Synthetic oil and engine noise?

I was told today that using synthetic oil can reduce engine noise by as much as 25%, has anyone heard of this or had any experience with this?

NO!

Of course, everyone knows this for fact. While you're at it install AlgaeX magnets, a Gulf Coast filter (with*paper towels*of course), Air Seps, Prop Speed, etc etc.

Owww, a little sarcasm from SunChaser. Glad your sense of humor hasn't been dulled by the onset of fall and winter. ;-0

Ken

The value in "synthetic" oil is its lower viscosity.

That means all parts get lubrication quicker on start up., and less energy is used scraping the thin oil off the cylinders, giving perhaps 3 to 5% better fuel economy.

Cost is the downside and unless bypass filtration and the oil change much extended by constant oil analysis , not worth it.

Ob a 24/7 tug , sure , on a 200hr pleasure bucket , no way.

Besides cost another downside is poorer rust resistance during extended out of service times.

Some folks will "cheat" and use a gallon of synthetic with 6 or 7 gal of std oil to get the better sheer of the synthetics.

FF

sunchaser wrote:

Of course, everyone knows this for fact. While you're at it install AlgaeX magnets, a Gulf Coast filter (with*paper towels*of course), Air Seps, Prop Speed, etc etc.

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A mechanic at the very highly respected Zimmermans told a fellow boater at my marina this. I called Brian at American Diesel and he thought this might be true for smaller displacement high HP new engines but wasn't sure about slow turning large displacement Lehman's etc. By the way what is wrong with Prop Speed other then $? What is wrong with Air Seps and the Gulf Coast Filter?

*

"Wrong with" --- nothing, just depends on your POV.**

But since you asked: Prop speed, a diver is much cheaper plus I get the bottom cleaned. Air sep - great for slobbering 2 strokes, dubious on others and definitely not needed on my twin Perkins. Gulf coast filters - I'd rather three stage, 30,10 and 2 micron (on engine) for less money and smaller setup.

Daddyo, Be careful using synthetic oils in some older engines, it can actually do harm to the engines. Chuck

Daddyo wrote:

I was told today that using synthetic oil can reduce engine noise by as much as 25%, has anyone heard of this or had any experience with this?

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*Haven't heard anything*since I put synthetic oil in my ears.

i have to differ with sunchaser a little...
i have an older volvo 70B, no turbo, i have gulfcoast oil/fuel filters. the normal screw on oil filters are usually somewhere in the 25 to 30 micron size! the 30/10/2 refered to are racor fuel filter micron sizes...the fuel filters on my bosch*fuel lift pump, are 5 micron...the gulf coast 'paper towel' filters are abt 1 to 1.5 microns...gulf coast also makes a o1-jr, that uses a roll of terlit paper. i have one on my 92 dodge/cummins. i use scott 1000 terlit paper, change the roll at 3000 miles, send an $8 sample in every other time, and just changed the oil at 20,000 miles...sample sent, oil fine! been playing with these frantz/gulf coast type filters for over 40 yrs, and i think they keep the engine clean much more than the screw on filters, and that extends the life of whatever they`re on! a while ago, before charlie, the person that started the gulf coast filter*company passed away, i was having my monthly fone chat with him, and he told me abt the new*68 cadilac convertable he got for his wife...put his fuel/oil filters on it, and had`nt changed oil yet! that`s over 35yrs! just changed the filter, and added what it needed, and sampled it! oil does`nt wear out, it just gets dirty! as to running a diesel slow, i run mine at 1300 all the time. before i anchor, or tie up, i kick it up to 1500 for 3 or 4 mins to clean it out...i also just had my original bosch air filter bite the dust, and retro-fitted*it with a k&n. breathes much better. k&n makes the filters for airsep!...the main problem with synthetic oil, is the cost. need to run it for 3 or four times as long as we run mineral oil...so we who believe in them, use the bypass oil filters...it isnt rocket science, just takes a little research, and knowledge, and effort!...c*

From what I've heard and read oil DOES wear out. Oil suffers from mechanical, chemical and heat abuse. The reason oil is slipery is that it has long molecules and being subjected to gears and piston shock the molecules get shorter. I think very old oil will become thicker because of this. Salts and other corrosive elements that no filter will remove will cause pitting and corrosion. Filters are there to stop solid potentially abrasive material from doing damage. Iv'e heard about super filters, even toitet paper filters since I was a teenager. Any mainstream engine expert will say "change the oil often" and synthetics are fine but who needs them** ..* only those that subject their engines to extreemly severe pressure and heat like a racing motorcycle can benifit much from synthetics. Our Trawlers don't need synthetics but synthetics are definitely better* ..* except for the cost.
Capn Chuck?* What dammage? I remember sage auto mechanics of the past** .. almost all of them said putting a battery on a concrete floor will ruin it. Baugh.

