That's a considerable difference at low temps. But they'd have to be very low to be noticeable.

But maybe the boat is on the hard if it's that cold, anyway.

[Simi 60]

Originally Posted by David Hoyt

Consider Royal Purple with Patron Plus additive.

I wonder how all those countless engines around the planet that can't access your particular koolaid* could possibly still be working without it.

Given its gimmicky purple colour *