oil

[thebelly]

hi there im new to this ive had my boat around 12 months now ... love it.. im going to change my oil filter on my 1.5 bmc diesel engine .. what is the best grade of oil to use? ive got some 20/50 is this ok?

or does it have to be specificaly for diesel?

 

all the best

steve.....ashby canal.....

[twbm]

From a starting point that you should probably change the oil after about 200 hours running using a reasonable quality oil, you can use cheaper oil if you want to change it more often or better oil if you want to go longer between changes - but don't take chances with the engine for the sake of a few quid and change it once a year as a minimum. I understand oil intended for diesel engines is best as it contains additives to deal with the sulphur produced by diesel combustion. I don't think the viscosity makes a lot of difference in a marine installation.

[David Schweizer]

hi there im new to this ive had my boat around 12 months now ... love it.. im going to change my oil filter on my 1.5 bmc diesel engine .. what is the best grade of oil to use? ive got some 20/50 is this ok?

or does it have to be specificaly for diesel?

 

all the best

steve.....ashby canal.....

The oil does need to be suitable for older style Diesels and should be rated at API CC/SD. There are two schools of thought about the grade of oil to be used on a BMC 1.5. Some (myself included) use straight 30 SAE whilst others prefer 10/40SAE or 20/50SAE. it is down to choice although some people reckon that the multigrade is better for worn engines because it reduces smoking.

 

Many people (again myself included) swear by Morris Oil which has a good track record, whilst others will scour supremarkets for a cheaper non branded supply, which is fine if you trusrt the supplier. Personally I prefer to rely upon a proven brand. As already indicated, the correct period for oil change on tyhe BMC 1.5 is every 200 hours, leave it much longer than that and the engine will start to complain.

[alan_fincher]

The oil does need to be suitable for older style Diesels and should be rated at API CC/SD. There are two schools of thought about the grade of oil to be used on a BMC 1.5. Some (myself included) use straight 30 SAE whilst others prefer 10/40SAE or 20/50SAE. it is down to choice although some people reckon that the multigrade is better for worn engines because it reduces smoking.

 

Many people (again myself included) swear by Morris Oil which has a good track record, whilst others will scour supremarkets for a cheaper non branded supply, which is fine if you trusrt the supplier. Personally I prefer to rely upon a proven brand. As already indicated, the correct period for oil change on tyhe BMC 1.5 is every 200 hours, leave it much longer than that and the engine will start to complain.

David's answer is a good and fair one, and there has been much debate about the use of a monograde versus a multigrade in these engines.

 

As the original manufacturers handbook basically allowed either in automotive use, it's hardly surprising it remains a flexible decision in a marinised engine.

 

Having used both a SAE 30 monograde as well as 10W/40 and 20W/50 at various times, I go the other route to David, and use a multi-grade. We tended to "use" some oil with the SAE 30, but hardly ever top up with the multigrades. Also the multi-grade really does seem to make winter starting easier on our engine. Our engine is 15 years since a rebuild, but doesn't show a lot of symptoms of being worn, so the jury is out for me whether 10W/40, or the thicker 20W/50 recommended for worn engines is better. I'm currently using 20W/50, and do notice that when the engine is fully hot, the minimum oil pressure at idle is slightly higher. But it was still within acceptable levels with the thinner oil, so I'd be happy to switch back.

 

I personally am convinced the API-CC thing is important with these engines, although some argue otherwise. Most cheaper oils from Halfords, and the like are at least API-CF, AI-CG, or API-CH. A search of old threads will find compelling arguments why you are better sticking to an oil with a spec specifically blended for old technology engines.

 

Like David, I generally use a Morris oil, (even the much marketed Lister Petter API-CC oil is actually blended by Morris, even though the packaging doesn't tell you this. That oil, for example, is fine ina BMC.

[RobinJ]

hi there im new to this ive had my boat around 12 months now ... love it.. im going to change my oil filter on my 1.5 bmc diesel engine .. what is the best grade of oil to use? ive got some 20/50 is this ok?

or does it have to be specificaly for diesel?

As has been said, should be API CC grade, but doesn't really matter whether multigrade or not.

The older engines generally work better with straight 30, but I think it depends on length of boat, prop size, range of temperature and running conditions. Multigrade seems to work well when the engine is not under heavy load and has a good cooling system, straight 30 will maintain oil pressure at high temperatures and reduce smoking, but can make it more difficult to start in cold conditions.

You don't say whether its an old BMC, new one or a variety like Thornycroft?

[mayalld]

Many people (again myself included) swear by Morris Oil which has a good track record, whilst others will scour supremarkets for a cheaper non branded supply, which is fine if you trusrt the supplier.

 

Probably a good point to interject that B&Q are currently selling an API-CC rated oil for £10.99 per 5l

[journeyperson]

Probably a good point to interject that B&Q are currently selling an API-CC rated oil for £10.99 per 5l

 

Yes, Carlube Daytona which I have used several times and is fine in my Lister-Petter LPWS3. I am currently using Carlube 10/40 CF grade mineral oil and the engine is very happy on it.

[larkshall]

As a longtime user of BMC engines in many applications, I stick to branded multigrades. SAE 30 is ok, but the multigrades operate better over a wider temperature range, and boat engine installations vary much more than automotive or agricultural in this respect..

 

Diesel detergent oils are designed for later engines than BMC, and evidence is mixed as to the benefits of using them on BMC units. On a recent fully reconditioned unit probably ok, on a slightly worn unit then no. (the detergents, can release solid bits of carbon crud, which will circulate through then engine prior to capture by the filter. some oilways (crank journals, oil control rings on pistons etc), could become temporalily occluded during this process, and exacerbate wear for a few seconds...not really worth the risk in my view

[alan_fincher]

Probably a good point to interject that B&Q are currently selling an API-CC rated oil for £10.99 per 5l

 

 

Yes, Carlube Daytona which I have used several times and is fine in my Lister-Petter LPWS3. I am currently using Carlube 10/40 CF grade mineral oil and the engine is very happy on it.

Being totally pedantic, but if you mean the carlube Daytona 20W/50 one, then you actually only get 4.5 litres for your money, not 5 litres.

 

Also that one is £10.98 not £10.99

 

There has been a suggestion that this could be a remanufactured oil, but I can't comment on this.

 

It seems to be being sold for lawnmowers, as you'll generally find it in that section, not the car section.

 

Personally I decided spending a few quid more on the known quality of a Morris Oil wasn't a lot of money in the big scheme of things, but the Daytona oil is probably fine.

[journeyperson]

>snip<

Also that one is £10.98 not £10.99

 

>snip<

 

Or £9.88 if I go today and use my over 60s Diamond Card; the place will be crawling with pensioners though...

[Grace and Favour]

Or £9.88 if I go today and use my over 60s Diamond Card; the place will be crawling with pensioners though...

 

Oh - you want to stay away from pensioners, they inevitably smell of p, and sometimes even of boats!

 

(- -)

[thebelly]

thanks for all that information... quite a range of oils really then.... im off to get some now... and change it every 200 hrs or so as suggested...

thanks

steve.... (the belly) ashby canal

[leolady too]

I was advised to use Castrol Agri power plus from an agricultural merchant. Its sold to farmers for tractor engines. Many of the exploded diagrams for my engine (Beta BD3 Tug) have "John Deere" written across the top so it seems appropriate. I buy it in a 25l mini barrel which is expensive (can't remember how much for the last one) but cheaper per litre. It's obvioulsy sold for tractors which are usually worked hard and many of which seem to go on forever so I think it's probably OK for a boat engine. Check the nearest agricultural merchant.