Oil weight for older diesels?

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sunchaser said:
Robert Durio said:
You will find that where lubrication is critical, synthetic is the only oil used.

QUOTE]

Nice advertisement.

Here is a simple question Robert, why does Cat not recommend a longer oil drain time for synthetics vs Dino in their off road equipment warranty programs? In fairness, Cat does suggest, but not insist on synthetics for Arctic work.
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I don't know.

I do know, however, that since all the molecular chains are relatively consistent in length, (instead of a mix of longies and shorties), so there are no longies to break down, hence the more durable nature of the oil.

If you are attempting to argue that synthetics are NOT vastly superior, you are fighting an unwinnable fight. The only time I would avoid synthetics are

a) at breakin (the are so good at protecting from metal-on-metal wear, they prevent proper break-in.

b) if you have roller-lifters (not enough friction to roll the roller).


c) It is somebody else's engine, and your oil -
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How about "semi synthetics"? What does that actually mean, and are they worth using?
 
I love these oil threads, they drive everyone crazy.

Lehmans smoke, they all do. One of the big reasons you don't see them in modern cars. However, they always start, sip the fuel and can be field-stripped with a crescent wrench and a Harley tool (large hammer). Don't neglect the Simms pump, never pull the drain plug until the filler plug is out (don't undo the level plug at all, measure the oil) and never try to warm it up by idling. The sooner you leave the dock the faster it warms up and the farther you will be from the pitchfork and torch crowd.
 
Xsbank said:
I love these oil threads, they drive everyone crazy.

Lehmans smoke, they all do. One of the big reasons you don't see them in modern cars. However, they always start, sip the fuel and can be field-stripped with a crescent wrench and a Harley tool (large hammer). Don't neglect the Simms pump, never pull the drain plug until the filler plug is out (don't undo the level plug at all, measure the oil) and never try to warm it up by idling. The sooner you leave the dock the faster it warms up and the farther you will be from the pitchfork and torch crowd.
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You have mentioned this at least once before...resoning for all?
 
BruceK said:
How about "semi synthetics"? What does that actually mean, and are they worth using?
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Conventional/Synthetic Blends. A halfway measure, I think, but perhaps an on-ramp to the good stuff.

BTW, Synthetics are good for more than just for the crankcase, turbine oil tank etc., they are also great for gearboxes, and grease for roller/ball bearings (don't get me started on the vast superiority of ceramic bearings vs steel bearings).
 
I don't know about you but I don't read everything. It sounds like there is a new owner on here and he has a smoking issue which concerns him. An overfilled Simms will cause problems and most new engine owners don't expect to have to service the pumps every 50 hours. If I am being tedious I apologize, would you like me to delete this post?

I'm not even sure he has a Simms pump.
 
Robert Durio said:
Conventional/Synthetic Blends. A halfway measure, I think, but perhaps an on-ramp to the good stuff.

BTW, Synthetics are good for more than just for the crankcase, turbine oil tank etc., they are also great for gearboxes, and grease for roller/ball bearings (don't get me started on the vast superiority of ceramic bearings vs steel bearings).
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Most agree gearboxes are where synthetics shine..but at the rate of necessary change for combustion products in engines...are really a "waste" or overkill for an engine in moderate to light service.

Not all my words but of many very reputable mechanics and engineers.

So far, dino oils have shown to be able to make an engine last till it's reasonable rebuild time...synthetics haven't without a doubt been proven to extend that life...otherwise we would hear a lot more of "synthetic only" chatter..
 
psneeld said:
Most agree gearboxes are where synthetics shine..but at the rate of necessary change for combustion products in engines...are really a "waste" or overkill for an engine in moderate to light service.

Not all my words but of many very reputable mechanics and engineers.

So far, dino oils have shown to be able to make an engine last till it's reasonable rebuild time...synthetics haven't without a doubt been proven to extend that life...otherwise we would hear a lot more of "synthetic only" chatter..
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In an engine of moderate or "light" service, I would agree - overkill.

