Whats the difference. Have your tried doing it this way

[davidk65]

Engine Oil Grades:

When I bought our boat I was told to use diesel engine oil 15-40. I have continued to do this when servicing the 3 cylinder Nanni engine ( the same oil goes in the gear box).

Last year when RCR carried out the annual inspection they recommended I use a 10-40 oil (but not any synthetic oils) but I was not able to understand why the change of grade. It's oil change time again and I am not sure if to use the 15-40 or the 10-40 diesel oil.

Question: Can anyone explain why and what difference it would make.

 

Stern Gland Packing:

Instead of cutting individual packing rings, Tony Brooks on his website ("The cheats way" he calls it) suggests winding the packing around the shaft in one piece, stressing it must be wound in the direction of forward rotation so that the packing would in effect tighten slightly with rotation of the shaft and prevent the entry of water into the boat.

Question: Has anyone tried this method and was it sucessful?

 

Davidk65

[alan_fincher]

Stern Gland Packing:

Instead of cutting individual packing rings, Tony Brooks on his website ("The cheats way" he calls it) suggests winding the packing around the shaft in one piece, stressing it must be wound in the direction of forward rotation so that the packing would in effect tighten slightly with rotation of the shaft and prevent the entry of water into the boat.

Question: Has anyone tried this method and was it sucessful?

This has been debated in a previous thread.

 

Personally, I'd be suspicious.

 

Your packing is normally squeezed between two completely flat surfaces, front and rear. (At the rear, within the fixed part of the stern gland, and at the front by the moving part that compresses down).

 

So if you use the normal method of a number of cut rings, these should also lie at exactly 90 degrees to the shaft, and be evenly compressed.

 

Surely if you "spiral", there is a potential issue where the spiral starts and ends, as you will have a point where the very end, buts up against the next turn, which will then be held away from the two compressing surfaces by a distance of one thickness of the compressed packing. At best the packing is going to distort by uneven amounts to try and fill this space.

 

Whilst what TB says may work, why deviate from the standard method - it's only saving you making two or 3 cuts, after all ?

[Alec Gatherer]

In simple terms the 15/40 oil will be thicker when hot, thus giving you slightly higher oil pressure reading (but not necessarily better lubrication properties).

In the old car world there is a perception that the more used the engine the larger the gaps round the bearings, and so the thicker the oil the better. I would tend to carry this thought through to your boat engine, but stand ready to be advised by someone with greater knowledge of your engine.

[Supermalc]

I've recently discovered multigrade oils are thin oils thickened, so a 10/40 oil is actually a 10sae oil.

 

The first multigrade oils readily available were 20/50 oils, whereas now 15/40 seems to be the common.

 

Unless used in extreme cold conditions, with the engine becoming difficult to turn over, I see no reason to use thinner oil (however I'm not an expert, and have little knowledge of modern engine technology).

 

As oil technology progresses, it should be safe to assume the latest, and best oils should be the ones to use. However this is not always the case, for example synthetic oils can damage the bearings of some older engines.

 

Cannot the engine manufacturer recommending the change of oil not supply the relevant information as to what is the best to use, and why the change?

[DHutch]

Cant really advise on the engine-oil, but for the STG packing i would always do it in rings, with the joins at 90 or 180 degrees to each other.

- You dont eaxctly do it often, so id be aiming to do the best job, not the quickest.

 

 

Daniel

[timboharticus]

Alex "In simple terms the 15/40 oil will be thicker when hot, thus giving you slightly higher oil pressure reading (but not necessarily better lubrication properties)."

 

I don't think this is the right way around. The oil will be thicker when cold.

 

The oil acts as a hydraulic cushion between surfaces. Thicker oils are more suitable when the gap between bearing surfaces is large, thinner oils are better when they are small (tighter tolerances).

 

Thick oil causes more drag and does not circulate as easy.

 

Modern engines require thinner oils because of the tighter tolerances to which they have been made.

 

The correct oil to use is the grade recommended by the engine manufacturer for the engine and type of use.

 

I use straight SAE 30 or 20/50 in my BMC 1500. I have been told that using high performance oils with lots of additives causes bores to glaze up, since they tend to idle for long periods. The API number indicates the level of additives. API CC has low additives and I use this. Can't remember other grades , but EE EF etc would have more additives,detergents etc. for use in turbo diesels, lorries etc.

