Oil grade

[gonesailing13]

I’ve been using straight 30W Rotella oil in my Lehman 135. Had some engine work done on the boat and my mechanic told me i should be using a heavier oil. Not sue what to go with.

 

[Old Sea Dog]

I have a 120. Use straight 30 Rotella. If I were to go with a heavier weight it would be a multi viscosity to 40. If you were to operate at lower ambient temps, then a multi would be best.

 

[mvweebles]

I ran Delo 30w for years in my old Perkins 4.236. I now run Rotella T5 15w-40w.

Here's a decent thread on the 3 major/relevant Rotella formulations.

https://www.trawlerforum.com/forums/showthread.php?t=67262

Honestly, 40w seems pretty thick for a water cooled engine. Many years ago I used to run 50w in my old Triumph Bonneville motorcycle when I was screaming through through the Utah desert. Not sure what I'd run these days, but would be some sort of multi-vis.

Peter

 

[Comodave]

30 weight is what Bob Smith recommended when I took his seminar.

 

[rslifkin]

I see no reason not to use a 15W40. Modern multi viscosity oils are far better than they used to be, and there's rarely a reason to use a straight weight in my mind.

 

[alormaria]

Do wat de book sez.

 

[mvweebles]

Do wat de book sez.

Here's the challenge. The "book" is over 40 years old these days. The oil certifications it would have recommended have long since been superceded. But probably would say something along the lines of straight 30-weighr.

So do you do what the book says, or do you use what the book would say if written today, which is likely some flavor of 15-40 that is API/CJ-4 rated?

Peter

 

[Shrew]

Does the winter weight on a multi-weight oil really matter when its 85 degrees out? I never run the boat below 50 degrees F.

 

[rslifkin]

Does the winter weight on a multi-weight oil really matter when its 85 degrees out? I never run the boat below 50 degrees F.

Yes, it still does. The viscosities are spec-ed at 40* C (104* F) and 100* C (212* F). So a 15W40 is thinner than a straight 40W at startup even if it's 85*.

 

[alormaria]

The bearing clearances and seals were designed to a specific viscosity oil spec.
Old original engines like the oils they grew up with. Deviate from that at your own peril.

 

[rslifkin]

The bearing clearances and seals were designed to a specific viscosity oil spec.
Old original engines like the oils they grew up with. Deviate from that at your own peril.

Every engine has a range of viscosities it'll be happy with. As long as the viscosity is appropriate and the additive package is sufficient, the engine will live a long, happy life.

 

[mvweebles]

The bearing clearances and seals were designed to a specific viscosity oil spec.
Old original engines like the oils they grew up with. Deviate from that at your own peril.

A year or two ago, Project Farm did a side-by-side test of engine oils HERE. One of his viewers sent a can of Quaker State from the 1950s which was included in the tests for kicks. Now, some argue about the efficacy of a test like his, but nit-picking aside, the results show just how far oil has come. Also explains why oil slingers on engines used to get gummed-up.

Here's a visual for you: you own a 1957 Chevy Bel Air that has been failthfully restored to original condition - matching number Blue Flame 6 engine, concours winner, the whole shebang. Given a choice, would you grab a case of 1957 Quaker State (or Penzoil----whatever) because that's what the engine was designed to use?

Peter

 

[Comodave]

Like I said in a post above, Bob Smith recommended 30 weight in the last seminar he taught. Brian did also. However the PO of our current boat at the time had been using 15W40 for 15 years with no apparent problems so I continued using it also..

 

[High Wire]

You should have engine heat or be in the tropics to use straight SAE 40. Yes, 60F is still a cold startup.

 

[jleonard]

I had a conversation with Bob Smith at a MTOA rendezvous in Mystic in 2010 and he admitted that 15-40 is fine for the Lehman. ( most of us were using it anyway)
I know my previous owner used it and so did I.

 

[Eli27]

Just had this conversation with Brian @AD. If you not in the bahamas you should use 30. If your in the hot tropics you can go with 40.

He was saying how the multi really messes with oil pressures and has people wondering about there engines conditions.

My opinion being a mechanic, stick with what the master says. And Master Brian say runneth only 30. I run 30.

By the way, don't buy oil from west marine,,, they are waaayyyyyyy over priced. 34 dollars for Rotella t1 30. 17 at WM.

 

[psneeld]

Sure seems like lots of people run the modern 15W40 oils and have never had issues after thousands and thousands of hours.

I think this is another one of those legends that may need more scientific proof than just "legend opinions".

The longer I "hear" conversations with American Diesel...... and the conversations I have had with others with tons of Lehman experience...never just discount other expert opinions....American Diesel is great, but some of the info seems weak against other expert opinion and the reality of other's experience.

 

[Bacchus]

I like and go by the Cox Eng recommendation for yacht engine oils.
See their report at
https://dkloeber.wixsite.com/bacchus/links Cox Eng Yacht Eng Oils

The most recent API grades were developed for engines with modern OTR emissions systems which are not present or applicable to our marine applications.
Cox is not even a proponent of synthetics for marine applications.

