For all the British vehicle experts/nuts

[jdmcm]

Gentlemen

As you can probably tell from recent posts we are ass deep in a Centurion tank at the moment, and one of the things that comes to mind is what are we going to use to maintain this thing oil wise...near as I can tell the Meteor calls for a straight non detergent 30W...but I am not close to convinced, so I thought I would ask the experts who have been running and maintaining these vehicles. Is there a cross reference that is reliable for UK specified oils North American equivalents? I was just reading a post today about a modern gear oil eating a fellow MLU members bronze bushings and it has put the fear of god (MOD?) in me. Any guidance or help would be appreciated.

Regards
John

[rob love]

There are plenty of charts giving the UK to NATO to North American specifications, but it won't be as simple as that. Oil specifications constantly change. You may have to look at what era your vehicle last ran, and on what oil was likely in there at that time.

Considerations include the detergent/non detergent criteria, and that oils are now different for diesel or gasoline. The removal of the zinc is a big one for flat tappet engines. With a lot of these older engines, either running diesel oil or else adding a ZDDP additive is likely necessary.

From my own experience, we changed from the straight weights to the multi weights pre 1980ish, and then went to the 15W40 on most of the fleets in the mid 80s, which we are still running for the most part.

[jdmcm]

Thanks Rob!

[maple_leaf_eh]

The biggest operator of Merlins in Canada is arguably Vintage Wings in Gatineau. If you contact Nick at the Cold War Collection he will introduce you to their maintainers. Kindred spirits like to help, but being presented as a friend will be better received. The Collection's principle and Vintage's principle share similar excitements from old equipment.

[jdmcm]

Thanks Terry, great idea


John

[Mike Cecil]

John,

Malcolm Towrie in Ontario has just worked his way through the same lubrication dilemma/problem before firing up the ORM's reconditioned Meteor Mk4B. He was assisted by communications with John Blackwell, ex-RAEME tech working on 169005's engine re-installation at Puckapunyal.

Maybe communicate with Malcolm in the first instance?

Best regards

Mike

[jdmcm]

Thanks Mike, I will contact Malcolm as well

Regards
John

[Malcolm Towrie]

John, after I responded to your PM, I found this post. I agree 100% with Rob Love. I think modern diesel multigrades are the way to go. We use Shell Rotella 15W40 because it is loaded with ZDDP which is an important anti-scuff additive that got taken out of modern automotive oils because it contaminated the cat. ZDDP protects the rubbing contact areas between flat tappet cams and lifters or overhead cams and rockers like the Meteor. When roller lifters became the norm in gas engines, ZDDP was quietly removed from the oil. It drove the engine rebuilders crazy because older engines with flat tappet cams would mysteriously wipe cam lobes after a few hundred miles. The oil manufacturers eventually admitted they had taken out the ZDDP. That's why there are so many ZDDP additives on the market now.

So an oil like Shell Rotella 15w40 suits the Meteor engine because the ZDDP protects the cam lobe to rocker contact surfaces, and the low viscosity of the oil when cold ensures oil gets pumped up quickly to the cams.

One concern i have with this oil is if you have been running a non-detergent oil for a long period, the strong detergents in Shell Rotella will start to dissolve the inevitable sludge built up throughout the engine, especially the oil pan. If the engine only has a bypass filter system, this is not good for the bearings.

Malcolm

[Grant Bowker]

Let me start by saying I have no specific knowledge of the Meteor or Merlin engines.
Have you considered talking with a tech rep at one of the oil companies about what their aviation divisions suggest for such an engine? (After all, that's what the Merlin was designed for.) Many of the horizontally opposed aero engines were designed in that era and are not much changed.

