Sir John Valentine Carden survives.

Napier must know more orders are very likely and they could be large orders. The temptation to cut their losses on the Sabre and just crank out Lion's, either petrol or diesel, must be very high. The could also possibly be looking at variations of the Lion for other uses, thinks like a V8 and V6 derived from it as well as a flat 4 could all be very useful and good sellers. The impact on aircraft engine production could be massive but I really don't want to derail the thread talking about it.
I'm fairly certain Napier were incapable of cranking out any engine in decent quantities, least of all the Lion which was a handcrafted beast even by the standards of bespoke engines. In the pursuit of making it the lightest possible engine every component had been reduced to the minimum, which meant none of them were interchangeable. The three cylinder blocks were all different slightly different sizes, the bolts slightly different lengths, that sort of thing.

For an engine designed without compromise for maximum performance and minimum weight and that was hand built by craftsmen, that was fine. But for volume production when skilled labour is at a premium it is a disaster. I can also confidently predict the logistics troops in the RAC coming to dislike it due to the shear number of similar but very slightly different spares that will be required to support and repair a Lion in the field.
 
So I came across this in P M Knight's A13 Mk I & Mk II Cruiser Tanks A Technical History. Black Prince Publications 2019 page 105-6:

I'm not entirely sure that answers your question. It also throws a negative light on what I had taken to be Vickers 2-pdr as the pompom, which was accepted and used by the Navy. Perhaps the Latvian tank used this rejected 2-pdr and my original understanding of Carden's "M/C gun" is wrong.
Earlier in the book (page 3), Clarke is senior military member of the Ordnance Committee. It talks about the race between the increasing penetrative ability of anti-tank weapons and the corresponding increase in the armour thickness needed to defeat them. Martel considered that this was a race that the anti-tank gunwas always going to win, and in this respect his thoughts were completely in accord with those of EMC Clarke at Woolwich, "who had vociferously argued against the development of Infantry tanks. Both men were also of the belief that the best protection for a tank was therefore speed and mobility." All this was in the context of the design of the A9 and A10 by Carden and Vickers, which were too slow, and increasing the armour of the A10 wouldn't therefore help as it slowed the tank. TBH there is probably more to it than all that but Knight's book is excellent, but suffers from having no index, so I'm having to scan and skim to find what I've noted as interesting/useful.
I read a slightly different take on this where Clarke's vitriol was aimed at the 2 per and Vickers was guilty by association. The article implied that Clarke believed the 2 pdr was an inadequate weapon (possibly because of his artillery background and the feeble HE shell). He was heavily involved in the development of the new 6 pdr so possibly will have a fit at Carden's 75 mm solution. But Carden could maybe get him onside by emphasising the space the Valiant has for his new project.
 
I'm fairly certain Napier were incapable of cranking out any engine in decent quantities, least of all the Lion which was a handcrafted beast even by the standards of bespoke engines. In the pursuit of making it the lightest possible engine every component had been reduced to the minimum, which meant none of them were interchangeable. The three cylinder blocks were all different slightly different sizes, the bolts slightly different lengths, that sort of thing.

For an engine designed without compromise for maximum performance and minimum weight and that was hand built by craftsmen, that was fine. But for volume production when skilled labour is at a premium it is a disaster. I can also confidently predict the logistics troops in the RAC coming to dislike it due to the shear number of similar but very slightly different spares that will be required to support and repair a Lion in the field.

Well that complicates things slightly.
I always kind of felt a modified Lion might be developed and this makes it a necessity. Perhaps a look by Ford as well so they can adjust the drawings to ease mass production like they did with the merlin.
 
Well that complicates things slightly.
I always kind of felt a modified Lion might be developed and this makes it a necessity. Perhaps a look by Ford as well so they can adjust the drawings to ease mass production like they did with the merlin.
Out of all the companies, Ford does indeed look like the winner on this. Dagenham has a separate production line for engines after all.
 
I can see a logical chain of events surrounding the need for greater numbers of Lions, both Petrol and Diesel:
  1. The ballon goes up, tank orders go up by an order of magnitude.
  2. Planners realise current stocks of Napier Lions will run out worryingly soon
  3. Napier receives contract to mass produce more Lions. Their projected delivery rates cause a ruckus, especially when they fail to meet them.
  4. Ways of increasing supply of tank engines is sought.
    1. A mass production partner is sought to increase supply.
      1. Nuffield? They’ll argue for substituting Liberties instead.​
      2. Ford?​
      3. Some other?​
    2. A replacement engine is sought in the UK​
    3. A replacement engine is sought in USA​
 
What was the issue with the Liberty engine?
Old engine ( with even older tech ) being pushed to its limits and beyond so it broke , a lot. From memory it had major cooling issues and separate cylinders to the crankcase. It also maxed out around 340hp so no good for 20 ton+ tanks.
 
