LUBRICANTS. BASIC WHATS AND WHYS.

[Peter.]

This area is one that causes much head scratching amongst many and, to most questions, there is a simple/logical approach. I spent a number of years involved with a large oil company in the testing of lubricants and the analysis of the results. It has also stayed as a personal interest topic long after. This has resulted in access to many of the developments and secrets behind what-why and this -that is recommended. If any of you out there have questions, I am happy to give you guidlines to follow. It is not intended a "This brand is better than that" forum. Just that you can get answers to questions so you can make a decisive decision.

[Peter.]

As a start point, as Castrol once pointed out, Oils aint oils. There are Dino (mineral), synthetic, vegetable and heaps inbetween. So what characterists does each have? Where do they fit into our boating (Yes this a boating forum) world? How do we understand the lable on the can? What makes our filtration system so important? Why did this/that fail?
As these points are raised, answers will appear, that should give an insight as to how the jigsaw goes together. In many cases there will be more that 1 possible answer. No one-answer could be expected to cover all. The intention is to give you information upon which you can make a decision you are content with.

[Peter.]

Question:  LS1. Max RPM 4700. Cruise 2600-3500. Using Semi synthetic 10-40. .
The LS1 engines had a fault at the start of oil consumption. This was a 2 fold problem. Firstly the initial fill was often a full synthetic that was not a good choice as it prolonged bed-in. This was especially true of Australian vehicles.
The second was a design fault in the piston. The skirt was too short and allowed the piston to tip slightly in the bore. This resulted in the rings losing contact with the bore hence oil consumption problems. Many engines siezed as a result. The cure was new design pistons which had a teflon coated skirt, for minimal clearance. Along with slightly different ring design, and mineral oils, stopped the problem. Once run-in, synthetics could be re-used. How many of the origional un-modded ones are still out there is anyones guess.
As to oils, use a semi synthetic with a 15W-50 rating. One well known one comes in a blue container and you may have to ask specially for it.
Why this grade? Keeps its' body better at high temps than 10-40 so a more stabil film where it matters. Also let engine warm up before giving it the message.
As for temp. try to keep to a max of 100 Degrees C. No oil likes to run much hotter than that without rapid degredation (oxidation).
Change at 50hr intervals without fears. Use good filters. Non name-brand are cheap only if engines are cheaper.
A well considered point is that engine designers like to see 10psi/1000rpm.  In this case a top figure of 50+psi would be ideal, However many Americian engines can't reach that figure so 40+ would be fine in this case as racing is not a major consideration.

[mohawk]

The filler cap on my 4.3 vortec says use 10-30 ,but ive been told use atleast a 40grade by most mechanics. i run a 70 deg thermostat with 2 3mm holes and it runs just under 70deg with 55psi......( i intend to go back to deisel oil 15-40).....
 
Am i corect to assume raw water coold engines run at 70 in salt water ,and if so does this shorten the life span of the engine a great deal?

[Peter.]

Use a multi-grade in all but extreem engines. Poor cold-start lubrication can result from a mono-grade. Your oil cap rating is for the USA market regarding fuel efficency. Use a 10-40 without fear, or a diesel grade. Stick to a CH-4 Diesel or SL Spark Ign rating. Get the temp up to 80-85 deg C. 70 is way too low. Use a proper heat exchanger and a thermostat in the engine. You will have fuel settle-out on cyl walls resulting in wear and oil dilution. Keep oil temp 80-100 Deg C. Change as you see fit up to 100hr intervals. Use name-brand filters for oil and air. Check your oil pressure after normalising . Around 10psi/1000rpm is great.

[Peter.]

How to read an oil pack.
On the lable there are a number of important points as to what you are getting-well supposed to be...
The first is an API rating of SH, SG Etc. These 2 letters preceeded by the S are ratings for spark ign engines. They relate to the era of engine the formulation applies to.Diesels use CG, CH.CH-4 etc. C=compression ign. Many now have dual ratings but a dedicated Diesel lube is the preferred in that application as the additive package is more suited. But use a Diesel oil in a petrol if you wish providing the viscosity is correct. Helps to keep it really clean inside. That's as clear as mud isn't it? Better explain beiefly.
As manufacturers go along, technology changes, as do operating conditions. The lubricants are required to change too so as to better cope. These letters follow the formulation progression. Use the highest you can is the rule. However some of the Thicker oils have older ratings as they are seldom used in late applications. Is this a problem? Can do in late high performance multi-cam turbo applications. Ask first!! .
The next, and probably, most questioned part are the SAE figures. IE 10W-40. What does this really mean? I shall explain.
There are mono-grade and multigrade oils available. At this stage disregard mono-grades as their usage is limited and those who use them are well aware of their uses and limitations.
Back to our 10W-40.

