Odyssey Posted December 8, 2020 Share Posted December 8, 2020 Ok, My new friendly mechanic has been chatting me to me about oil. His veiw is this.... Quality of oil is dependant on quality of engine. If you are a leisure user doing 30 hours a year feel free to use cheap oil.... especially if you change it every year. If you run a “serious” engine (150hp+) use high grade. Outboards are different to cars, they can get hot, yes you are passing water through it but add salt/silt in there and it’s not as effective as you think. You can use standard oils but if you’re doing lots of hours don’t do it. It will cost long term. He had had my gear oil inspected and tested by an independent oil supplier. Previously Quicksilver gesr oil was used. I’m now moving up 2 grades. It will help lengthen the lifetime of the gear box seals too. He’s seen too many engines where the viscosity drops through use and this builds pressure on the seals which can lead to failure. He also strongly recommended using marine oil. In his words “it’s a couple of quid, but will cost far more once your seals go and gear box siezes under load”. It’s my choice but for the sake of: - £10 extra per engine oil x 2 - £5 extra for gear oil x 2 so £30 extra, why take the risk? If i was running 20-30 hours a year plodding along locally then I may reconsider as my usage wouldn’t require such high grade oil.... but I’m not. Im not judging anyone nor am I an expert just passing on my learnings/feedback 🙂 Saintly Fish and Andy135 2 Quote Link to comment Share on other sites More sharing options...
suzook12 Posted December 8, 2020 Share Posted December 8, 2020 Interesting comments there..... "He had had my gear oil inspected and tested by an independent oil supplier. Previously Quicksilver gesr oil was used. I’m now moving up 2 grades. It will help lengthen the lifetime of the gear box seals too. He’s seen too many engines where the viscosity drops through use and this builds pressure on the seals which can lead to failure" Now earlier I thought you were talking about going to a better spec oil such as a fully synthetic, now I realise you are talking about viscocity grades...... The second part of this makes no sense, yes oil thins as it gets used especially if the seals start letting water in, but building pressure? Its a splash lubricated gearbox, sorry mate, but sounds like he's blowing smoke up your arse. Maintaining viscocity is down to the oil spec/quality. The actual viscocity is worked out by moving part clearances at tep and cold. You are now in a scenario where your gearbox bearings may not receive the correct amount of lubrication, especially when cold, causing premature wear..... I would also take him to task where he states a leisure engine in minimal use can get away with a lower spec oil. I have found the exact opposite. A top quality oil will stick to components for a very long time, protecting them from excessive wear when started while waiting for the oil to get round, it will also withstand condensation from sitting far better as well. A commercial engine getting used every day doesn't need to worry about these...... As for marine engine oils, I have yet to see evidence that they are any different to non marine oils. Ignoring manufacturers blurb, and getting into oil analysis comparisons. Now, I'm not going to make the sweeping statement that this applies to ALL marine oils, but I have yet to see any evidence after many hours looking at comparisons. Sorry, but I would be having a word with your mechanic regards gearbox oil..... Shagged bearings will lead to blown seals due to allowing shaft to move. Seals can generally take 10psi with no issues (gearbox seals are tested with air pressure, 6psi iirc) Seals do wear out, its not rocket science, you have a rotating shaft going through it, shafts also wear too causing seal failure....... Just saying, but your call Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 8, 2020 Share Posted December 8, 2020 I’m not sure if it was viscosity or the oil breaking down.... he did explain in a lot of detail but I’m not a grease monkey.... Oil is runny stuff that goes in gear boxes and engines. When it gets hot it degrades. I don’t know much else about it. Its definitiatly a higher grade of gear oil that he’s using... Engine oil is a different conversation to be had! Ekectrivs are simple, I can talk for hours about them 🙂 greasy/oily things are the devils magic.... Your explainaruon sounds similar to what he was on about... I may just record it so you can translate into simple terms for this electronic engineer to work out 🙂 Bearings are fine apparently but the seals are known to go on those engines, hence the higher grade oil to look after them all.... This is why I pay a mechanic to deal with the moving bits. With electrics they can’t leak, cover you in muck, or confuse my brain with oils..... Quote Link to comment Share on other sites More sharing options...
suzook12 Posted December 8, 2020 Share Posted December 8, 2020 7 hours ago, Odyssey said: I’m not sure if it was viscosity or the oil breaking down.... he did explain in a lot of detail but I’m not a grease monkey.... Oil is runny stuff that goes in gear boxes and engines. When it gets hot it degrades. I don’t know much else about it. Its definitiatly a higher grade of gear oil that he’s using... Engine oil is a different conversation to be had! Ekectrivs are simple, I can talk for hours about them 🙂 greasy/oily things are the devils magic.... Your explainaruon sounds similar to what he was on about... I may just record it so you can translate into simple terms for this electronic engineer to work out 🙂 Bearings are fine apparently but the seals are known to go on those engines, hence the higher grade oil to look after them all.... This is why I pay a mechanic to deal with the moving bits. With electrics they can’t leak, cover you in muck, or confuse my brain with oils..... Fair enough. Maybe it's the use of the word "Grade", which is what is used describing viscocity....... Funnily enough, when I had my interview for college, they spent most of it trying to convince me to carry on with electronics and electrickery...... Needless to say, internal combustion won the day, although I still get heavily involved in vehicle electrics including loco's (well, did anyway). Had a 10 year stint welding after that, so been around the block a bit working on anything from cheap sh*tty Chinese scooters to mulimillion pound turbines and generators with most points in between...... Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 8, 2020 Share Posted December 8, 2020 Before my current job I was an expert in power electronics and electrical machines. as long as there was torque on that shaft controlled down to 0.1Nm from a 300Nm machine I didn’t mind what the grease monkeys did with their gear boxes with bearings, oil, gears, oil coolers, recirculating pumps and oil mist cooling..... mystery to me! Give me 3 cables to the motor and 400Vdc to my inverter and I could make it sit up and dance 🙂 JonC 1 Quote Link to comment Share on other sites More sharing options...
suzook12 Posted December 8, 2020 Share Posted December 8, 2020 25Kv ac makes people sit up and dance a bit, doesn't do a lot for quitting smoking tho!! 🤣 Quote Link to comment Share on other sites More sharing options...
Odyssey Posted December 8, 2020 Share Posted December 8, 2020 18 minutes ago, suzook12 said: 25Kv ac makes people sit up and dance a bit, doesn't do a lot for quitting smoking tho!! 🤣 I’ve seen enough smoke when 400Vdc went wrong.... had some big bangs when dumped a few thousand amps out of a battery. 25kV sounds much more interesting! Quote Link to comment Share on other sites More sharing options...
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