Eric Henning

nomadwilly wrote:

From what I've heard and read oil DOES wear out. Oil suffers from mechanical, chemical and heat abuse.

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Based on hanging around a lot of engine mechanics and engine overhaulers off and on for some 40 years and listening to their advice and opinions, I would say you are very much correct.* And I've never had a mechanic tell me that fresh oil is bad for an engine.* Even with today's prices, lube oil is still damn near free compared to the cost of repairing, overhauling, or replacing an engine.

I have been advised by friends in the engineeriing department of one of the marine industry's most respected engine and generator manufacturer that I should not use synthetic oil in our old FL120s.* (This same company does approve the use of synthetics for their current products.)

The concern I've heard for the use of sythetics in old-generation engines like our FL120s, which were manufactured in 1972 or 3, is that it can have a detrimental effect on things like seals.* I was told that if we had our engines ccompletely overhauled and all the seals and gaskets replaced with components made of more modern materials, the use of synthetics would be fine.* Also I have read posts on boating forums that the newer generation of synthetics are less detrimental--- or not detrimental at all-- to old-style seals and gaskets.* I don't know if this is actually true or not.

Given the low speed and low loading of the engines in our boat, the advantages of synthetics are probably not any more than the advantages of changing the dinosaur oil as often as we do (every 100 hours although the manual specifies 200).* For a higher speed diesel or an engine working a lot harder than ours do, I would think the advantages of synthetics probably make it worthwhile to use.

*

Marin,
Early (like 15 years ago) synthetics would shrink many seals so quite soon they put an additive in the lubricant (can't call it an oil) that makes seals swell and obviously if they add the right amount* the seals stay their proper size. Synthetics now are 100% safe. I cannot, however, think of any reason not to use synthetics in old engines. That could be a holdover from the days when detergent oils were new and old engines were so sluged up a high detergent oil could remove the sludge and render the engine quite wezzey. I don't think synthetics have any more detergents than dino oil. There are benifits to using synthetics but they are small (for our application) and the benifits from changing dinasouar oil twice as often is much higher.

Eric Henning

"Early (like 15 years ago) synthetics would shrink many seals so quite soon they put an additive in the lubricant (can't call it an oil) that makes seals swell and obviously if they add the right amount the seals stay their proper size. Synthetics now are 100% safe."

What we call "Synthetics" is still plain old oil, its just refined further.

The oil molicules are smaller (so drain better) , but there still colored oil.

FF

"What we call "Synthetics" is still plain old oil, its just refined further."

I don't know who your "we" is but the rest of the world calls them synthetic because the base stock is synthesized. Its molecular structure doesn't exist in nature.

There are "semi-synthetic" oils which use very highly refined compounds to enhance the base stock but synthetic oil uses a man made molecular structure to achieve a desired result. *

Synthetic oil was first used in aviation jet motors by Germany in WW2. The early synthetic from the 60ties and 70ties had a different swell ratio for the seals then the mineral oil, hence some of the early problem. Too fast and the seals are tight, too slow and they leek. Change back to mineral and problems again.
All that is history.
Mineral oil, the result of refining the oil we pump from the ground is a natural product and as such has variations in it's molecular structure according to provenience. Mineral oil is susceptible to heat and above 116C (240F)*it brakes down and oxidises forming varnish and sludge. The natural paraffin contained in oil solidifies at low temperature making circulation at cold start difficult. Yet mineral oil has been used as lubricant for a long time and it does provides adequate lubrication.

Synthetic oil is the result of chemical reactions, synthesis of esters and other nice stuff. Their molecules are smaller and much more resistant to heat and offer a far superior lubrication. They do cost more but they do a much better job for cold startup, no sludge, no varnish, no degradation when hot. On this point you may think my oil never get's 115C (240F) since engine is usually 88C right? Wrong, the oil secondary job besides lubrication is heat extraction from the hottest points, namely the inside of pistons, head and cylinders and it gets very hot there. It cools down in the heat exchanger and in the sump but it gets hit by burst of very high heat that slowly destroy the mineral oil.