The 10W figure applies to the thickness of the oil at 0 dec C This is approx equal to a mono 10 grade.
The 40 part is what the lubricant is equal to at 100 deg C. This is achieved by the addition of viscosity improvers added to a 10 weight base oil. So it thins out at a lessor rate than a straight 10. Gives good cold start and still provides safe protection at  operating temp. Got that?
Now  the additive package used has a problem in that, as time progresses, it shears (breaks down). The rating drops to 10-35, 10-30 etc as time progresses. This is a phenomenin that happens to all oils. Nothing to get too concerned about if regular servicing takes place and excessive temperatures, in the sump, are not occurring.
A point to note about mineral oils (Dino type) is that the difference between the back and front numbers should not exceed 30 (Spot on for 10-40 & 20-50) This is because the additive pack is not good at holding a greater range for very long. So we go to Semi-synthetics.
Here the Dino is mixed with one of the synthetics and a wider range is possible alog with a much greater stability in viscosity. 15W50, 10W-60 etc.
These lubricants offer a great value for money and are all that most operators will ever require. Note that I have not said "Synthetic Fortified" This description means diddly squat. If the seller is asking a premium for this feature, just give it a miss as you may as well stick to the basics.
Many Semis are 50-50 mixes and give good performance without the cost of full synthetics. Next will cover synthetics and the basic differences between the bases used.

[Peter.]

Question: Lack of cooling air around sump of boat engine. Can this be detrimental?
Sure can. As the oil is used as a major cooler of engine internals it gets hot in return. The air flow in a car removes that heat from the oil but in a boat there is limited air access.
Lubricant temperatures should not exceed 100 deg C as the rate of break-down and oxidation increases rapidly. IE the oil starts to lose its ability to do all the good stuff.
Put in a temp guage and a cooler if required. However DO NOT OVERCOOL the oil or the buildup of fuel residue and moisture, can dilute it quite fast. 80-100 is ideal. Synthetics can go way past this but then bearings start to fail.
But run the engine at the usual temps as per car. Around 80-85 deg is perfect. 70 is way too low.
Use a heat exchanger with antifreeze coolant at 50-50 mix. Cuts out corrosion, boiling, localised hot-spots etc.

[Peter.]

Finally, in the general coverage of lubricants, I shall give a brief overview of synthetics. There is no need to confuse this issue, as it is too complex for this site, or for that fact most sites.
They consist of one of two bases Poly Alfa Olefin (PAO) (Cheapest) or Ester (Expensive). Their main points are stability in extreem operating conditions and are a natural detergent. They are compatable with mineral oils so if mixed do not "fight" with each other. The incompatability that caused seal leakage in the past, has been addressed. They are expensive, do a top job in extreem conditions and, if you feel the extra cost is justified, use them. They still require changing and are not a cure-all for mechanical defects.
In high cost machinery they are cost effective, however the average application such as we put them to, it is a luxory item rather than necessity.
The lack of waxy content makes them very stabil as to viscosity and easy flow very low temps. Heat has less effect too but that is not to say that this area be explored.
So that gives a brief overview of what oil is & does. The modern cars are usually recommended to use 10-30 or similiar grades. This for fuel economy purposes as the power required to pump the oil around is less as well as the drag through bearing surfaces is less. The power to drive the pump is considerable so lees here means better economy.
In marine applications of sustained high speed and temperature, these oils are really too light.  We require a heavier-bodied lubricant but care should be taken to chose one that is not too heavy or poor cold performance could cause major failures through wear/siezure.
(If one looks at this field closely, you will see some very wide viscosities advertised. The widest that is commonly available is 5W-60. This is an ideal range in that it is thin for cold start and gives top protection at higher temps. It is also an indication as to what a labroratory can achieve over nature.)
Let an engine warm up, or even better, pre-heat before.
Oil is the lifeblood of all moving parts. A good quality lubricant is still cheaper than the cheapest engine-though some will challenge that statement.