 

One other point , a straight oil ie. SAE 30 or 40 will maintain its viscosity for longer, whereas multigrades can deteriorate quickly of overheated, or get chopped up by camshafts etc.

[bottle]

Viscosity (Engine oils)

In the early days of the IC engine there were only monograde oils (e.g., SAE 20, SAE 30, SAE 50). By putting an additive into these oils, called a VI improver, multigrade oils were created. The VI (viscosity index) improver is a flexible molecule, rolled up like a ball at low temperature and stretched out like a string at high temperatures. This allows the oil to remain viscous at high temperatures. One can recognize multigrade oils as being represented by two figures. The first figure, followed by the suffix ‘W’, stands for the viscosity calss at low temperature (W = winter). The second figure is the SAE class at working temperature. Thus, for example, ‘SAE 20W-50’ means that the viscosity of the oil at low temperature corresponds with a SAE 20W, and the oil viscosity at 100°C corresponds with a SAE 50.

 

This was taken from this Wearcheck website

 

Higher the number the more viscous(thicker) the oil.

[Alec Gatherer]

Alex "In simple terms the 15/40 oil will be thicker when hot, thus giving you slightly higher oil pressure reading (but not necessarily better lubrication properties)."

 

I don't think this is the right way around. The oil will be thicker when cold.

 

With regard to Bottle's very apt signature:

No, I was right , honest. I just wasn't expansive enough. The more accurate meaning behind my simplistic reply was " the 15/40 oil is thicker when hot than the 10/40 oil when hot".

Guilty of assuming that people would realise what I meant.

[DieselDuck]

" the 15/40 oil is thicker when hot than the 10/40 oil when hot".

 

Surely you mean when cold, the first/lower figure refering to the viscosity when tested at zero degrees c, the second/higher figure

refering to viscocity when tested at 95 degrees c, hence both oils

are a 40 when hot, the 15/40 being thicker when cold.

[Alec Gatherer]

You could be turning my acquired wisdom on its head here. I had always assumed that the high figure, e.g. /50, was when measured cold, and the lower figure, e.g. 15/, measured when hot. My assumption was based on the belief that the higher the figure the thicker the oil, and the fact that all the lubricant oils I have encountered were thickish when cold and thinnish when hot.

I use SAE 20 oil (which is like water) in carb. dashpots, and SAE 140 (which is like treacle) in gearboxes. On cars, of course. In engines I use 20/50, which is thick when cold and thin when hot.

As usual I await enlightenment.

[Mick and Pauline]

You could be turning my acquired wisdom on its head here. I had always assumed that the high figure, e.g. /50, was when measured cold, and the lower figure, e.g. 15/, measured when hot. My assumption was based on the belief that the higher the figure the thicker the oil, and the fact that all the lubricant oils I have encountered were thickish when cold and thinnish when hot.

I use SAE 20 oil (which is like water) in carb. dashpots, and SAE 140 (which is like treacle) in gearboxes. On cars, of course. In engines I use 20/50, which is thick when cold and thin when hot.

As usual I await enlightenment.

 

Hi Alec,

 

I think I am with you on this one because in my BSA / Truimph days of two wheels. I was told that during cold weather lub oil was thicker and did not flow properly until the engine warmed it up. So the boffins can up with the lub additive (the molecule bit) and called it Multigrade Lub Oil. That allow the lub oil to be thinner at cold temperatures (20 SAE) but when the engine warmed up it still was thick enough (50 SAE) to lubricate the engine. Just in passing the SAE means :- Society of American Engineers, who I think they were the first to grade lub oil into numbers for it's thickness.

 

M & P.

[Callum]

Having had a bit of a Google around I think DieselDuck has it right.

 

The numbers refer to the thickness/viscosity of the oil at a given temperature. So for non-multigrade oil an SAE 40 oil is thinner than SAE 50 oil when hot (I think 100C is the temp the rating is taken at).

 

The W numbers in multi-grade oil refers to the viscosity of the oil when cold (zero C, I believe).

 

So, a 10W-40 oil has the same viscosity when hot as a 15W-40, but is thinner than the 15W-40 oil at low temp. NOTE: Because the 10W/15W are measured at low temp and the 40 at high temp it does not mean that either oil is thicker at high temp than at low temp.

