Merlin/Meteor parts interchangability?

Looks like a set of bearing shells for the main journals of the crankshaft.
I don’t know if they are interchangeable, but I wouldn’t be surprised.

I was told once they are not interchangeable but that was in the 80s I think when a Meteor engine was up for sale and I nearly bought one, it was said its a completely different engine, but obviously that was decades ago.

I know it can be a less than rewarding experience to re-open an old thread these days, but you never know, someone might be able to assist.

As part of the ongoing garage clearout which has a thread of its own…

https://www.key.aero/forum/historic-aviation/140142-more-treasures-from…

…these treasures have resurfaced.

Having made enquiries years ago, I was told that these are Rolls-Royce Meteor parts.  I just wondered of anyone can confirm this or perhaps point me at someone who might know?

I’m pretty sure my initial investigations were pre-internet days but I’ve tried searching by the R-R Part No. and have drawn a blank.

Any help much appreciated as always!

Excellent run down Pete thank you….:)

Somewhere near Leeds!

IN Leeds Brian…a fact I am reminded of when I have to cross the city every morning and evening when I battle the rush-hour!

The engine in question the Stuart refers to used a Meteor crankcase and blocks (blocks are visually the same as the Merlin, and on Meteor Mk Is they are Merlin)
The Merlin wheelcase will basically bolt straight on, but you need the generator outrigger drive on the crankcase, we did this by welding the rear mounting from a crashed crankcase and inserting an oil drain pipe for the generator drive. There is also a difference on the other side, but if it is a static then this could be left.
The reduction gear is a whole lot different. From the viewpoint of making a running engine, the aperture in the Meteor which takes the drive for the fan pulleys is conveniently on the centreline of the Merlin prop shaft, and slightly smaller diameter, so we were able to machine this out and it replicates the rear bearing housing, because this is part of the Meteor crankcase, all the rest of the rear casing, which we cast in order to make it as solid as possible, is only a partial support and partial housing, much of the strength coming from the crankcase and front cover, which is a Merlin item. You could probably mould that rear casing in fibreglass, or fabricate it in some way for a static.
The engine ran for many years without trouble, but eventually the front main bearing went, probably due to the distortion of welding the crankcase, although to be fair, it was ok when we originally put it together. It does still run, after Steve Kingman did a complete rebuild on it, but we haven`t attempted to do another, too much work and potentially unreliable, but thanls to Robin Byers welding abilities, it is indistinguishable from a Merlin to 99% of people who see it.

Pete

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Thanks Stuart..Yes somewhere in the endless gaps in my memory can recall Pete did such a job..PEEEEEEEEEEETEEEEEEEE where art though !! 🙂

Somewhere near Leeds!

Merlin Pete, shall be your guide Ross, as I believe he was involved in just such a conversion.

Thanks Stuart..Yes somewhere in the endless gaps in my memory can recall Pete did such a job..PEEEEEEEEEEETEEEEEEEE where art though !! 🙂

Not contributing much to the original question – but it might be of interest…..

In a previous existence I was a computer programmer working for the MOD on Defence Codification – the allocation of part numbers to UK & NATO military stores.

The unified system was brought into use because if a Royal Navy Landrover broke down outside an Army barracks, it couldn’t be fixed due to the fact that its parts had different stores reference numbers to the equivalent Army parts – a Navy ‘tire’ was a different part number to an Army ‘covers outer’ for example – even though they were exactly the same thing!!!!

Our instructors told us the story of how, during the Korean war, a squadron of USAF F-51 Mustangs was temporarily grounded due to a lack of spare parts for their Packard Merlin engines.

Little did they know that over the next hill was an Australian Army unit equipped with Comet tanks – powered by Meteor engines.

Had the stores reference number systems – or even the nomenclature of the parts – been the same, it was just possible that the F-51’s could have been made airworthy with parts from the army tanks.

And so the seeds were sown for what became the NATO standard codification system – with NATO Stock Numbers becoming universally accepted throughout the alliance.

It’s an apocryphal story – but with a hint of truth in it.

Ken

Merlin Pete, shall be your guide Ross, as I believe he was involved in just such a conversion.

Thanks mate..Maybe Ill design something like an adaptor plate to suit…Cheers 😉

I think your major stumbling block is going to be be the crankcase Ross. There is no way to bolt up the reduction gear or the accessory case/supercharger.

What would be the interchange process be to convert a meteor into a static Merlin 45.We already have a single stage supercharger and carb to suit..

You would not be able to use any meteor parts in an airworthy Merlin.
CAA regs would prohibit it.

Just a few parts as has been said already. Yes some of the pistons, though not most, had a higher 7:1 compression ratio, but all Meteor pistons, except possibly the Rolls-Royce built MkIs, were cast, not forged like the aero-engines. I have seen Merlin blocks used too, but they have all had dual coolant transfer ferrules on the exhaust side of the block, whereas the Merlin is only bored for single ones, so these blocks would not be suitable. Merlin connecting rods used in Meteors could be re used in aircraft if they don`t have that small hole drilled through the web, presumably done to mark them as unsuitable for airworthiness.
Some Meteor bearing shells have been re-plated and used in Merlins.
One thing which definitely isn`t useable are the camshafts, as the Meteor rotates the other way, this tends to apply to cranks as well, because cranks are ground in the direction of rotation, although Merlin cranks at std. size could have been fitted to Meteors.
The MkI engine used single piece blocks from Battle of Britain era Merlins and these can certainly be re-used.
I don`t know about two piece block liners on later Meteors being used on Merlins.
The Merlin camshaft is manufactured here in the UK as well. Rousch in the USA make a neat roller cam follower set up, but this isn`t CAA approved.

Pete

It is very possible the liners can be used 😉 and I would not be surprised if the cylinder blocks (or skirts) and some of the conrods are ex-Merlin stock. The Meteor conrods I remember were all shotpeened. Yes, Merlin cams are like rocking horse manure, mainly due to the design, compounded by the irregular use of the engines these days. This is the reason why most operators have some sort of pre-oiling system fitted to their machines. It only takes a couple of seconds whilst oil pressure is building up after start for a “dry” cam to be destroyed. Cams, amongst other things, are being produced as PMA’ed parts by Roush Aviation, for one example.
Anything is possible if you throw enough cash at the problem and you want it bad enough… 🙂

I have been told from a very reliable source that the cams are interchangeable. The cams have been removed from several Meteor engines to use in Merlins as Merlin cams are no longer available or is anyone able to ( inc Rolls Royce ) manufacture them. !!

Regards
Mark

I understood liners could be used? Certainly cylinder blocks are ‘the same’ as I have seen Buick cast blocks on Meteor, presumeably originally from Packard Merlin.

I’ve also had rods that were machined all over marked D30047 and others just forged finish, all in Meteor packaging.

Not many really. Some of the crankshafts were surplus Merlin stock and still had “D” numbers on them. Some of the seals, especially for the transfer of fluids between the head and cylinder skirts are the same. The cylinder liners are liners are longer, pistons higher compression and the crankcase obviously different on the Meteor. Probably a few other things, but I can’t remember off the top of my head right now.