Modern diesel in old engines

[Toe Rag]

Recent reports on the reducing of sulphur and increasing of biodiesel worry me.

Currently in the 'fleet' I have a RN DM2 pre-war and a Ruston Hornsby 2VSH built in the 1940's.

These engines have lots of brass components and very old seals in the fuel systems.

The suggestion is that the latest spec diesel may attack these components.

Has anyone any experiece of using additives and if so which ones?

Has anyone actually had any failures due to the low sulphur and high bio-fuel diesel?

 

By the by I did use Forte Diesel conditioner in the Ruston some years ago.

The results were disappointing and she has smoked more ever since.

I guess it cleared out any accumulations here and there which were probably helping everything seal and seat nicely!

[RobinJ]

Recent reports on the reducing of sulphur and increasing of biodiesel worry me.

Currently in the 'fleet' I have a RN DM2 pre-war and a Ruston Hornsby 2VSH built in the 1940's.

These engines have lots of brass components and very old seals in the fuel systems.

The suggestion is that the latest spec diesel may attack these components.

Has anyone any experiece of using additives and if so which ones?

Has anyone actually had any failures due to the low sulphur and high bio-fuel diesel?

Didn't think there was a problem with fuel?

Have experience of what oil additives can do to brass components though!

[steamraiser2]

Some bio-diesels, particularly the made in the shed stuff, can be a little acidic and can certainly play up with some engines. More usually in modern ones than proper engines.Usually engine ill effects are caused by the ability of fuel oil to wash the lubricant off the top of the bores causing wear.

 

Remember that modern diesel fuel, sulphur reduced, additived to death or not is of far higher quality and cetane rating than the waxy fuels they were designed to run on during the 40s and 50s.

 

The only additive they used in the old days was a gallon or two of kerosene or paraffin to combat wax drop out in very cold weather. Cold pour point is the modern fancy name. You can spend loads on CPP additives..kerosene is cheaper!

[oasis]

In a previous life I was a marine Chief Engineer - Foreign Going (now that's going back years) and I sailed as such until I was 25 to 27. The one tanker I was on had 2 * 15000Kw diesels and their fuel specs included a sulphur content requirement of - from memory - say 0.5%. This was for the fuel pump lubrication, without this sulphur content we had pump seizure after seizure. (I certified as a Mechanical Engineer to get ashore and 2 yrs later as an Electrical Engineer and a decade later I got a B.Comm.)

 

The main maintenance requirements I read about and agree with are periodic oil changes; with a lightly loaded diesel engine such as on a narrow boat on the cut, the engine does not burn the total diesel injected. What happens is a cylinder liner "wash" which removes cylinder boundary lubrication and increases liner wear if oil is not kept up to spec. This degrades the oil and the KoH. and viscosity drops and other nasty things happen. But with no sulphur the residues are not a problem, the SOx disappears and acids disappear that could form with any moisture residual in the oil. With a highly loaded engine with an exhaust temp over say 420C then pentoxides form which lower the melt point of the exhaust valve metal and cause failures as well. (CHAPS _ PLEASE HELP HERE, I AM 35 YRS AWAY FROM WHEN I LAST STUDIED THIS)

 

My thoughts on modern diesel in old engines are that - in the main - the old designers were aware of the benefits of having a pre combustion stage, they knew about cylinder lubrication requirements, they spec'ed a higher KoH etc because of the sulphurs they had to contend with and their valve materials could cope with sulphur at lower revs.

[oasis]

In a previous life I was a marine Chief Engineer - Foreign Going (now that's going back years) and I sailed as such until I was 25 to 27. The one tanker I was on had 2 * 15000Kw diesels and their fuel specs included a sulphur content requirement of - from memory - say 0.5%. This was for the fuel pump lubrication, without this sulphur content we had pump seizure after seizure. (I certified as a Mechanical Engineer to get ashore and 2 yrs later as an Electrical Engineer and a decade later I got a B.Comm.)