But if you want an engine to last and last, to prevent ovaling of bores and low Oil Pressure from worn bearings, and all the other effects of engine wear, synthetics will get you a lot farther.

So far, synthetics allow Formula 1 engines to run at a 19,000 rpm redline (compared to 7,500 for a J79 in a F4 Phantom at Mach 2).

Nobody puts conventional oil in aviation engines - they cost to much to use "dino" oil, too much is at stake for "dino" oil.

Perhaps they are too good for the folks that make a living dealing with the failures of "dino" oil to chatter about them.

I can hear it now ""Hush" about synthectics. I earn a nice living re-sleeving, reboring, re-bearing ing, re-valving !!!!"
 
Durio says "You will find that where lubrication is critical, synthetic is the only oil used."

Of course. But engine lubrication on the average and for that matter most all trawlers do not have critical lubrication issues. Definitely about the least critical lubrication needs for most any engine. Warm up slow, low pressures, low forces and low heat. Smashed up bananas may even work. But I will admit the above quote is correct. When I ran 2 stroke engines at WOT for 5 min to 20 or so minutes with lean mixtures and cylinder head temperatures over 400 degrees I used a racing highly viscous full synthetic "oil". Lube issues were indeed critical and syn was the best and close to necessary. But our trawler engines have very un-critical lubrication requirements.

I even agree w psneeld.
 
manyboats said:
Durio says "You will find that where lubrication is critical, synthetic is the only oil used."

Of course. But engine lubrication on the average and for that matter most all trawlers do not have critical lubrication issues. Definitely about the least critical lubrication needs for most any engine. Warm up slow, low pressures, low forces and low heat. Smashed up bananas may even work. But I will admit the above quote is correct. When I ran 2 stroke engines at WOT for 5 min to 20 or so minutes with lean mixtures and cylinder head temperatures over 400 degrees I used a racing highly viscous full synthetic "oil". Lube issues were indeed critical and syn was the best and close to necessary. But our trawler engines have very un-critical lubrication requirements.

I even agree w psneeld.
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Just for the record, I am not saying Synthetics are necessary for Trawlers, per se, just that they are vastly superior to conventional oil. Your application may or may not be able to take advantage of those strengths.

I wonder, if the piston side-forces that cause ovaling are greater at high rpm or low. If you are "lugging" the engine, it may be considerable harder on the bores than higher rpm settings.

Anyone have any info on that issue.

I would also assert, that if you are trying to get the most total running time out of an engine, use synthetics absolutely.
 
Robert Durio said:
So far, synthetics allow Formula 1 engines to run at a 19,000 rpm redline (compared to 7,500 for a J79 in a F4 Phantom at Mach 2).

Nobody puts conventional oil in aviation engines - they cost to much to use "dino" oil, too much is at stake for "dino" oil.
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Sorry Charlie ... you couldn't have picked two applications that have less to do with each other and require properties at near polar opposites.

F1 engine might turn 18 or 19krpm but not for long enough to last the typical taxi time an aircraft sees in a day. That herring is really really red.

Gas turbine lube oil is not exposed to products of combustion, it doesn't need the same additive "package." Aviation turbine lube oil requires a high resistance to oxidation at temperatures a diesel engine never sees, it requires a viscosity index across a range of temperatures a diesel will never see. Synthetics provide those properties, and have since the 1950s.

There is more to an oil than the rpm of the parts it lubes.

Reciprocating aircraft engines happily use "dino" oil, most do. When you change oil at 25 or 50 hours it is an expensive and pointless exercise to use synthetics unless you operate in some extreme condition. As long as we are talking about recips, another reason not to try to compare the applications (for reasons I would probably get into trouble for positing here) is that a diesel requires a very specific additive package with compounds not used in aircraft lubricating oil since the 1950s.

I may be as thick as cold dino oil but I seem to have missed the point ... what was it again?
 
