Just how rare are Merlin engines?

Look up the history of the RB-51 😉

http://51-factory.com/inventory.htm

Likewise, the vast majority are Packard V1650S.

DAI

Something doesn’t look right about the Griffon. Maybe we’ll just put some thicker oil in it….

Look up the history of the RB-51 😉

Heaven on a stick

& a Griffon…(Red Baron P51)

When I was five I dreamt of working in a jelly bean factory.
When I was 25 I dreamt of being lassoed by Wonder Woman, toyed with by Cat Woman.
Now that I look like Homer Simpson I dream of a warehouse of V12s…

Thanks for sharing ! How much for the lot ? Something doesn’t look right about the Griffon. Maybe we’ll just put some thicker oil in it….

& some Allisons…

& a Griffon…(Red Baron P51)

According to the AEHS website, author Dave Birch has been collecting the serial numbers of surviving Merlins for an upcomming RRHT book. It will be interesting to see what his final tally is.
http://www.enginehistory.org/

Did any of the tooling or drawings survive from the Lidcombe plant in Australia?

Not neccesarily. CNC machined billet steel cranks can be stronger because thay can be made at room temperature from stronger alloys than those which are able to be forged. This has become standard practice for many high end racing engines today.

I wonder if Continental Motors still has drawings for the Merlin.

I did make the point that you should ignore all the car stuff when looking at an engine the size of a Merlin. The dynamics of large engines are entirely different to a modern high revving car engine, racing or not. Indeed V configuration racing engines often have a V angle that not ideal for even firing with std cranks, and have to use offset big ends.

.

I don’t understand the forging phobia on this thread.

Forging is a great process which has a good availability and has benefitted enormously from new technology. Eg complex forging dies can be easily made by 6 axis high speed machining, process modelling means you get right first time without die modification, press sizes are larger /more numerous than ever ( thanks to the closing period of the Cold War and the recent boom in civil aerospace), and low volume large components can be produced by the “Hand” forging process whereby the robot arm has replaced that of the human.

Yes you do have to do sample cut up’s/etches to proof the process, but this is bread and butter to the forging companies which I’ve dealt with. If you think cut ups are expensive I would suggest its peanuts compared to the cost of recert of the part.

Just because the niche racing is approaching their crank manufacturing in one way doesn’t mean there’s a capability shortage.

Sometimes reality is not so grim

I suppose one way perspective is that whilst there are “new” authentic WWI aircraft being built, almost all of them include either original or modern components in some way – be it instruments, wheels, tyres, turnbuckles, bolts, engines, or whatever. To set up to make EVERYTHING that was being made across hundreds of different suppliers is unlikely to be viable for some considerable time, although some modern processes certainly do help.

A WW2 era engine is a microcosm of that – when one considers everything from the carburettor to the supercharger, to the accessories, it’s just not going to be economical, and there’s no point – a large number of those components can be reconditioned and are unlikely to be in short supply for the foreseeable future.

Powerandpassion absolutely nothing to apologise for, the thing that makes this forum zing is the discussion and counter arguments posted by other people and the ideas that come from it.
I believe a Company in the UK is making new cylinder heads for the Merlin now, but I could be wrong. My main point was the fact that to build a new engine complete such as the Merlin involves thousands of parts that would each need to go through the process and that would be seriously expensive for the returns, it’s not exactly a mass market for these engines. I realise as said that in NZ they have been knocking out WW1 engines for some of the latest projects, though to be fair a WW1 engine is not near as complex nor stressed anywhere near the last of the big piston engines, technology had moved on in leaps and bounds in a very short period of time before they were superseded by the Gas Turbine.

As a bit of an aside, apparently making the cores for casting Merlin blocks etc was too intricate and difficult a job for men so it was done by women – who became expert in the art. However, they did have to start as beginners so presumably such skills can be re-invented.

FAA approvals do necessarily mean they can be used on CAA permit aircraft.

Product liability….. releasing drawings and that part failing and causing deaths would come back up haunt you..

Take Rolls Royce as an example as they built the Merlin, they no longer produce piston engines, they have moved on, why on earth would a company as such release drawings for parts that are no longer made, for engines where their expertise no longer lies, where their core business isn’t, because as the Design Authority they would be culpable? If anything went wrong, it would open them up to future litigation. Remember in the scheme of things there would be no advantage to them, financial or otherwise, just lots of risk. And in this day, an age of bad publicity and the effect on a companies share price, you can totally understand it.

