Steve_N
Well-known member
Loads of places but here's one for starters.
https://www.ebay.co.uk/itm/MANNOL-S...l-Engine-Oil-10-Litres-API-CF-SL/123056967469
Yanmar 2GM20 Oil
- Thread starter Daverw
- Start date
Loads of places but here's one for starters.
https://www.ebay.co.uk/itm/MANNOL-S...l-Engine-Oil-10-Litres-API-CF-SL/123056967469
richardabeattie
Active member
Bingo!
Tranona
Well-known member
In my engines I'm using use DOT5.1 brake fluid, GL5 gear oil, OAT antifreeze, synthetic oil, silicone hoses, nitrile seals, etc etc etc, none of which are recommended by the engine manufacturer ..... for obvious reasons.
As for "killing engines", quite the opposite. My engines have all been running on synthetic for 40 years, look like brand new internally, have zero oil consumption, have never had to replace an engine bearing, all run without any bearing wear noise and all do over 100k miles. If that's killing them, then I'm all in favour of death.
Richard
Cannot understand why you constantly talk about car engines running 100k miles when everybody else is talking about little (crude by comparison) diesel engines used in boats that never run anywhere near that kind of hours and operate under completely different conditions.
Just a couple of key figures to show that these two situations are so far apart. The typical specific output of our diesels is 35 - 40hp per litre displacement. For at least 30 years automotive engines have been twice that as a minimum and now often 3 or even 4 times that. 100k miles is roughly 3500 hours (20+ years of yacht use!) - but less than half the expected life of your Yanmars. My last Volvo did those hours using mineral oil and I expect if you stripped it you would find it exactly the same as the internal of your car engine. In other words it was running as well as it did when new, and never burned any oil.
Your car engines (and mine) need the more advanced oils - that is why they were developed. Small diesels DO NOT - as the two major oil companies quoted above say (and all the manufacturers who make the engines)
Sorry to say Richard, but you are falling into the trap of taking your experience from one set of circumstances and trying to apply it to another. Your experience with your automotive engines is simply not relevant. You have not provided any evidence of any advantage from using synthetic oil in your Yanmars.
BTW there is nothing exceptional about your experience with your car engines either. I would be very disappointed if a modern engine did not run mechanically trouble free without any wear for a mere 100k miles. What surprises me most is that you had the need to strip them down anyway.
JumbleDuck
Well-known member
Yes, but remember that marine diesels are often running at a significant proportion of full power while car engines very rarely get anywhere near their maximum rated power - and those which do spend a lot of time there tend not to last long. Particularly anything managing 160hp per litre.
Tranona
Well-known member
Not true. Typical cruising speed of a matched auxiliary engine is around 70% maximum power. The big difference is that marine engines run mostly at constant speed whereas many automotive engines do lots of stop start, heavy acceleration, cold starts etc. The engines that survive the best are those that do high motorway mileage which is not unlike marine usage. Another interesting comparison is diesels like ours that are used in construction equipment where they typically run 2-3000 hours a year for 4- 5 years without any trouble and i expect their insides will be similar to Richard's car engines.
JumbleDuck
Well-known member
Plenty of online suppliers (https://www.smithandallan.com/produ...892-smith-and-allan-ultra-15w-40-engine-oil-/) but getting harder to find on the shelf. Halfords, for example, list 83 engine oils of which only 5 are mineral-based. Tesco dropped their CF a couple of years ago. When I needed it, I tended to buy in bulk at Lidl, which gets it a few times per year. A good motor factor should still have it, or be able to get it.
JumbleDuck
Well-known member
Not true? That was precisely my point. No car engines in normal use run at 70% maximum power for more than a tiny fraction of the time. Sure, they lead a rather more varied and interesting life, but almost all of it at very low power.
PaulRainbow
Well-known member
In my engines I'm using use DOT5.1 brake fluid, GL5 gear oil, OAT antifreeze, synthetic oil, silicone hoses, nitrile seals, etc etc etc, none of which are recommended by the engine manufacturer ..... for obvious reasons.
Let's stick to boat engines, car engines are irrelevant.
As for "killing engines", quite the opposite. My engines have all been running on synthetic for 40 years, look like brand new internally, have zero oil consumption, have never had to replace an engine bearing, all run without any bearing wear noise and all do over 100k miles. If that's killing them, then I'm all in favour of death.
Richard
please re-read what i said, then change all of your engines over to detergent oil, post back how many survive, i'll wager........none
RichardS
N/A
Best start re-reading Paul. You said "I find it hard to understand why anyone would use an oil that is a different spec to that which the manufacturer of the engine states should be used". I have already explained why I use an oil to a different spec but have then extrapolated the point to illustrate lots of other manufactures recommendations which I studiously ignore .... and that's a perfectly relevant point. :encouragement:
By the way, aren't most people with old engines which recommend an obsolete grade of oil now using something something not recommended by the manufacturer simply because they cannot get hold of the ancient grade? It's called "taking advantage of technical progress".