Robert Durio said:
In an engine of moderate or "light" service, I would agree - overkill.

But if you want an engine to last and last, to prevent ovaling of bores and low Oil Pressure from worn bearings, and all the other effects of engine wear, synthetics will get you a lot farther.

So far, synthetics allow Formula 1 engines to run at a 19,000 rpm redline (compared to 7,500 for a J79 in a F4 Phantom at Mach 2).

Nobody puts conventional oil in aviation engines - they cost to much to use "dino" oil, too much is at stake for "dino" oil.

Perhaps they are too good for the folks that make a living dealing with the failures of "dino" oil to chatter about them.

I can hear it now ""Hush" about synthectics. I earn a nice living re-sleeving, reboring, re-bearing ing, re-valving !!!!"
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Have one piece of scientific evidence or industry standard publication that supports this?

Nothing from an oil/lubricant industry is acceptable.....
 
Nothing from an oil/lubricant industry is acceptable.....

One big USER of syn oil seem to be the trucking industry , but they cheat and use secondary oil filtration , big filters or a spinning cleaner , and they Only change oil as required by extensive oil testing.

For them it saves money , for a 30-40 year old underloaded farm implement marinization , fresh dino would do far better.
 
On new and commonly used marine diesel engines we may normally run across, the only one my faulty memory recalls that mandates/requires synthetic is MAN. Are there any others that require synthetics and not Dino by the book - to keep warranty in place?
 
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Robert says; This is due to a more consistent length of each oil molecule, which can be thought of (analogized) as little pieces of yarn. In conventional, some are very short and others are very long, i.e. inconsistent. In Synthetic oil all the molecules are very close to each other in length.

What I read and was told is synthetic oil's molecule is like a magnet on one end and sticks to the metal parts of the engine. It doesn't roll off. Conventional oil does that.

This is why engines wear with conventional oil. Startup is when metal to metal wear occurs. Look at the old advertisements for slick 50 all the oil is gone at startup.

<iframe width="640" height="390" src="//www.youtube.com/embed/WGvDqxG7dcU" frameborder="0" allowfullscreen></iframe>

I couldn't find that ad but I think most will remember it.
 
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Now if Robert only had some remedies for the real maintenance issues that plague us ----------------
 
RickB said:
Sorry Charlie ... you couldn't have picked two applications that have less to do with each other and require properties at near polar opposites.

F1 engine might turn 18 or 19krpm but not for long enough to last the typical taxi time an aircraft sees in a day. That herring is really really red.

Gas turbine lube oil is not exposed to products of combustion, it doesn't need the same additive "package." Aviation turbine lube oil requires a high resistance to oxidation at temperatures a diesel engine never sees, it requires a viscosity index across a range of temperatures a diesel will never see. Synthetics provide those properties, and have since the 1950s.

There is more to an oil than the rpm of the parts it lubes.

Reciprocating aircraft engines happily use "dino" oil, most do. When you change oil at 25 or 50 hours it is an expensive and pointless exercise to use synthetics unless you operate in some extreme condition. As long as we are talking about recips, another reason not to try to compare the applications (for reasons I would probably get into trouble for positing here) is that a diesel requires a very specific additive package with compounds not used in aircraft lubricating oil since the 1950s.

I may be as thick as cold dino oil but I seem to have missed the point ... what was it again?
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Obviously, but I'll happily put you back on track.

My point is that synthetic oil is vastly superior to conventional oil in both lubricating and heat removal. Clearly, from my examples, it is not a one-size fits all proposition as your Red Herring attempts to make it out to be. The oil used in an gearbox, isn't the same as the oil in a turbine engine or in an aircraft piston engine, or a high-rev racing oi, or heavy duty engines, but in all cases, a synthetic product will outperform a conventional one, both intended for that application.

