Synthetic Blend in an Older Westerbeke?

[FF]

My fear is with a syn oil its better detergents could loosen decades of gunk that could block an oil line or overwhelm the filter .

Why bother?

If the ancient style oil was lubing the engine for decades , what would be gained with synthetic?

Why take the risk?

 

[catalinajack]

My fear is with a syn oil its better detergents could loosen decades of gunk that could block an oil line or overwhelm the filter .

Why bother?

If the ancient style oil was lubing the engine for decades , what would be gained with synthetic?

Why take the risk?

THERE IS NO RISK! The detergent levels found in all of today's oils, synthetic or dino are virtually the same. That would include the oil you are using. Geez. Did you not read slowmo's excellent technical explanation in Post No. 22?

 

[Cigatoo]

“Lubrizol, Chevron Oronite, Infineum, and Afton,. These companies spend hundreds of millions of dollars per year on R&D in this area.”

Do you mean no STP oil treatment?

 

[rslifkin]

As a note on Rotella, T6 is full synthetic, T5 is the blend.

 

[FF]

"THERE IS NO RISK! The detergent levels found in all of today's oils, synthetic or dino are virtually the same."

"Today's oil," the question comes from engines that used the factory correct oil for 30-40 years which is different from today's oil.

The oil packagers didn't spend millions on new oil formulas to eat exhaust products for nothing.

With old formulas of oil the detergents would hold the grunge and fines while warm in an operating engine , BUT the gunk would fall out of suspension when the engine stopped and cooled. Sure it may take a week or a month , but in decades there are lots of weeks when the engine is not used.Many have used a putty knife to scrape an oil pan clean.

"Backwards compatible" only means the older engines will not be harmed by using a new mix of additives.

I doubt it means old gunk in older engines will not be touched by the better detergents.

The concern is similar to fueling with bio fuel in an uncleaned fuel tank, and having decades of crap stripped from the tank walls and bottom rapidly.

Yes, post 22 is great info.


Personally I don't have a dog in this discussion. My 2 stroke DD 6-71 can never be used with 4 stroke oil.

 

[rslifkin]

Even with oils that didn't keep stuff in suspension all that long after shutdown, that wouldn't leave much buildup to worry about. Most of the crap would get filtered out while running, so any that settles would be minimal.

Usually when an engine is really gunked up, it's from either running non-detergent oil where a lot of junk never made it to the filter or from running oil too long or too hot where it starts to break down, not function properly as oil, cake onto surfaces, etc.

As far as FF's detroits, yes, they have specific oil requirements and specs to worry about that most engines don't. Basically, the rule is CF-2 rated SAE 40 unless its going to be run hot enough to need SAE 50. They do say an appropriate (CF-2 rated and high HTHS) 15W-40 can be used if better cold start performance is needed. Interestingly, they advise against 15W-40 in marine Detroits even though they say it's fine for non-marine. I wonder what the reasoning is?

 

[Nomad Willy]

I hear the synthetic group. I could go back to a Kedge anchor that is heavier too. But I’d much rather anchor w either of the two modern anchors I have aboard .. an Excel and a SARCA and lighten my boat up a bit. Also I’d need to be underway or tied up in a safe harbor using a Kedge as it likely to certainly wouldn’t hold my boat in the gales.

Sometimes modern is helpful and sometimes not. Most people never think about the real facts but consider it a fact that newer is better .. period. And they consider people like my that use straight 30w oil in my trawler engine to be stupid. Got a screw loose. no quoting allowed please.

In my cars I’ve used syn or dino oil depending on the car and how I run it. When I take my 06 Avalon to the dealer for an oil change they put MV dino oil in it. Since it is 5-30w I assumed it was syn oil but I’ve discovered it's not syn at all. But it’s not the dino oil of the 60’s. Nor is the straight 30w that I use in one older car and my boat. They have 30w oil in them but it’s not the 30w that I used in the 60’s that came in the cardboard “can”. Probably the only thing the same in the two oils (the 60’s and now) in a 30w oil is the viscosity. So it’s a modern oil in every respect ... just the same viscosity. That is modern in every respect used where a VI package is not necessary like our rec trawler boats and stationary engines that get pre-heated prior to starting.

But if half your oil was additive there wouldn’t be much oil left to lubricate your engine. Every time you add something else to your oil that is not a lubricant you loose lubricity. One can maximize the percentage of oil in their oil by using straight weight oil. If you warm up your engine before leaving port no VI is needed and no benefit would be gained by using it. It’s just not needed.

I appear to be an old man stuck in his ways but I don’t think so .. except for the old man part. Can’t escape that.

 

[Nomad Willy]

rslifkin wrote;
“Interestingly, they advise against 15W-40 in marine Detroits even though they say it's fine for non-marine. I wonder what the reasoning is?”

Perhaps it has to do w the DD engines used in the big sport fishing boats that actually get worn out quickly. No VI means more oil to do the job and every ounce counts running an engine that hard.

 

[NightCrawler]

For over 30 years I've run pure synthetic in everything I owned. My 4.0 liter Ford Explorer used 1 qt every 9,000 miles when I sold it with 165,000 hard miles on it. Same for a Ford 4x4 5.4 liter. That one was really driven hard and used for towing.
Two stroke mixed at 100:1 in mowers, weed whacker (that one was new in 1977 and has the original plug in it) outboards and. . .I raced Enduro on a punched out 360 Yamaha with it in the oil tank. Never a failure.
Our 6BTA's have nearly 6,000 hours on them. Use one qt every 200-250 hours. Oil analysis at 500+ hours came back Level 1 - basically zero oil breakdown, no soot or fuel dilution. That's my real world experience.

One point I haven't seen brought up is heat. Turbo shaft coking is a very real challenge for dino bones. It's one of the primary reasons all turbo cars require synthetic. Good synthetic won't cook at high temps. All jet engines run synthetic - due to tight tolerance and high temps.

 

[psneeld]

Wow...internet arguments versus reality.

How many times has the complete spectrum of oils been discussed as used with no problems.

Even engine rebuilders say it's not the oil but the cleanliness, filtration, change interval, etc more than the oil that counts.

 

[Open-d]

THERE IS NO RISK! The detergent levels found in all of today's oils, synthetic or dino are virtually the same. That would include the oil you are using. Geez. Did you not read slowmo's excellent technical explanation in Post No. 22?

I don't understand this inordinate fear of synthetics.

Synthetics are "manufactured" and as such, the molecular chains are much more consistent in length. This length give viscosity. Dino oil has a mix of different lengths that gives an average length and hence viscosity, However, the long ones tend to break, reducing viscosity.

From a performance standpoint synthetics beat the pants off of dino oils in at least 3 categories.

1. Lubricity. The film strength of synthetics is about 6 times higher (3000 psi vs 500 psi) Better lubricity means less wear and less fuel used to overcome friction.

Dino oils have additive packages that provide secondary source of film strength, bismuth or something, can't remember, that is there to provide some lubrication when the oil itself fails to maintain that critical film of oil that keeps metal-on-metal from occurring. However, those packages wear out and hence the shorter oil change intervals for dino vs synthetics.

2. As discussed above, synthetics have a longer change interval because they don't need the additives that dinos do to maintain lubricant-films in extremes.

3, Due to the way that synthetics flow (turbulent vs laminar), they do a better job of coiling critical parts that are cooled by oil like journals, wrist pins etc.

One disadvantage to synthetics is that because they are more consistent at the molecular level they tend to be able to leak out of engines through tiny pathways that dinos couldn't. It isn't that they damage seals, they just can leak past them.

I use synthetics exclusively in my vehicles including synthetic grease for wheel bearings.