Hence why without the likes of Royce’s, Marshalls and BAe onboard as Design Authorities, the Vulcan would still be sitting at Bruntingthorpe, as one would imagine the CAA would have said no chance. I’m still suprised they got onboard as it must have been a risk for the companies.

TonyT,

I apologize for reacting viscerally to your post. It is not personal. I am a Dreamer. All your points are valid and grounded in reality. I have a friend who I debate with who calls reality the “Big R”. Our debates are never won. At a distance to any particular debate, I reflect that the Big R and Dreaming are wound around each other like a helix, in any healthy state of human affairs. If one is more preponderant over the other, bad things can happen. In respect of aviation there is no progress without Dreaming, and things don’t fly without the Big R.

I sense that in historical aviation there is a shrill, protesting element to the Big R. It resents Dreamers doing things that it can’t get a handle on and pigeon hole. It’s visceral urge is to shut things down. It’s like a lorry driver looking at an upturned truck of chickens squawking and scattering over the road.

Fundamentally things in historical aviation are driven by Dreamers, who turn scrap into angels, fanatics who grind, smash and shortcut their way to the top of impossible summits. If they don’t fly headlong over a cliff they eventually tire out the “Big R”, which begrudgingly accomodates them into an expanded version of Reality. So the Big R, which swore 40 years ago that a warbird would never fly, now tolerates this. In the end the simple fact that 70 year old engine spare parts supply cannot sustain the present reality will mean that the idea of remanufacture will have to be an unremarkable reality.

How could we get there ? Let’s accept that the taxpayer funded and sustained the aerospace industry as an intrinsic feature of the industry. Without the taxpayer the industry would have failed many times over. I am impressed, in going through libraries, how many publications were funded by old industrial conglemerates, in a tacit acknowledgment of mutuality. These days it is called being a good corporate citizen. I can understand that it is not the job of a harassed manager in a modern corporation in the midst of a global recession to accomodate requests for archived engineering information and the unrenumerative supervision of some Dreamer in a garage working on an antique product. Perhaps the Dreamers should become more sophisticated in their approach? Use the tangible accounting factor of ‘good corporate citizenship’ to propose a transaction which is digestible.

One thing to do is to setup a non profit, incorporated entity to take anything to do with antique products off corporate balance sheet, off products liability exposure and off the current budget. At the same time set up a constitution for the non profit, incorporated entity that captures the essence of what it is for : making children see and hear V12s flying through the air, to be proud of their country and perhaps want to become engineers. No doubt such an entity would want products liability insurance and professional indemnity insurance for its officers. These things would cost money. Therefore it would have to charge cost recovery to any party wanting to use its archives, conditional on accepting inspection of works completed in accordance with archived procedures, again at cost. In other words a mini CAA, made up of semi retired folk, skilled in the art, excited more by a participation than a paypacket.

Properly constituted, such an entity could act as a circuit breaker between a modern conglomerate, modern inspection and approval authorities and Dreamers.

Another aspect is revitalising a collectivist ethic. As a complex mechanism aircraft and engines were products of original collectivisation, between metallurgists, metal suppliers, forges, casters, cork gasket folk, magneto folk, bakelite magneto distributor cover folk, platinum depositors on distributor breaker point folk, breaker point spring folk etc, etc. In some way responsible Dreamers must become collectivist. If you know you need 20 distributor breaker points, make 1000, get them approved by the previously described non profit incorporated entity, then make them available to the wider community. For the sake of collectivism, fix the profit on cost at 30%, as the government fixed the profit originally. The advent of the internet makes it feasible for the cork manufacturer in Portugal to make 1,000 sets of rocker cover gaskets, the engine bearing manufacturer in Australia to make 1,000 sets of big end bearings, the crankshaft forge in India (!) to make 500 crankshaft blanks and the CNC machinist in the UK to finish 1,000 fuel pump gears and be on one database. Rather than one Dreamer make 500 individual pieces over 25 years, make 500 repetitions of one part in one year and buy/trade the other 499.

As I say I am a Dreamer !

My understanding with forging crankshafts is that the skillsets/experience to forge from billet as per original method is scarce. Theoretically a forged crankshaft may be stronger on paper but the skillset to work economical numbers of ‘accepts’ is not there, whereas CNC from a billet of proven, modern metallurgy gets a result. To say that there has been no progess in steel metallurgy, viz, alloy composition, may be correct, but this does a disservice to method of manufacture. In other words the capability to produce grain structures of predictable and superior characteristics is much improved (unless it is a chuck on a Chinese manufactured drill, when it may have asphalt road inclusions). It is not strength which is wanted, more predictablity.