My point is that synthetics are superior to their conventional counterparts, and your response is that conventional oils are good enough. In some cases, 3 in 1 Oil may be good enough, but that isn't my point, which boils down to "better", not "good-enough". You are debating a different debate. I believe that tacticis called a "Strawman"

And, and I know this is off topic, all-ceramic ball bearings are vastly superior to steel ones, and in a marine environment, their resistance to corrosion may, all by itself, justify the add'l cost, but that is a gauntlet for a different thread.
 
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:pirate: I'm a single malt guy, thank you very much. :)
 
One can't escape the fact that dino oil protects and lubricates engines to over 20,000hrs w/o synthetic lubricants. One must conclude from that that there is not a significant benefit from using synthetic lubricants. Just a waste of money.

Durio how can syn oil be "superior" if dino oil is "good enough"?

As to the ovaling of cylinder bores I think it can only be done by sideways forces created by the downward force of combustion and the angle of the connecting rod. So it appears to me that load has a much greater effect on ovaling than engine speed. People have the misguided notion that noise = wear and more noise = more wear. Much to most of the time w most diesel engines noise may be our friend.

Assuming that this is true it seems an engine turning higher rpm w less load would experience considerably less wear than an engine that has a higher load such as one that is coupled to an over pitched propeller. So it looks like an over propped boat pushing a boat at the same speed as an under propped boat would result in higher wear and less noise for the overpropped engine and more noise and less wear for the underpropped engine.

Ring wear may be relatively unaffected by the side loads caused by combustion forces and the connecting rod together but combustion forces alone will cause more wear with certain types of rings that are pushed against the cyl bore by combustion forces. So the overpropped engine may suffer more ring wear as well.
 
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Robert Durio said:
My point is that synthetics are superior to their conventional counterparts, and your response is that conventional oils are good enough.
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Synthetic lubes are superbly suited for some applications. Mineral lubes are superbly suited in other applications. Sometime those applications overlap, sometimes they are mutually exclusive.

Most people who are involved in operating and maintaining expensive machinery know which lubricants are suited for what and happily use whichever is best for the application.

People who don't really know or understand that most of the world exists between the poles tend to make silly statements.
 
manyboats said:
One can't escape the fact that dino oil protects and lubricates engines to over 20,000hrs w/o synthetic lubricants. One must conclude from that that there is not a significant benefit from using synthetic lubricants. Just a waste of money.

Durio how can syn oil be "superior" if dino oil is "good enough"?.
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Unless, or course, you want or need an oil that will protect and lubricate that same engine for over 40,000 hrs:rolleyes::rolleyes:.

"Superior" is a Objective term that can be determined by discreet, definable and testable parameters.

"Good enough" is a subjective terms

Apples and Oranges, my friend,
 
Robert Durio said:
Unless, or course, you want or need an oil that will protect and lubricate that same engine for over 40,000 hrs:rolleyes::rolleyes:.

"Superior" is a Objective term that can be determined by discreet, definable and testable parameters.

"Good enough" is a subjective terms

Apples and Oranges, my friend,
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Can you produce ONE bit of evidence that synthetics will cause an engine to last 2X as long.?

People have been trying to for years and haven't been able to...love to see if you know of one.
 
RickB said:
Synthetic lubes are superbly suited for some applications. Mineral lubes are superbly suited in other applications. Sometime those applications overlap, sometimes they are mutually exclusive.

Most people who are involved in operating and maintaining expensive machinery know which lubricants are suited for what and happily use whichever is best for the application.

People who don't really know or understand that most of the world exists between the poles tend to make silly statements.
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Can you think of a single application where a conventional oil is superior to its synthetic counterpart. And please, the question is "superior", not "cost effective".

I have found two, so far

1. Breaking In - Synthetics are just too effective to allow parts to break-in against each other.

2. Roller-lifters - Not enough friction between lobe and lifter to roll roller.
 
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psneeld said:
Can you produce ONE bit of evidence that synthetics will cause an engine to last 2X as long.?