Please see my post #37 re high detergent oils.
Richard
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JumbleDuck
Well-known member
By the way, aren't most people with old engines which recommend an obsolete grade of oil now using something something not recommended by the manufacturer simply because they cannot get hold of the ancient grade? It's called "taking advantage of technical progress".
Well, exactly. I don't think many classic car owners are running on 30 monograde ...
RichardS
N/A
Let's leave this now as I obviously failing to explain the most obvious benefit of using synthetic oil in any internal combustion engine and I don't want to keep repeating myself. There are many reasons why one would need to strip down an engine sufficiently to see the internals either at the top or bottom end but that's beyond the scope of this thread.
Richard
awol
Well-known member
I find Castrol R40 is ideal for my Yanmar and is appreciated by those in my wake :wink-new:
PaulRainbow
Well-known member
By the way, aren't most people with old engines which recommend an obsolete grade of oil now using something something not recommended by the manufacturer simply because they cannot get hold of the ancient grade? It's called "taking advantage of technical progress".
Richard
I think we all know that's not what i meant. There is a big difference between using an updated spec oil, such as using CH where the service book says CD and using semi-synthetic, fully synthetic or high detergent oils. When an engine was built at a time when CD was the best oil for that particular engine the book obviously doesn't specify CH, because that hasn't been invented yet. But even todays small boat engines still specify 15/40 mineral oil. Go buy a brand new VP D series and they specify VDS-3, same as Yanmar, Beta et al.
If semi or fully synthetic oil was the best thing for these engines the manufacturers would specify them.
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MagicalArmchair
Well-known member
Oil is one of those delightful and divisive subjects! Whether you are on a automotive or boat forum it almost summons up as much passion, angst and teeth gnashing as the dreaded and equally wonderful anchor debates (we haven't had one for a while? ).
Cracking, good effort all!
).Cracking, good effort all!
PaulRainbow
Well-known member
Oil is one of those delightful and divisive subjects! Whether you are on a automotive or boat forum it almost summons up as much passion, angst and teeth gnashing as the dreaded and equally wonderful anchor debates (we haven't had one for a while?
Cracking, good effort all!
What oil should i use on my CQR pivot pin ?
Tranona
Well-known member
Let's leave this now as I obviously failing to explain the most obvious benefit of using synthetic oil in any internal combustion engine and I don't want to keep repeating myself. There are many reasons why one would need to strip down an engine sufficiently to see the internals either at the top or bottom end but that's beyond the scope of this thread.
Richard
The reason why I (and most others) are not convinced is that you have completely failed to show ANY benefits of using synthetic oils in small marine diesels. You are alone (at least here) in claiming such benefits - but what are they?
For example you claim that your (high powered) car engines show no wear at 100k miles - which I have shown is less than half of the expected life of a marine engine. How does that "prove" anything? Different design of engine, different use and running on the oil recommended by the manufacturer.
We read your claim every time this subject comes up and you never actually say what this "OBVIOUS" benefit is. Surely if it was obvious you could state what it is and provide evidence to support your claim? Instead you go off topic and talk about high powered road car engines.
It is only you that claims synthetic oil has a benefit for "any internal combustion engine". I find this surprising as all the major oil companies disagree - we have 2 examples on this thread, each giving a considered explanation for their position.
So your failure to explain yourself and convince others seems to be because you don't have an explanation, never mind evidence.
Tranona
Well-known member
My 2 litre Ford diesel cruises at 2000 rpm (70mph) on a motorway for hours on end. It is using around 80 bhp (out of 138). This is somewhat similar to cruising with my Volvo in the boat.
I agree many high powered cars do not cruise that far up the power band. However it is not steady rpm use that causes wear. It is cold starts followed by running up and down the rev range, followed by periods of idling etc that shorten the life, although even then 100k life as I showed earlier is less than half of a typical small diesel.
As we know what kills yacht auxiliaries is the pattern of usage. Long periods of no use followed by short runs, often at light loads. 100 hours a year is roughly equivalent to 3000 road miles. Despite that 30-40 years life seems to be quite normal.
JumbleDuck
Well-known member
My scruffy old Citroën Berlingo cruises the motorway for hours on end at 70mph, using much less than the measly 60hp it has available. I think you are greatly overestimating the power your car uses at that speed. Dammit, I had a 2CV which would cruise at 70 all day on 29hp.
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awol
Well-known member
Fixed that for you!
I had one as well and overtaking on an uphill could be a long and tedious experience for those behind.
JumbleDuck
Well-known member
I took mine over the Hardknott and Wrynose passes. No problems at all, and we got a round of applause from a groups at the very top. Ah, I miss that car.