I do like the old engineers, they were Dreamers :

“An important feature from the design aspect is that if it is desired to use material of different characteristics, or if new metals become available, no re-design is necessary-(in respect of tubing)-merley an alteration to the gauge of the tubing.”
from Air Annual of the British Empire 1933-4 -Hawker system of Construction pg 342

God Save the Queen ! God Save the Merlin ! Sigh for a Merlin !

Ah no! For a given grade of steel the forged process will always be stronger and more durable than the machined.

I was of the understanding that crankshafts were a unique case due to the large amount of dislocation required to get the material out to the crankpin and counterweight area and that machining a solid block of forged billet gives better results. Mind you I also believed my mother when she told me that frogs were green because they photosynthesised which turned out not to be true either.

one would doubt many companies have the facilities to do this at all

That doesn’t mean it isn’t possible. Like Stan Smith said, In little ole New Zealand The Vintage Aviator has contractors producing components and entire engines that have not existed since the Twenties and earlier.

I’m probably wrong, but I thought it was due to it not having been overseen by the CAA and different resins being used etc?

Not bringing the Mossie to the UK was about getting it there. Shipping the aircraft is an issue because of its one-piece wing. Rumour has it it’s up for sale…

Ah no! For a given grade of steel the forged process will always be stronger and more durable than the machined. Ref MMPDS (mil handbook 5)

As yet mankind has not invented a simple heat treat which can give you the directional grain refinement created by forging.

Comparing what materials have been used in automotive to aerospace is a red herring. Aero spec are typically 2-3 x stronger than those of auto. Sure some of the racing cars are upgrading to aero spec but if your already at aero specs you have no where to go

And finally steel technology reached it peak 50 years ago and has moved on little since. Eg
Boeing latest 787 steel landing gears legs are made from the same spec steel used in the B47 i.e 300M or triple melt 4340

Structurally the worst thing you can do is cast steel

If for example, you need a Beardmore Viper or a le Rhone, they make ’em all from scratch out here in Nevernever land. Refer The Vintage Aviator and Classic Aero Machining Service for further info.

Quite. More exactly
Oberursel http://thevintageaviator.co.nz/projects/oberursel-engine/oberursel-ur-ii-rotary-engine-build-history
Mercedes http://thevintageaviator.co.nz/projects/mercedes-engine/mercedes-engine-restoration

Gnome http://www.cams.net.nz/Gnome%20Remanufacture.html

We of course have a different regulatory regime here.

And an interview with Tony Wytenburg of Classic Aero Machining Service is included in this podcast done at Classic Fighters (Omaka) 2013.
http://www.cambridgeairforce.org.nz/WONZ_Show_Two.html#Ep_42_Classic_Fighters

Tony the strongest modern cranks are still forged.

Not neccesarily. CNC machined billet steel cranks can be stronger because thay can be made at room temperature from stronger alloys than those which are able to be forged. This has become standard practice for many high end racing engines today.

I wonder if Continental Motors still has drawings for the Merlin.

There was no technical issue with the Mosquito that prevented it coming here – it was only due to timing.

It used to be the case (and may still be) that there was no way of releasing a Merlin engine to service in the UK other than by the use of an American form 337. The majority of aircraft operating on a permit to fly have no original manufacturer support whatsoever, nor is it required. The Vulcan is an obvious exception. That said, it is necessary to demonstrate that they conform to the original type specification.

Bruce

I thought Aviation Jersey Ltd had the right from RR to supply spares and technical services for the Merlin and Meteor. If so, how far did the ‘technical services’ part of the deal extend?

If you were to look back at the original suppliers of consumable components in the Merlin, you may just be surprised at how many are still about still supplying pistons, rings, valves and bearings etc to all and sundry. It maybe that others have taken up the challenge of keeping the Merlin airworthy, but getting new parts is only a matter of will power and demand. There are no technical impediments. After all certain Merlin’s had been cleared to 30lbs boost late 44 early 45 giving about 2,200 hp on 150 fuel. Aside from the Reno racers who also use water injection to cool the intake air, it’s not as if those displaying at airshow really put the Merlin under that much stress and accelerated wear rates.

I thought Aviation Jersey Ltd had the right from RR to supply spares and technical services for the Merlin and Meteor. If so, how far did the ‘technical services’ part of the deal extend?