People have been trying to for years and haven't been able to...love to see if you know of one.
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In the aviation industry, synthetic lube have allowed old radial engines to last for decades - DC3-s still fly profitably pulled along by ancient engines protected by synthetic oil.

It is sad, but not unexpected, to see such resentment for and animus against, the "new-fangled" stuff. Luddites even poo-poo'd the automobile
 
Cylinder oil.

There are more than I have patience to play your game with. Have a nice day.
 
Robert Durio said:
Can you think of a single application where a conventional oil is superior to its synthetic counterpart. And please, the question is "superior", not "cost effective".

.
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Yes, dozens if not hundreds of real world applications come to mind where synthetic is not superior.

Highway or off- highway internal combustion engines for cars, trucks and big iron, when new, offer a warranty. In most cases (exotic cars excepted) this warranty stipulates oil change intervals that are identical for synthetics and dinos. The warranty is voided if the hours recommended are exceeded. I have direct knowledge of big iron multi million dollar per year warranty programs that so state.

A 4000 HP haul truck truck engine is pulled after about 18,000 hours and rebuilt to last another 18,000 hours on a rigorous warranty and PM program. I know for a fact if synthetics would provide a 25% greater margin the users and manufacturers would indeed embrace it. It is not only about oil, it is about all the other things that create havoc for an IC engine that the builders and users are on the lookout for.

Preach as you might, the IC world is well beyond the nonsense that synthetic is a magic elixir for what ails us.


The bottom line for years regarding synthetics has been:
  • Good - yes,
  • sometimes better - maybe,
  • always better - no.
Please, the question is always cost effective, not superior - always. And cost effective takes way more into account than the base price per gallon of oil vs synthetic, way more.

I trust you have some credentials?
 
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sunchaser said:
Yes, dozens if not hundreds of real world applications come to mind where synthetic is not superior.

Highway or off- highway internal combustion engines for cars, trucks and big iron, when new, offer a warranty. In most cases (exotic cars excepted) this warranty stipulates oil change intervals that are identical for synthetics and dinos. The warranty is voided if the hours recommended are exceeded. I have direct knowledge of big iron multi million dollar per year warranty programs that so state.

A 4000 HP haul truck truck engine is pulled after about 18,000 hours and rebuilt to last another 18,000 hours on a rigorous warranty and PM program. I know for a fact if synthetics would provide a 25% greater margin the users and manufacturers would indeed embrace it. It is not only about oil, it is about all the other things that create havoc for an IC engine that the builders and users are on the lookout for.

Preach as you might, the IC world is well beyond the nonsense that synthetic is a magic elixir for what ails us.

I see you, in your desperation, have taken to Strawmen ("magic elixir"). When people act so disingenuously, I tend to opt out.




The bottom line for years regarding synthetics has been:
  • Good - yes,
  • sometimes better - maybe,
  • always better - no.
Please, the question is always cost effective, not superior - always. And cost effective takes way more into account than the base price per gallon of oil vs synthetic, way more.

I trust you have some credentials?
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I see you, in your desperation, have taken to Strawmen ("magic elixir"). When people act so disingenuously, I tend to discount them steeply

You may recall, that I said Synthetic Oils are superior (a technical assessment). Failing to offer any but pap to that "question", your pulled up the Cost Effective Strawman, and seem to do so only in the short term, never taking the long term effects into account.

By every measure of what an oil does, (film-strength, coefficient of friction, heat transferal, corrosion inhibition, engine cleanliness, startup protection) synthetcs trump conventional hands down - period. I agree, if you are lubing your favorite pair of tin-snips, probably not going to make much difference, but if you are lubing up something every expensive, and vulnerable to heat and friction, go with the best.

I'm outta here. It is obvious that this forum is full of "dino's" with closed minds. Too busy to deal with chumps, especially antique chumps
 
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Robert Durio said:
I'm outta here. It is obvious that this forum is full of "dino's" with closed minds. Too busy to deal with chumps, especially antique chumps
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You never told us about your trawler. ;)
 
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