[jdmcm]

Thanks Malcolm I find your argument for modern Diesel engine oils makes a lot of sense. I was a big fan of Shell Rotela when I had my trucking company, I still use it today in the remaining tractors I have as well as my M813 5ton. Now since there is no drain on the oil sump tank, I guess several oil changes will be necessary to remove all the old oil. I know the meteor has two filters one on each scavenger pump, keeping these clean in the advent of the sludge beginning to creep through the system will be essential

John

[jdmcm]

I have spoken with a pilot friend who is in charge of several "Merlin" engines, the supercharged cousin of the meteor, he stated they use 100wt mineral oil in the Merlins, I assume due to the engine spending much more time at higher rpm's. Gonna be a smidge thick for the Centurion. I am definitely leaning toward the Shell Rotella 15w/40, now a guy needs to figure out the rest, transmission, differential, final drives etc.

[Grant Bowker]

Sorry, I had meant to put this link to Shell's aero piston engine oils in my last post https://www.shell.com/business-custo...oil/about.html
It looks to me as if their numbers are twice the SAE viscosity (e.g. AeroShell 100 is a SAE 50 oil).
In terms of RPM, compared to most modern gasoline engines the Merlin is low revving, limited to 3000 RPM (also compared to diesels in North American pickups, my Ford is limited to 4000 although I haven't taken it near that - no need and I don't want to listen to it at that speed). As a 27 litre engine 3000 should be enough for the Merlin....

[Lang]

John

As Grant says the Merlin uses W-100 or WD-100 (one straight and the other detergent).

Aircraft nomenclature is different to everybody else and aviation 100 is actually what we would call 50 weight. The two almost universal mineral oils used in aviation are WD-100 and WD-120 (either 50 or 60 grade normal description) The straight oil is used in new engines for a short period of run-in before going to the detergent oil.

I would hazard a guess that 20/50 would be a good modern selection.

Aviation equivalent synthetic oils are becoming more widespread now as well.

Here are the Kiwis at it.
https://www.youtube.com/watch?v=yaAoI50KZ9Y

Lang

[jdmcm]

That is a great explanation Lang, now the aircraft oils make more sense

Regards
John

[Robin Craig]

John and Malcolm,

are you saying that all modern produced of straight 30wt have no ZDDP in them? That is what I am gaining from this thread, perhaps I am missing something, wouldn't be the first time.

I am reading this with interest and learning.

[rob love]

Robin

The ZDDP has been removed, for the most part, with the last couple of specifications of gasoline engine rated oil. Here is a decent article on the service classification ratings. http://www.pqiamerica.com/Labels.htm
The ZDDP was dropped in the last couple specifications of oil, and will require additives. One option is the high mileage oils, which generally have more zinc.

The diesel rated oils have plenty of ZDDP, and are a good alternative to buying those little $10 bottles of additive. It is not just the expense, but even finding the stuff.

Personally, I have been going over to the Shell Rotella as well, especially the synthetic arctic grades. I don't know how I would have survived this last winter without it.

Back in the 80s, the oils I was familiar with had both diesel and gas ratings to them (ie SAE SF-CD). Now they seem to have split the diesels away from the gas oils.

End of the day, one must do some homework on oils for the older engines and in some cases, use older specification oil for older engines. You can still buy 30 weight with good levels of ZDDP, and you can likely buy 30 weight without appropriate levels. It all comes down to the rating. Pretty much goes for all the weights and multi weights of oil.

[Wayne Hingley]

Here are a couple of additive options. One is a ZDDP additive and the other is a substitute. I have not used either one of them yet, so I can’t make any claims.

[Robin Craig]

It is great when you discover that a trusted supplier doesn't know what they are talking about and supplies you a product that doesn't perform.

The information here was very useful, thankfully few miles have been driven so it looks like some oil changes are coming up soon.

Thank you all, its hard to admit you have been scuppered but there you have it.

[jdmcm]

Robin

any chance your oil filter adapter would allow the use of a spin on filter on the Meteor?

Regards
John

[Robin Craig]

John,

Very possibly might do, can you send me or post here pictures of the filter assembly from either the manual or from real life please. I currently have stock.

The head is the main part and what filter does it use?