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TikiHut2

I'm ready too but can't find it near me in a fully synthetic version (just a blended ver). I wonder if other fully synthetic oils in the same viscosity will do just as well as the mercruiser full synth since it seems to be a bit hard to find and top dollar? Maybe Mobile One synth or others?

MarkB

I called mercruiser tech support and they said either the blend or fully synthetic is recommended. They compensate for phosphoric acid which can eat your engine away.

212rowboat

The zinc, I think it is, is good for engines breaking in.. other than that, just change whatever you use on schedule... If you're really concerned with it, use the Blackstone laboratory analysis/report... Ask THEM what to use, and you'll only have to do that if they don't volunteer it..

That merc stuff is made by a smallish outfit in the bayou.. it may in fact be high quality, but I also bet it's high in margin for merc, and recd for that reason above others.

Seriously, guys, if you're that worried, and maybe you should be, use Blackstone. I do on my diesel truck engine, as it would take nearing $20k to replace.

Michael T

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Michael T

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212rowboat

I am sold on syn, too.. and the higher quality the better... I just ain't totally sold on merc oil.. they don't make it, and though it may be a special blend, it still has competitors... So far as the oil itself, the syn is superior.. the true enemy is ash, though, not lubricity, per say- and the detergents in syn are superior to those in dino oils for suspending that stuff.. syn really shows its strength with age compared to dino, and in wider ranges.. the difference, though, isn't so great within the intended life cycle of either..

Dream_Inn

Well, at this point for me the Synth blend is the easiest to get and I change it at least yearly, which is about 60 hours.  Here is an interesting read as well: link 

TikiHut2

DI, interesting forum link and a great read. Those new Mercruiser power plants pictured in that thread are beautiful. 

Gleaned from that discussion and as as Al said it seems that there's a marine oil formulation cert that covers the varying loads on marine engines pointed out by MT. Here's the NMMA link to certified marine oil formulations and Mobile One full synth is missing.

LINK to NMMA listed oils

Time to search for that big red jug and just chock it up to the boat-part-markup madness unless Drew has found a viable alternate.  

DI, Doesn't 60hrs sound a bit long between changes? On the other hand that's only about 4000mi at hwy speed on my boat mule of a truck engine which I'd consider about equally abusive when towing the boat. One of those used oil reports would be interesting comparing the previously mentioned 20hr change and a 60hr.

Learned a lot in this thread. Thanks

212rowboat

outdated to be sure (oils continue to develop), yet this is still a good article and on point with this discussion: duke of oil... also, this is a lengthy read: here.. ... This, also, is a great resource...

and only because I don't expect anyone to read the reasons why I feel this is as important as it is in my terrible way of attempting communication, I just invite you to go to their website and poke around: blackstone-labs..

(looks like I got something to say about it anyway, apologies in advance)- that oil analysis is hugely important if you intend on getting every second of healthy life out of your engine that you can.. the makers of your engine may determine that 'this or that' oil is best suited because of 'x', but they can't possibly know how you use your engine most often, what the specific environment is like, or what other things are going on internally with your engine after you've had it for a while.. that analysis will break it down line by line and tell you what issues you're having, and what you should do about it.. it may determine that there are traces of piston grade aluminum, and coupled with iron from camshafts, or chromium from rings, but lacking lead (bearings), that your oil is not suiting your purpose and coating/adhering as intended- they may ask you about your flow (pumps, obstructions, restriction) and/or suggest you select an oil with higher zinc and phosphorus content, to better protect those parts.. they may peg the presence of exhaust residuals at an excessive level, along with chromium, and tell you to get a compression check because it seems excessive blow by is occurring which is wearing your rings to poo and likely creating opportunity to predet and/or excessive a/f ratio which cuts into economy.. they may find excessive fuel, water, salt, coupled with copper or bronze- indicating gasket issues at the heads or intake manifold or a bleeding freeze plug you can't readily see.. you can then head catastrophe off at the pass..

point is-> get the analysis... $25 well spent.. let the independent analysis determine what kind of oil you run, and for how long you should run it between swaps.. you may find that your engine is better suited to lighter oil (more readily absorbs heat, actually prolongs reaching operating temperature) or heavier oil (doesn't absorb heat as readily, allows reaching operating temperature quicker) <- that seems counter intuitive, but it is so.. do you make quick runs? or do you hold cruise speeds for prolonged periods? the analysis and following the results will tell you what will serve you best.  

Madcow

I put Amsoil in my sleds and love it, I have heard others say they are running Amsoil marine and love it.

Comments from the peanut gallery?

