Synthetic Oil

[casual]

I am purchasing a new used boat.The yard where the boat is at only uses synthetic oil,The engin is a Yanmar 4JH3E appx 3000 hours,I have no knowledge of PO oil type,Will synthetic oil do is it better than Castro GTX which I have always used in my present Boat?I am sure I could get some Castro oil somehow.This engin was making oil due to a bad lift pump,had oil analysis done all ok.Thanks for the help,PS this will be the first change after analysis

[Marksman]

Synthetic oil is great stuff, but perhaps not really required for marine use. It's all I use for the reasons outlined in my attachment. Everyone should read this as it dispells many myths about many oily subjects. It's a word doc as I copied and pasted from a web site.

[delmarrey]

One thing I do know about synthetics is you don't want to be making any oil. It brakes down the synthetic very quickly and will possibly damage the motor in short order. Motor oil can go almost 50/50 with diesel fuel before it gets too bad.

Machinery Lubrication May 2007

[casual]

Thank you delmarrey,that answer was not what I expected ,having had that experience once,must have been regular as engin check out.I will use only regular oil much appreciated,I wonder if this fact is well know?Thanks again

[delmarrey]

Actually any contaminate will degrade synthetic. That includes water and antifreeze. And biodiesel is worse. The synthetic people are just trying to push their product. Diesel motors use more oil then gas motors per size.

There are HD oils for diesels, which should be used! The crankshaft bearings on a diesel take a hellofalot more stress then a conventional high RPM, high temp gas motors. I use the Valvoline HD Diesel 15W-40 Premium Blue for my Yanny, but Delo 100 is popular.

http://valvoline.com/products/commer...ed-products/10

http://www.machinerylubrication.com/...cant-crankcase

[Jon Hacking]

Thanks, Delmarray. I didn't know that either. Now I read that Yanmar engines actually want mono-grade 40, not a multi-vis. We've got 4JH2CE engines w/6K hours & I've been using 15w40. Is that a problem?

We're also considering going with an external toilet-paper type oil filter as well as the spin-on. I can never get the last bit of oil out of the dip-stick tube, & that has much of the grunge in it, so our oil turns black quickly after a change. The TP filter should cure that, so I was thinking of switching to a synthetic, but now I realize that's not a good idea.

[delmarrey]

From what I've read about syn's is they're great with the low sulfur diesel fuels (not in marine/farm fuel) and one can get around 3% better fuel economy but is not good in older motors, for reasons mentioned above.

If your maintaining a black oil after changes, I'd suggest doing a compression/blowby test.

I don't trust those old TP filters. If a piece were to brake loose and plug a passage, who ya gonna sue. I would just flush out the oil pan a few times with diesel fuel, w/o running the motor. Dump the old oil back in, start/warm it up, and then change the oil.

IMHO A monograde would be fine for a motor where ambient temps remain fairly constant but for here in the PNW, I prefer a multigrade. Yanmar technology hasn't impressed me very much. Although the machine work is good.

I do use the monograde in the KANZAKI tranny. It needs the higher viscosity for the gears and ball bearings.

[Marksman]

Apparently no one read my attachment, or some of these comments would not have been made.

[moggie]

Thank you Marksman.
Good info!
Will stop a lot of bar "experts" !

[casual]

Marksman.I could not open your attachment,had to go back and get word reader,Now I have read your attachment,WHAT a wealth of information,I also ride a BMW R1200rt,nothing but red line since new,BMW says change oil every 6000 miles,I have been doing every 3000 miles,Is this an overkill?By the way I also have a 76 Triumph.I restored any oil that will stop leaks?Thanks for the input

[delmarrey]

Fred, That is a good little piece you put together there and I'm glad to see you put in the credits, even though it is directed towards motorcycles. Some of us do not have Word® doc so if it were in a pdf format it would be easier to open for some. The charts were a bit compressed for Pages® doc's.

Thanks!

[Marksman]

Thanks guys, wish I could take credit for that piece, but I only copied and pasted it from a motorcycle forum hence the word doc, but it certainly changed the way I buy and use oil. The author did his research for sure. I will try and get it into PDF to make it easier for others to read, knowledge is power.

Casual, IMHO which is worth exactly what you paid for it, 3k is not overkill if:

1) You only put 3,000 miles on per year making time in the crankcase a factor. (additive package expiring)

2) You spend a lot of those 3,000 miles at high rpm with heavy throttle. (VI modifiers and mechanical shear).

I ride a 2000 Roadstar with a big bore kit (108 cdi), rarely gets over 3,000 rpm, and a 76 Kawasaki 900 that (when I ride it on the odd occasion) see's 9,000 rpm frequently (under the right circumstances of course). I'm pretty sure the Kaw is tougher on the oil. Never had it tested, just my supposition.

Cheers guys

[LH44 Anne]

Sir:

PDF is much easier, as already noted. Since you don't appear to have the capability close at hand, I've taken the liberty of putting your document into PDF form. My software makes this easy and quick to produce. Hope you don't mind my preemption of your file. It seems well worth making it more widely available to folks who don't have Word or haven't downloaded the free Word Reader. And there's the folks on Apple and Linux who find doc files particularly difficult.

[Marksman]

Hey there Jim, again, I didn't write that article I just found it linked on a motorcycle forum. I did some research and found the original website and the fellow who wrote it. It may be better to post that rather than the text itself. I know, I already did but after finding the sorce and his request that we don't do that....hind sight.
The author's name is Mark Lawrance, here is a link to the article at his web site. All About Motor Oil

Cheers!

[Khagan1227]

Originally Posted by delmarrey

Actually any contaminate will degrade synthetic. That includes water

1. Most contaminates will reduce the performance of any oil. Not to mention the damage the contaminate can do to bearings, etc.

2. There are several synthetics out there (Royal Purple is one) that is not only NOT degraded by water, it will NOT emulsify like mineral oils and some synthetics. This allows the user to drain any water in the oil off and continue to use the oil with little or no loss of performance. Emulsified oil looses lubrication properties and heat removal capacity. If you are truely concerned about water in your oil, just like particulate filters, water filters are available to remove water.

If you are the type of sailor that rarely uses his engine, synthetic is a perfect oil. The PAOs in the oil will help the oil to cling to the internals of the engine far longer than mineral oils. Oil clinging to the internals of your engine will prevent corrosion, and more contaminants in your oil. Additional the "slick" properties of PAOs will reduce wear on your engine parts during cold starts, again reducing the amount of contaminants in your oil.

An additional benefit of a good synthetic oil, the viscosity changes much less over a very large temperature range, meaning if you sail from the Caribbean to Labrador, you most likely won't need to worry about the oil thicking.

IMO, the benefits of a good synthetic FAR out weighs the cost, and since the engine in most boats can be a significant cost of the boat, why not spend a bit more and treat it right.

Disclaimer: I am not employed by, nor affilitated with any oil companies or the sale of their products.