 

Callum

 

PS Sorry if I've overdone the Bold

Edited June 26, 2006 by Callum

[DieselDuck]

As usual I await enlightenment.

 

Viscosity is a measure of resistance that an oil offers to flow and not in

any way connected to the effieciency of the oil as a lubricant.

Determined by experiment under controlled conditions by the Society of

Automotive Engineers (america), dependant on its flow rate, it is awarded an SAE number. Monograde oils are usually tested at 95 degrees, multigrade oils at 0 degrees & 95 degrees hence in the old

days you would see 20W/50, the W (now dropped) denoting Winter use.

Also, hope you run a very old car, as more modern vehicles require

something a little thinner! ( taken from my City & Guilds course notes)

[dor]

I agree with diesel duck. As I understand it, a 15/40 behaves like a 15 when cold and a 40 when hot. Thus when hot it will be thicker than if it was just a straight 15, and it will be thinner than a straight 40 when cold.

 

For all these old mitsubishi/BMC/ford engines, not to mention the trad engines, I gather that the thing to look for is API CC. This basically means that it has very little in the way of modern additives, which are the cause of bore glazing.

 

So when you see someone running their engine in gear who knowingly tells you that they have to run under load or their bores will glaze you can tell them, even more knowingly, that they are using the wrong oil.

[DieselDuck]

Getting back to the original question on oil, the viscosity is not the main issue.

You could use the 15/40 in summer and the 10/40 in winter if you wished. However, what

is more important is the API classifcation, CC, CD, CE etc. You should use the oil with an

SAE Grade in your areas temperature range, usually shown in the engines manual, but

with narrowboat engines, which generally run at idle or not much above it, the API

spec becomes more important. This is the amount of additives in the oil which are usually

too agressive in modern oils or do not work correctly because they require the higher running

temperatures of high speed diesel engines found in automotive use, which leads to the bore glazing

refered to.

I myself have found it a little difficult to find a `low spec` oil suitable for NB Engine use, unless

you buy the Engine manufacturers packaged oil, as most oils sold are for modern cars/trucks.

A good independant oil supplier will be able to supply low spec oil at a good price, but usually

only in 20 - 25 litre quantities.

I have a Barrus Shire built in 1999, but this requires a 10/40 CC oil. Not exactly off the shelf

stuff from Halfords, but not impossible to source. I use SP Lubricants in Wimborne, Dorset

myself.

[Keeping Up]

My engine (Perkins) specifies 10/40 or 15/40 to spec API-CC. The trouble is I can find either of these viscosities as CF; and B&Q sell CC but it's 20/50 and'm worried that that would be too thick for the engine. So I'm still searching.

[alan_fincher]

My engine (Perkins) specifies 10/40 or 15/40 to spec API-CC. The trouble is I can find either of these viscosities as CF; and B&Q sell CC but it's 20/50 and'm worried that that would be too thick for the engine. So I'm still searching.

Not cheap, but something like this, perhaps ?.......

 

Link to MC web page

[DieselDuck]

Try a search for suppliers of Exol Lubricants, they do a 10/40 & 15/40 CC in their `Classic` range.

Most Independant Oil Suppliers can have oil made to your specs if you require and they still don`t come

out as expensive as modern `off the shelf` products. If you don`t want 25 litres, most NB engines

seem to require these low spec oils, why not get together with a few local boaters and go for what

you need. I feel I can`t quote prices so as not to tread on retailers toes, but as I said above, 5 litres

each between 5 people would be about 10 - 12 each inc VAT if bought in this way.

 

I type too slowly, but alans link looks the biz!

Would`nt say it was dear considering it`s going in yer engine for 200 hrs or a year or so! and demand for

this spec oil is low in comparison for the manufacturers to make loads.

Edited June 26, 2006 by DieselDuck

[Keeping Up]

Thanks guys - I was baulking at the price a bit, given that the 20/50 API-CC from B&Q is only £5 for 5 litres, but the right thing is never cheap is it?

 

I use about 20 litres a year anyway so if I had to buy 25 litres or even 50 it wouldn't really be a problem! That's about 650 hours cruising so 3 oil-changes, plus about 5 litres that goes in smoke or leaks during the year.