212rowboat

Amsoil vtech racing oil in 20w50 is what you'll find in my floater in a couple weeks.... I'm selecting that one for the high zinc, and phosphorus, and ability to cling to parts while she sits still for long periods... It's made for high revving engines and hopefully will make my wee wittle 4.3 happy. :-)

mvn

10W-30 (WCT) or 10W-40(WCF) seems to be an option as well according to Amsoil.  See the attached spec sheet.

 

Mark

212rowboat

I misspoke and said v-tech.. it's -Amsoil Z-rod-, not v-tech.. the cocktail is similar to Marine w/ added rust inhibitors, and tons of zinc/phosphorus.. yada blah blah, right? here is a link to it..  that will state my case better than I could.. If I don't choose this one, it will be either the -Marine specific 10w40- or the -Dominator series in 15w50-.. any of these three Amsoil products are a very good choice..

for more readily available oil's if the merc isn't avail, I would be looking to grab up:
-Valvoline 4T motorcycle oil, full syn, in 20w50 ...don't laugh just yet... check it out first... those same compounds that allow the oil to cling to wet clutches will adhere to your hard parts and protect them while the engines sit; and it's not dissimilar to some marine compounds in that regard.. also of note, it is designed for extremely high revving engines and has a metric ton of shear strength- again, similar to the designed use of Marine engines...

-good ol' Mobile1 ... I'd be watching this one close, though.

understand that my purposes are going to be different than y'alls.. I change oil at least twice a year (unless I go with the Amsoil, which will reduce it to once), and I am quick to send out for analysis, I am anal about checklists before every run which includes visual of oil, and my rig doesn't sit in the water unless I'm using it.. If any of those were different, I'd likely either go directly to the Amsoil and stay, or the Merc Syn and stay (at least to the first analysis, that is)..

give me a few weeks, and you'll also find this on my rig instead of a drain plug-



why? So I can run a tube through the plug hole and attach it to the nipple (some models of the valve have a nipple a hose can attach to).. it makes swapping oil hella easier.. the hose can actually be left attached if you coil it up and leave it in the bilge secured with a wire tie...beware, though, if you choose this route: you'll still want to check the magnet from time to time.

Black_Diamond

My 342 has drain hoses for the oil from the factory. You'd have to pull the engines if you wanted to mess with the drain plug. Magnets are most effective in an oil flow galley, not the bottom of the pan. With SS and AL engine parts they are no good anyways.

Michael T

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212rowboat

I yank my boat after every use- and trailer it back up the street a 1/4 mile to the house, and wash the salt off and out of it, along with a visual inspection of all exterior vitals.... it would be hella easier for me to pull an engine and rebuild it over the off-season than it would for most of y'all with your floating RV's.. :-) ... but IF I had a rig like most of y'all, one thing I would add to the instruments is a oil temperature gauge- not just a pressure.. the deltas between coolant/engine temperature and oil would tell you what you needed to know about what is happening in that thing while WOT or even cruising on plane for extended periods... if it was too high oil:coolant, I'd consider a heavier oil (if my use was long range cruising), or lighter (if I was into shortish runs), if that didn't solve it- I'd look for a higher volume water pump- or as a later resort, a higher volume (not higher pressure, that will come all on it's own) :-) oil pump.. if the engine temperature was greater than the oil, I'd select an oil that performs it's duties best at that operating temperature, so you know you're not peeling hard parts..

in a perfect world, you would have a 0* delta between oil and engine temperature- meaning, the oil is not exceeding it's capacity to cool (and is in it's intended lubricity window), and the cooling system isn't creating a huge differential (delta) in temperatures across the block.. the oil is maintaining it's temperature as the environment inside the engine is consistent..  it's working in harmony, like a good build should, if you can manage that..

you can get the analysis I keep harping on, and figure out what oil is best for your purposes- and document the deltas, if you have a gauge... then, while underway, you can keep an eye on that gauge from time to time and be aware when something is happening inside your engine when the delta grows..

if I had the $$$ invested in my rig like you guys do yours, there isn't any way I would run them any extended periods without knowing these things... if you saw a huge spike, you could back down and determine why before hand (or maybe even divert an issue by simply spotting it's product), whereas if you didn't monitor such you could be either stranded awaiting a tow, or pulling engines for catastrophic damages.

sorry for the novel... engine oil is a passionate discussion for me, as well as engines and drive trains..  I'm behind the power curve on marine engines, but fully intend on catching up!! :-) .. synthetic is a no brainer- but if you can't get it for some reason, don't think you're ruining your engines by running dino- it is good, just not as good.

mvn

I hope I'm not hijacking this thread but I'll ask anyway....

On the back of my 5.0L Merc, I've got a hose clipped to the electrical harness near the back of the port side exhaust manifold.  It's an oil drain line with the pipe plug in the end of it.  I think it's supposed to attach to the bilge drain plug and I think it's supposed to be pulled out to the exterior when draining the oil pan.  The only problem is that the depth sounder thru-hull transducer is in the way and there isn't enough room to fish the hose out through the drain plug flange.