Would the Napier Culverin be able to be adapted to being a bit smaller? Or we go back to the Thornycroft RY12?

Clulverin would probably be a stretch. It's dimensions would likely make fitting it in an issue anyway.
Not sure about the thornycroft but likely same issue.

I always assumed that the Lion would get some work anyway. It would likely need more power etc in the future. Getting Ford involved in manufacturing would be ideal.
1, you have a company that can produce the volume of engines needed.
2, they will be able to refine the design to ease mass production.
3, any potential derivative engines will be simpler that way.
4, Britain has seen Ford get engine mass production sorted.
5, when it comes to getting more power down the line Ford will be able to adapt production quickly.
 
Old engine ( with even older tech ) being pushed to its limits and beyond so it broke , a lot. From memory it had major cooling issues and separate cylinders to the crankcase. It also maxed out around 340hp so no good for 20 ton+ tanks.
It also had a chain drive which drained off I think it was 15% of the output!
 
Well that complicates things slightly.
I always kind of felt a modified Lion might be developed and this makes it a necessity. Perhaps a look by Ford as well so they can adjust the drawings to ease mass production like they did with the merlin.
The Merlin didn't need changing for mass production, it just needed all the details added on to the drawings. Simple example I read was hoses, Rolls Royce's drawings just said "3/8' high pressure hose from Point A to Point B", it was left to the fitters to work out how long the hose was, clips, fastenings, etc. Which works with a skilled workforce that knows all the company standard details, but Ford had to measure it out, specify connectors, fixings, all from scratch, then write out a procedure than an untrained workforce could follow. Then multiply it up by almost every ancillary detail on the engine and you can see why Ford took a year to get ready for mass production.

The Lion does need changing for mass production and fundamentally so. Easy example each cylinder was fabricated from 28 pieces that had to be welded together, which meant it was very light and strong but is obviously fiddly to build. If you change that for a 'conventional' cylinder it will be heavier and larger. And every element of the engine is like that, the USAAC reviewed a Lion in the 1920s and were very impressed at the power-to-weight and compactness, but concluded it was fundamentally unsuitable for 'American' production methods because it was just too complicated.

There is also the point the Lion was designed in 1916, it was an incredibly advanced engine for it's time but it is probably about as developed as it can be at this point. You can nail a turbocharger on it I suppose, that was done for some of the race spec engines and it is a good match for a notional Diesel-Lion, but there is not much more you can squeeze out of the design in terms of RPM or compression, that work has already been done.

Napier Culverin
Culverin was twice as heavy and 50% taller, though it would have more power, 800hp to 600hp in an RAF spec Lion XI (I'm assuming both get downrated for tank use, but the advantage will be similar). It was also designed for an external compressed air-starter, which is never going to work on a tank so it'll need chunky batteries and an electric starter, further increasing the weight. You could use it, but it will not be a one for one swap, you will need to seriously redesign the tank to make it fit.
 
Well that complicates things slightly.
I always kind of felt a modified Lion might be developed and this makes it a necessity. Perhaps a look by Ford as well so they can adjust the drawings to ease mass production like they did with the merlin.
Getting the US involved in any UK engine is for the better. What Packard did to the Merlin was amazing.
Unlike the UK, the US did not want fitters with a vise and a bunch of files anywhere in the manufacturing process.
If it didn't pass the GO/No GO gauges it was rejected
Too many rejections, and the line process would be examined and changed
 
It was also designed for an external compressed air-starter, which is never going to work on a tank
It's possible for air start for tank engines, Soviets used it for the V2 on T-34s.
Air tanks don't have cold soak issues like batteries
1605968462432.jpeg
Note air bottles
 
, that was done for some of the race spec engines and it is a good match for a notional Diesel-Lion, but there is not much more you can squeeze out of the design in terms of RPM or compression, that work has already been done.
going from2400 for standard engine to 3600 rpm is huge for large engines like this.
Dynamic balance was still pure voodoo when the engine was designed, and it was empirical testing that got it to where the race engines could run at that speed without destroying themselves, and then it was a matter of paying very close attention to the weight of every reciprocating part
 
As I understand previous posts, it's not guaranteed that the Lion can even handle being redesigned for proper mass production, and regardless it's such an old design that you're probably better off starting from scratch. Assuming that Napier and Vickers realized this once the war starts in September, the current stocks of Lions should be enough until about 1941 accounting for the production lag time for the Valiant. So they have several months to over a year to find or develop a suitable replacement for future production.

Ford is certainly a good option but if I recall they outright refused to make the Merlin under license OTL and the British didn't adop the GAA, which won't be available until 1943 anyway.
 
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