[Peter.]

It was only a matter of time before the question of additives cropped up.
Firstly, these products are not as secret squirrel as would be expected. The oil bods know all about them and opinions are as varied as there are potions.
Secondly that industry is huge so all sorts of hocus pocus advertising goes on.
As to using these, there is a risk that they can counteract the package already in the lubricant. Mostly they are a total waste of consumer dollars.
It is suggested that where a semi or full synthetic lubricant is used, NO additives be added. As for the good old Dino types, If you feel it helps, well do so.
If adding a "Stop Smoke" type product, bear in mind that, as these "thicken" oils, there is a possibility of ring lube starvation on good engines. This is not good.
For a bottom line suggestion: save your dollars for fuel.

[Peter.]

The last major topic, I guess in this column, is fitration. Having good lubrication is one thing-good filtration is another.
Oil filters have a big job to do in keeping the nasties at bay. Always use a brand name one. That may sound stupid but there are a number of sub-standard units coming available out there. The big difference is the quality of the filtering meduim- the stuff that does the work.
If you open up a number of different brands, you will see a big difference in what manufacturers consider sufficent filtering material. Some Asian unknowns have little more than a layer of "Dunny paper" whereas the "Good ones" have the right stuff. Use commonsense here as the durability of your engine can be goverened, quite severly, by this.  Actually it is good practice to cut open the filter every time you do a change, just as racers do, and just see what has been caught. Might prevent a major disaster by letting you see what is not well before the whole engine self destructs.
Air filters are very important too. You might consider the river/lake area clean but the amount of wind-blown sand might just suprise you. They also can act as a flame stop in the event of a back-fire.
In this area, the choice is huge from a mesh grill (Absolutely useless) to state of the art oiled cotton types. If you are familiar with K&N or Green Cotton brand filters, you will also be aware of the cheap imitations that the boy racers use. They are heaps cheaper but have a poor filtering factor. If you have a good engine, dont skimp in air filters either. Most paper types are quite suitable- again stick to name brands.
Poor filters let thru heaps of grit which acts like sandpaper slowly grinding your pride & joy to bits.
Again it's your choice. Are engines cheapr than filters? There are grave doubts about this.

[Peter.]

Any so the questions keep coming. Thanks for the comments. By asking questions it makes it easier to give specific replies.
Should I put an engine flush in my motor before draining the oil? Personally I say no. Why is that?
If an engine is well maintained, the build-ups should never get to the point where a special flush is required. There is a risk that the flush will loosen buildups of nasties which could lead to pick-up screen blockage and resulting decrease in lubricant access to the pump-and so on. It has happened!!!

Is there an Air filter which has approval as a flame trap?  Yes. K&N is approved by the US Coast Guard as such. There are probably others too.
A flame trap is a necessary item on a spark reliant engine in any boat. IE Perol, LPG. Might just prevent you having an unwanted burn at the most inopportunate time..

[Peter.]

I have had many questions asked and I have answered directly as they are very specific where a general answer would not have sufficed. I am now opening the topic to the masses as there must be many too afraid to ask. Go for it. I will not rubbish any genuine points. All I ask, and so do the sponsors,is that they are genuine. If it is an important topic please ask as most sites do not give  the opportunity to ask and get a genuine reply.
I can also answer many engine specific points too. I can assure this is an international site as PM's have confirmed. We are not alone. --!
If you don't ask well............

[wildrj]

http://www.knfilters.com/marine/boats.htm

Found this-
P/N 59 3264 suit TBI and 4bbl just under $100us from Jegs.

I'll be ordering a couple ASAP.

[Peter.]

 

[wildrj]

RE; K&N Filter, P/N 59 3264
This part was not easy to get.
Doesn't seem like any-one in Oz carries them.
Finally ordered one through Amazon.com, via a crowd called "the Fulfillment Centre" (sounds like a dodgey cult!).
Cost- $172.50Aust.
Its the ONLY device I could find after quite a bit of trawling that was a Coast Guard approved spark arrestor AND air filter for a 4bbl carb.