On my last oil change, I inserted the oil extractor tube into this hose and was able to get more oil out than by inserting the oil extractor hose into the dipstick tube.  Would it make more sense to get a 12 vdc pump and permanently mount it and attached the oil drain hose to it (through a valve first)?

Would I be able to extract the most oil this way?

Mark

Black_Diamond

The issue with the pump will be if it marine rated (non-explosion)..I bet not.

mvn

I would definitely use a marine pump.   I found several online. 

Mark

seguir

I found with the marine pump, I was only able to extract 3.5 liters out, and left .75 liters in the pan.   When I take it out of the water in the fall I will use oil drain line via the bilge drain plug to get most of it out for a fresh oil change.

mvn

That's what I would prefer to do but the transducer is in the way of the drain hole. 

Mark

TikiHut2

Since I can't find/buy either the Mercruiser full syn or the Amsoil Marine syn on the shelf anywhere near me I'm going to order the 10-40wt Amsoil Marine syn on-line and just have it delivered.

Amsoil Marine Syn LINK

A case(12qts) price seems prudent at only $8.87qt delivered to my door. Now the question is how many qts will I safely expect to use with a filter swap per oil change in my '04 5.7 300hp Merc I/O. I'd sure hope for two changes with a case but wouldn't want to come up short.

Input? Thanks, Mike

212rowboat

short answer: replace the volume you drain..... check your stick, and add as needed..

long answer: you don't, under any circumstances, want to overfill a crankcase.. B. A. D. news... when oil gets slapped about by the crank because it is overfilled, even if the crank is wrapped, it can and will infiltrate into the lobes and get frothed... frothed oil compresses, and that means loss of pressure... frothed oil also expands the volume, which means you have more air in it than oil, and air doesn't lubricate worth a hoot..

TikiHut2

Uh yeah, thanks for the overfill input. These mercruisers certainly knock/etc if overfilled.

Rather than drain the oil to measure how much I'd need to get close on a case order I'd hoped for someone here who could recall their last change volume in a Merc 5.7 V-8....

Found this chart but at on 4.5 qts it seems low to me.  LINK to engine oil change volume

212rowboat

that's about right... 5qts is the capacity of most s/b v8's.. the issue is 'how much are you gonna get out'... I don't mean to sound condescending, please don't take it that way.. it's just really easy to overfill an engine even after you think you're doing it right.. I learned that the hard way once by only overfilling about a quart- and collapsed several lifters due to that nice froth.

TikiHut2

Thanks Drew I'll just order a case of your fav blend and give it a try. Sounds like 6 per change would be more than needed so I'll just have a few extras. Engines certainly have varying volumes usually based on load and it'd seem that a marine engine would be on the higher end but apparently not.

Absolutely no problem, didn't take the over-fill input wrong, and it's sound input for those who haven't been there (and a good reminder too). I was just aiming for another target.

Michael T

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Black_Diamond

My 350MAG MPI's take about 5.5 qts with a filter change, mind you this was draining the oil from the oilpan drain hole using the line attached to it out my bilge drain hole when I was on the hard.  Michael makes a good point: warm it up to drain, and better to under fill a bit and add then be over filled.

mvn

MT, 

Thanks for the pump info.   Here's a link to the Shurflo marine product line... . 

http://www.shurflo.com/marine-products/default.html

Mark

melvyn

greatly appreciated. I agree completely that fully synthetic oil will best protect an engine. know that all oil (synthetic in it. So it seems to me there are three basic classifications of oil "regular" mineral (with some added synthetic), semi synthetic and fully synthetic. I plan to eventually run fully synthetic in my twin 350 Mags. I have just finished putting 20 hours on them - breaking them in strictly by Mercruisers book. In the owners manual Mercruiser recommends a "first" oil and filter change at 20 hours. In the owners manual section on recommended oils Mercury`s number one choice is 20W-40 FULLY synthetic. Soooooo here's my question. I always thought that you should put at least 50 hours on an engine (to allow the oil control rings to seat properly and the bearings to seat properly). I have asked four techs I trust and got different answers some with conditions. I telephoned Mercury HQ and they said I was to follow the manual for warranty reasons.  The tech at Merc HQ said the fully synthetic oil was required to avoid phosphorus that will kill the catalytic converters and void the warranty. When I told the Merc HQ tech that I live in Canada and that my new 2013 Mercs were shipped here  (the last year we can get non-catalysed)  as non-catalysed he said to use fully synthetic anyway. Opinions appreciated.
Do as the service manual says until your warranty is up Fully syn is a real good oil but pick a good one mobile or shell