Original WW2 period RAF aero Engine Oil Sample Required

^^Ouch! Looks expensive…. 🙁

I think you need to factor in the fact that a lot of these engines “sit around” for extended periods and display work is usually short duration at higher power settings. Lack of use, especially when engines are not “pickled”, “kills” engines just as much as constant use.

I can vouch for that!![ATTACH=CONFIG]220558[/ATTACH]

I think you need to factor in the fact that a lot of these engines “sit around” for extended periods and display work is usually short duration at higher power settings. Lack of use, especially when engines are not “pickled”, “kills” engines just as much as constant use.

This accelerated wear which components are suffering the most?

Is the engine built to exactly the same standard as a 1940 engine or closer tollerances with new engine oil of today which is thinner?

Do the cylinder heads have harden valve seats?

Thanks pp.

Beaufighter, a delight to read this information. Flowers of sulphur. I can almost see a Shell chemist holding vial up to the light, a tear forming in his eye !
I would dearly love you to put this type of information down on paper. What might seem self evident to you might be priceless in 25 years time. I am very interested in building an understanding and documenting the technical information around historic aeroplane technology. Perhaps I can PM and start a conversation on this ?

Diverting off to talk Fiat A-74 and consume some pasta and red wine, will resume on return.

Off on another tangent Ray Hannah commented that the ground crew started the Sabre, wiped the oil off the windscreen then handed over to the pilot.

In real cold weather all aero engines required either oil dilution or pre-heating to prevent “coring” of the oil coolers.

I believe that the same as the radials, that the Napier Sabre engine with sleeve valves, also required a detergent type oil – there was many a story of preheating an engine during the early cold dark mornings to maintain the fluidity of the oils prior to starting the H24 engine. Perhaps the viscosity was higher for them too? Different spec oils for different engines. This is a very interesting topic.

Flowers of sulphur

“Tests have shown that a lubricant consisting of flowers of sulphur suspended in lanolin and reduced to a suitable consistency with castor oil practically eliminates fretting on con-rods. To be used on new production and repairs.” That is just one of many tricks RR had up their sleeve, who does it now?[/QUOTE]

Beaufighter, a delight to read this information. Flowers of sulphur. I can almost see a Shell chemist holding vial up to the light, a tear forming in his eye !
I would dearly love you to put this type of information down on paper. What might seem self evident to you might be priceless in 25 years time. I am very interested in building an understanding and documenting the technical information around historic aeroplane technology. Perhaps I can PM and start a conversation on this ?

Another gut instinct is that oils ain’t oils : Just like fuels have changed so Persian crude is different to North Sea crude and refining techniques in 2013 are different to those of 1941. Further, modern engines are designed to run on sun dried tomato and pesto type oils while old engines were designed to run on porridge type oils. Mix in decaying metallurgy with expensive, fancy pants oil decanted from a Ferrari and you get wear, maybe.

There are some great articles in late 1920’s Aircraft Engineering debating the move from accepted caster oil based lubricants to new fangled mineral based oils, which everybody said ‘would not work’. In delightful irony the times call for a return look at vegetable oil based lubricants as a carbon neutral alternative !

Recently I got some wartime BBC recordings of aircraft. What amazed me about the sounds of 70 years ago was the speed of the aircraft. They sounded nothing like what you hear at an airshow today. These were 20 year old pilots putting the throttle up against the stop. The engines were working. Perhaps the modern anxiety about not blowing the conrod out the side of an engine worth the price of a holiday house in Tuscany means that the engines are not being given a chance to clear their throats, residues are accumulating, uneven heating (hot-cold,hot,cold,hot,cold not hot,hot,hot,hot, cold) is happening and oils that look like a Bernie Ecclestone blonde instead of a fishwife are destroying the Mo-ers, as Arfur Daly would say….. Now that I think about Daly Motors, I’m off for a pint.

I’ve got some pristine oil. It came from the intact propeller piston/cylinder from a de-H prop which was attached to a Merlin III engine from a Spitfire.

The engine only came back from the MU after overhaul around two weeks before the crash so this could have been its first flight. It crashed in November 1940.

PM me with your details.

Anon.

I would concur with powerandpassion Aeroshell hand book statements. Immediately engine oil is used it becomes contaminated by combustion products such as sulphur, water and tetra ethyl lead. (used to increase the octane rating of fuels) The oil used in the Merlin was a mineral oil, in my experience OM270 and 370 depending on the environment. Detergent oils OMD270 were used in the fifties in the large radial engines. When I joined BBMF in 1978 we used OM270 on both Merlin and Griffon engines whilst the Chipmunk used OMD270. One had to be very careful not to re-oil the big engines by mistake with the detergent oil.
As far as I am aware no tests have been carried out using AD100 oil, (ashless dispersant), on Merlins, at TFC we continued to use straight 100.

When TEL was banned and the fuel went from Avgas 115/145 and 100/130 to 100LL (low lead) there were initial reports of damage to valve seats but I think this was negated by max. power being kept below +12 lbs. boost.

One must also consider the build of the engine when talking of wear and tear. Rolls Royce issued a technical note in late 1945 about the assembly of forked con-rods.
“Tests have shown that a lubricant consisting of flowers of sulphur suspended in lanolin and reduced to a suitable consistency with castor oil practically eliminates fretting on con-rods. To be used on new production and repairs.” That is just one of many tricks RR had up their sleeve, who does it now?

Oils ain’t oils

A sample of genuine period engine oil from, say, a RR Merlin of the WW2 period is required for scientific analysis by oil manufacturers and I am posting this request on behalf of a UK-based aircraft restoration and operating company.

Does anyone ‘out there’ have any uncontaminated engine oil that is guaranteed from an early wartime British aircraft (ideally a Merlin). This is required for analysis purposes as Merlins are currently suffering a lot of accelerated wear and there is a question about how different – if at all – modern oils are and whether they are relevant to a Merlin; of course, it could be how they are operated and that this continues to be a source of potential problems. About 50 – 100cc would be perfect for our requirements and I know that such samples have routinely been found in crash recovered engine blocks.

Aeroshell handbook July 1945, reprint Sept 1946 :
“Specification tests alone are insufficient to predict with certainty the suitability of an engine oil, only by thorough investigation as carried out by Shell can its satisfactory performance be determined…For British engines, with few exceptions, Aeroshell 100 is recommended…the use of detergent doped oil is not yet generally acceptable to all engine manufacturers for various reasons…in some engine types detergent dopes may give rise to combustion chamber deposits. This has occurred with Rolls Royce engines, and for that reason detergent doped oils are not at present approved for any of the Rolls engines.”

A Petroleum Handbook Royal Dutch Shell 1938 :
“water cooled aero engines are lubricated with exactly the same type of oil as high class motor car engines”

Few clues in there. Maybe the metallurgy is not supporting longevity, ie intergranular corrosion of steel alloys over 70 years is altering the wear characteristics of engine components. If your teeth go yellow in time so will your original Merlin rockers. Perhaps modern oils are in fact compensating for this with higher performance, and the use of old style oils will exacerbate wear. Need to get a metallurgist, an oil chemist and an engine mechanic in the same room and send in a pizza. Maybe they might come out and say its time to manufacture new engine components using modern metallurgy supported by modern lubrication systems.

Hi Andy, we have a sample from the oil scavenge pump from Halifax II JD150 if that helps, how much do you need?