 

[Bacchus]

Sure seems like lots of people run the modern 15W40 oils and have never had issues after thousands and thousands of hours.

I think this is another one of those legends that may need more scientific proof than just "legend opinions".

The problem is that almost all of the " scientific " studies cited do not have any relation to marine engines or their use... OTR, pickup truck diesel applications are different, so quoting those studies carries little weight in my thinking... others have the right to swear by them or at them... always your choice.
All diesels are NOT uniform nor do mfgrs recommend the same.
I dont think a modern engine oil will necessarily kill an older engine... just may not be optimal.

 

[psneeld]

On this topic, I will stick with anecdotal info as there is not a lot of scientific studies out there.

The bottom line is I have never heard of someone running any of the better grade 15W40 oils in the older diesels and having a problem they can trace back to the oil before the engine died of other causes.

If that info is out there, I would love a link to it for future reference and to change my tune.

 

[JDCAVE]

30 weight is what Bob Smith recommended when I took his seminar.

Yes. He recommended Rotella SAE 30 and that’s what I use.

 

[jleonard]

I’ve posted oil sample results in the past. 15-40 does good. Proof in the results.
But I have never read any incident of engine failure from running a properly rated oil.
Heck I ran Castro 20-50 in my old Perkins T6.354 because it stopped most of the oil leaks. It was actually listed as a choice in the operator manual.

 

[rslifkin]

On this topic, I will stick with anecdotal info as there is not a lot of scientific studies out there.

The bottom line is I have never heard of someone running any of the better grade 15W40 oils in the older diesels and having a problem they can trace back to the oil before the engine died of other causes.

If that info is out there, I would love a link to it for future reference and to change my tune.

Agreed. As long as the oil is generally suitable for the engine in question, changed at a reasonable interval, and the engine doesn't have any particularly challenging requirements for oil, it's unlikely that oil will be the cause of the engine wearing out.

 

[Delta Riverat]

Yeah. Especially with 4 gallons in the sump.

 

[Mambo42]

My mechanic advises 15-40 mineral oil and that is what I have been using ever since. So far have no problems with it.
As for the temperatures, unless you ER gets very cold in winter time and you plan to use the boat in that period I would stay with one oil grade. A boat engine is not like a car engine, which can be subjected to sub zero temperatures overnight. In a boat the ER rarely gets below 10 degrees Celsius and once the engine runs it runs at a constant 78 degrees Celsius (at leat ours does). Temperature is being regulated by the thermostat and that is regardless of the water temperature.

I can understand that, when a car engine is subjected to very low temperatures, you will need a thinner oil than during summertime, but i.m.o. that does not really apply to boat engines. I even have a heating radiator in the ER to keep the ER at a normal temp if we would ever decide to go into freezing temperatures.

 

[mvweebles]

The more I think about it, the more I think it makes little difference whether you run straight 30-weight or multi-vis, as long as it's a modern oil with API/CJ-4 certification for Diesel.....at least for these vintage engines such as the FL 120/135 and Perkins 4.236/6.354. These were all designed before the advent of highly specialized oil formulations specific to an engine. The oil available when they were built was a distant knuckle-dragging cousin to modern lubricants.

A good friend of mine has spent the last 25-years working in marine propulsion for Deere, Alaska Diesel/Lugger, and now Northern Lights. Like myself he favors older trawlers from classic designers - his has a Perkins 6.354. He runs 15-40, though not sure if it's conventional, synthetic, or a blend.

In the end, I know of no one who has or is close to wearing-out an engine. In our type of use, engines are killed by Kamikaze bolt-ons such as water pumps. For those of us with older engines, sure seems like topic of oil is an interesting but near-meaningless discussion.

Peter

 

[psneeld]

I believe one of the manuals for the Lehman blocks (could have been the Sabre versions) had multi-weights in the oil section.

I ran 15W40 for a number of years.... and as many engines do develope an oil leak here and there I switched to 30W then 40W (when I could find it) when I spent longer times in hotter climates. The switch to the single weight was to slow down the leaks mostly because the oil analysis between all the oil weights wound up the same with no recommendation to change.

 

[Jc180]

Have a Perkins 6.354.4 just rolled over 6000 hours (3000 hours by me). Starts immediately and runs smooth. Use Rotella 10w40, Wix oil filter, and 100 hour oil change interval.

 

[catalinajack]

Do wat de book sez.

The book was written 65 years ago. There have been a few improvements made to oil formulations since then. A straight grade oil is inferior to modern multi-grade oils.

 

[catalinajack]

Does the winter weight on a multi-weight oil really matter when its 85 degrees out? I never run the boat below 50 degrees F.

Yes, it does matter cuz the oil reaches the parts to be lubed sooner.