 

The main maintenance requirements I read about and agree with are periodic oil changes; with a lightly loaded diesel engine such as on a narrow boat on the cut, the engine does not burn the total diesel injected. What happens is a cylinder liner "wash" which removes cylinder boundary lubrication and increases liner wear if oil is not kept up to spec. This degrades the oil and the KoH. and viscosity drops and other nasty things happen. But with no sulphur the residues are not a problem, the SOx disappears and acids disappear that could form with any moisture residual in the oil. With a highly loaded engine with an exhaust temp over say 420C then pentoxides form which lower the melt point of the exhaust valve metal and cause failures as well. (CHAPS _ PLEASE HELP HERE, I AM 35 YRS AWAY FROM WHEN I LAST STUDIED THIS)

 

My thoughts on modern diesel in old engines are that - in the main - the old designers were aware of the benefits of having a pre combustion stage, they knew about cylinder lubrication requirements, they spec'ed a higher KoH etc because of the sulphurs they had to contend with and their valve materials could cope with sulphur at lower revs.

 

God - after reading this I have to stay away from France with wine at 2 Euro a bootlay!!!!!!!!!!!

[LEO]

Recent reports on the reducing of sulphur and increasing of biodiesel worry me.

Currently in the 'fleet' I have a RN DM2 pre-war and a Ruston Hornsby 2VSH built in the 1940's.

These engines have lots of brass components and very old seals in the fuel systems.

The suggestion is that the latest spec diesel may attack these components.

Has anyone any experiece of using additives and if so which ones?

Has anyone actually had any failures due to the low sulphur and high bio-fuel diesel?

 

By the by I did use Forte Diesel conditioner in the Ruston some years ago.

The results were disappointing and she has smoked more ever since.

I guess it cleared out any accumulations here and there which were probably helping everything seal and seat nicely!

 

Hi,

 

I have been following this problem with interest.

 

Studying the 'Operating and Maintenance' Instructions for Gardner engines (covering the LW series,) page 20 - (dealing with fuel oil specifications) states that 'the best fuel is one having the minimum sulphur content and possessing the highest ignition quality. Fuels having a low sulphur content are usually of poor ignition quality'.

 

It is an intersting article which also suggests a fuel additive may be used to overcome this problem and closes with para 7.3 suggesting that up to a maximum of 1% lubricating oil (this can be used engine oil) may be added to fuel, and if paraffin is used as fuel the addition of lubricating oil is desirable.

 

Presumably Gardners fitted the seals and injection pumps of the type now used when the engines were built and had considered the problems the owners of vintage engines now possibly face - or think they face.

 

I would be interested to learn of the problems encountered with brasswork and fuels mentioned earlier.

 

Leo

[Timleech]

Hi,

 

I have been following this problem with interest.

 

Studying the 'Operating and Maintenance' Instructions for Gardner engines (covering the LW series,) page 20 - (dealing with fuel oil specifications) states that 'the best fuel is one having the minimum sulphur content and possessing the highest ignition quality. Fuels having a low sulphur content are usually of poor ignition quality'.

 

It is an intersting article which also suggests a fuel additive may be used to overcome this problem and closes with para 7.3 suggesting that up to a maximum of 1% lubricating oil (this can be used engine oil) may be added to fuel, and if paraffin is used as fuel the addition of lubricating oil is desirable.

 

Presumably Gardners fitted the seals and injection pumps of the type now used when the engines were built and had considered the problems the owners of vintage engines now possibly face - or think they face.

 

I would be interested to learn of the problems encountered with brasswork and fuels mentioned earlier.

 

Leo

 

I can't see low sulphur causing issues with brass components, in fact the opposite. Bio additives may be another matter, not qualified to comment on that.

I can't think of any seals on typical Gardner injection equipment which could be vulnerable, that fear may be more applicable to slightly later designs?

 

Tim