Synthetic oil is a superior product and to say it is unnecessary or a luxury in a diesel that may be old and used on weekend is misguided. When the best situation for an engine is working 24/7, the worst is working*a few*hours once a week and if an engine is working in the worst possible situation, synthetic oil may just be what is needed to keep it together.

As for super-filtration with the toilet paper bypass filter, I think that the suppliers of such superior filters would be best served if they stick to what they know, namely filtration. Their products are excellent secondary filters and do extract small particles that harm the engine and that a direct screw on filter can not be made to retain. In order for a direct filtration filter to retain one micron particles it would have to be 20 times bigger to allow the oil to circulate at all temperatures.
Yet the makers of bypass filters insist in bringing up this nonsensical mumbo jumbo of the eternal oil that does never need changing. Clearly a big fat lie that does not serve them. Yet an additional bypass oil filter, providing is not installed to prolong oil change is one way to keep the oil free of harmful solids. Keep your oil always as new...who does not want that?

Can synthetic oil quite down an engine?*
Perhaps the right question is: Would appropriate lubrication quite down an engine? And the answer is of course yes. An engine running on thick oxidised and* contaminated mineral oil will rattle and bang and when oil is replaced, particularly if with the appropriate synthetic oil that is more fluid at start up it will appear that the new oil is the reason for the engine running smoother. Of course good quality new mineral oil may have just about the same effect*

For the rec boat , that may spend months out of service , the poor rust resistance pof "Synthetic" oil will not extend service life.

Unless the engine is sealed , or special preserving oil is installed the cylinders will in time (with any oil) pit and rust.

This leaves more oil in the rust pits the rings cant scrape , leading to more oil use.

Again at 200hrs a year , who cares? , the oil is probably changed before its up in smoke , but for someone looking to take a used boat to Blue Water, , previous service , or the lack of should be a consideration.

FF

FF wrote:

For the rec boat , that may spend months out of service , the poor rust resistance pof "Synthetic" oil will not extend service life.

Unless the engine is sealed , or special preserving oil is installed the cylinders will in time (with any oil) pit and rust.

This leaves more oil in the rust pits the rings cant scrape , leading to more oil use.

Again at 200hrs a year , who cares? , the oil is probably changed before its up in smoke , but for someone looking to take a used boat to Blue Water, , previous service , or the lack of should be a consideration.

FF

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Hi there!
Clearly at 200 hours a year no one is interested in saving a few dollars by extending the oil life. In fact with such low hours it is calendar days and not hours of service that should be counted between oil and filter change.
My point is one entirely different. Synthetic oil is a superior product from all aspects but price. So it is not the oil of choice to save money. It is in the opinion of a vast majority, a superior product more resistant to degradation by overheating and varnish and sludge formation.
However I have to qualify this knowing you have a Detroit 71 series. Those engines are very particular with the oil they use and one sure way to destroy them is by using multi grade oil for example. So there is probably some research needed to find the correct synthetic replacement oil for the straight mineral oil used in the Detroit.

As for low rust resistance? Are you saying that an engine that uses synthetic is more prone to cylinder oxidation? All but strightmineral oils have corosion inhibitors be it mineral or synthetic. If anything one would expect a stright SAE 30 to be more rust prone.
Why do you use quotations around synthetic? Do you think calling an oil synthetic is some form of misnomer? I can assure you it is not. Synthetic oil is not pumped out of the ground, it is man made by synthesising different chemicals.

Kind Regards
Marc

*


-- Edited by Marc1 on Tuesday 6th of October 2009 03:16:48 AM

Are you saying that an engine that uses synthetic is more prone to cylinder oxidation?

Yes , the oils ability to drain rapidly bares the cylinders to the air sooner , so rust is more common.

I don't know where this 200 hours came from but in our case we are talking about 400-600hrs

Well I dont answer for Fred, but at 52 weekends a year if your engine is on for 4 hours every weekend you got 205 hours in a year.

By the way, what engine do you have and how often do you change your oil?

As for synthetic oil, good old wikipedia has some good info.

http://en.wikipedia.org/wiki/Synthetic_oil



-- Edited by Marc1 on Saturday 10th of October 2009 03:04:28 AM

1983 Lehman120, 150-180hrs between changes 400-600 hrs per year.