[David Schweizer]

Since Castrol discontinued their Diesel RX oil some years ago, I have been using Morris Lubricants Supreme 30 API CC oil, which is designed specificly for older diesel engines which are run at comparatively low speeds and under light load. It should be available at any decent Chandlery, the last lot cost me £10.50 for five litres from Midland Chandlers.

Edited June 27, 2006 by David Schweizer

[Cafnod]

Since Castrol discontinued their Diesel RX oil some years ago, I have been using Morris Lubricants Supreme 30 API CC oil, which is designed specificly for older diesel engines which are run at comparatively low speeds and under light load. It should be available at any decent Chandlery, the last lot cost me £10.50 for five litres from Midland Chandlers.

 

 

Hi David

I have used Morris oils for all sort of vintage engine applications, 2 stroke Commer (TS3) diesel and various vintage/veteran motorcycles.

Never had a problem with it.

The reason the multigrades were developed in the states is cos of the huge disparity of temperatures in the US and Canada, you can easily have to deal with - 40 to +30 in a year.

And if anyone else on this site has driven an old lorry where on a cold morning the oil was so thick you could not get a gear then you will understand........................

[Enfield Phil]

So what oil should I be putting in my BMC 1.5 ?

[Sir Nibble]

So what oil should I be putting in my BMC 1.5 ?

Duck knows.

[alan_fincher]

So what oil should I be putting in my BMC 1.5 ?

Been there ! Done that ! (Or at least for a BMC 1800, which is going to have same requirements.....)

 

If you scan through previous posts, you'll find one group of people recommending a simple, (though that doesn't mean cheap!), monograde like the Morris Supreme SAE 30, (as David has just done - his engine is the BMC 1500).

 

But equally, you'll find other people saying it has caused them problems, and they have improved things by switching back to a multigrade.

 

Don't expect to do any better if you ask the experts, either.....

 

When I asked Morris Oils for a recommendation they came down in favour of the Supreme 30 Monograde.

 

But when I asked Calcutt boats, the original mariniser of my engine, (and still doing the Turkish built equivalents now), they said they wouldn't recommend that at all, and said I should definitely use a MULTIGRADE in a 10/50 or 20/50 spec, (and went as far as suggesting certain names from the Morris range.....)

 

So what do you do ?

 

I asked the engineer at the marina, and he said he would always use the multigrade, but the most imprtant thing was to go for an API-CC spec - definitely nothing higher, as these do not suit these older engines. That, incidentally, seems to be the one common bit of consistent advice - whatever you put in - don't make it API-CD, API-CE, API-CF, etc, (although many of these say they exceed an API-CC spec).

 

I've started topping up with the stuff branded as Lister Petter, which is I think 10W / 40 multigrade, (i'll check when next there), and certainly an API-CC spec. (I'm told this is formulated by Morris Oils, anyway, despite not being badged as such on my can).

 

I don't know if it's definitely connected, but I seem to be hardly needing to put any in since switching to this, but when I was using a can of the straight SAE 30, originally on the boat, I was doing it much more regularly, I'm sure.

 

I hope I haven't confused more than helped

[David Schweizer]

So what oil should I be putting in my BMC 1.5 ?

I used to use Castrol Diesel RX 20W/40 until they discontinued it, then I used Landrover 20w/40 until I couldn't get that any more, now I use Moris's Supreme 30 API CC, which is what they recomended. 20W/40 or 20W/50 would probably be just as good if you can find one that is designed for diesels and is no higher than API CC. The original workshop manual for the BMC 1.5 offers several alternatives which includes both these multigrade and monograde options.

 

Several people have indicated that the API rating should be no higher than CC. This is correct as higher grades contain more detergents and additives which will cause bore glazng in older diesels constantlly running at lightly loaded low speeds.

 

The advice from Calcutt to only use a multigrade is undoubtably correct for their new and re-manufactured BMC 1.5 engines, but if you have an elderly engine which has done a fair number of hours it might be better to use a monograde, either will do the job but one might cause a bit more smoke than the other, the only way to find out is to try both.

 

As an aside does anyone out ther have a BMC 1.5 that does not smoke when the power is put on after a period of idling at tickover?

Edited June 28, 2006 by David Schweizer