No Merlin, what are the alternatives?

[fastmongrel]

One of the reasons Rolls-Royce developed the Merlin, starting in 1932, was a perceived need for an engine to replace the Kestrel

The replacement for the Kestrel was the Peregrine. The Merlin was iirc originally conceived for aircraft like the Battle and the Peregrine was to be the fighter engine until fighter requirements grew and more power was needed.

 

[fastmongrel]

Yeah...I still haven't finished mine!

I have the rough outline down on paper in the form of dates and places but if I am to do it properly I would need to do lots of research. Basically its the British Purchasing Commision seeing the plans for the B 29 in 1940 and persuading Boeing to design the engine firewalls as Quick Engine change module capable. Then Canadian Vickers building a plant to build the Super Vulture with help from RR who send Stewart Tresillian and a small team from Derby to work with the best engineers Canada has on the development of the Merlin piston sized 3 stage supercharged engine. As a joint USAAF/RCAF/RAF project the B 29 gets into service earlier and an RCAF sqn has the honour of the 1st mission dropping a Tallboy on Berlin narrowly missing the Charlie Chaplin impersonator just as he is doing one of his radio rants.

 

[Dogwalker]

imagine the history books replete with references to how the Spitfire and Hurricane, both powered by that marvellous Buzzard engine, won the Battle of Britain.

When the name makes the difference... But perhaps, for the sake of posterity, they would reference to how the Spitfire and Hurricane, both powered by the marvellous "H" engine, won the Battle of Britain.

 

[wuzak]

No, surely it would be referenced as R?

Secured the Schneider Trophy for Britain for eternity, set the world air speed record (again, obviously a full blown R would have been stuck in the Spitfire for such an attempt), set the water speed record, the land speed record and won the Battle of Britain!

 

[Balljoint]

Back to the V-1710, wasn't the BoB fought at altitudes more fitted to its capabilities? I've found 15,000' as a common mentioned bombing altitude –though of course tactics are subject to change.

It would seem the main difference between the Allison and Merlin is heritage and development. The Kestrel Schneider Cup experience builds bigger muscles than airship use. While no small matter, the Allison shortcoming was super/turbo charging. Sadly, this was a matter of will rather than technology. With no Merlin, it would have been entirely feasible to expedite a high altitude Allison much earlier.

Finally, the fact that the Merlin powered so many planes is in some instances more a result of no more suitable alternative. Had the Hercules, or another radial, been available earlier, the Lanc probably wouldn't have used the Merlin.

 

[Shortround6]

Back to the V-1710, wasn't the BoB fought at altitudes more fitted to its capabilities?

While no small matter, the Allison shortcoming was super/turbo charging. Sadly, this was a matter of will rather than technology. With no Merlin, it would have been entirely feasible to expedite a high altitude Allison much earlier.

Unfortunately you can have all the will in the world but if you don't have the technology to back it up you aren't going very far.

While the bombers may have been coming in at 15-18,000ft the 109s were often coming in much higher. Getting bounced from above is NOT a good way to intercept bombers.

The world in general didn't have very good superchargers in early-mid 30s because the fuel in use (80-87) simple wouldn't tolerate very high boost pressures. In the US ALL superchargers were designed by ONE company (General Electric) until around 1936-37 when both P W and Wright, getting fed up with the GE supplied designs STARTED working on their own. It took several years for this to start to pay off. Allison had been making parts of GE superchargers under sub-contract as part of their engine related work, they sure weren't making ANY money on the V-1710 until 1939.

A small part of Hookers claim to fame was not only did he design the Merlin XX/45 and 60/61 superchargers but he discovered that some of the basic formulas for supercharger design were WRONG in the text books. While somebody else might have discovered it with no Merlin and no Hooker it it going to take a lot more than a snap of the fingers to "expedite a high altitude Allison much earlier".

Rolls Royce made about 1/2 the number of "R" racing engines during the 30s as Allison made V-1710s from 1930 to Jan 1939 let alone other engines.

The Allison was a good basic engine but the Allison company didn't have the number of people or the experience to do much more than they did.

Lets all remember that there were ONLY TWO companies beside Allison to get a two stage mechanically supercharged engine into large scale production ( at least several hundred made) during WW II, Rolls Royce and P&W. Bristol didn't do it, Napier didn't do it, Wright didn't didn't do it, Daimler Benz didn't do it and neither did Junkers or BMW. No Japanese company did it. No Italian company.

No will or it isn't quite as easy as it seems?

 

[Piper106]

The Buzzard / R was substantually the same displacement (2240 cubic inches) as the DB 601 (2070 cubic inches) and the Hispano Suiza 12Y / 12Z engines (2200 cubic inches) and rpm potential. History tells us that two teams working from about the same potential, the Damler Benz team turned the DB 601 into a great fighter engine, and while Hispano Suiza was only able to come up with a second class fighter engine. In this alternate history, if Rolls Royce engine development is as un-inspired as that at Hispano Suiza and RAF command structure as un-inspired as the French, German would have been the primary language taught in British schools by the mid 1940s.

 

[Balljoint]

Unfortunately you can have all the will in the world but if you don't have the technology to back it up you aren't going very far.

While the bombers may have been coming in at 15-18,000ft the 109s were often coming in much higher. Getting bounced from above is NOT a good way to intercept bombers.

The world in general didn't have very good superchargers in early-mid 30s because the fuel in use (80-87) simple wouldn't tolerate very high boost pressures. In the US ALL superchargers were designed by ONE company (General Electric) until around 1936-37 when both P W and Wright, getting fed up with the GE supplied designs STARTED working on their own. It took several years for this to start to pay off. Allison had been making parts of GE superchargers under sub-contract as part of their engine related work, they sure weren't making ANY money on the V-1710 until 1939.

A small part of Hookers claim to fame was not only did he design the Merlin XX/45 and 60/61 superchargers but he discovered that some of the basic formulas for supercharger design were WRONG in the text books. While somebody else might have discovered it with no Merlin and no Hooker it it going to take a lot more than a snap of the fingers to "expedite a high altitude Allison much earlier".

Rolls Royce made about 1/2 the number of "R" racing engines during the 30s as Allison made V-1710s from 1930 to Jan 1939 let alone other engines.

The Allison was a good basic engine but the Allison company didn't have the number of people or the experience to do much more than they did.

Lets all remember that there were ONLY TWO companies beside Allison to get a two stage mechanically supercharged engine into large scale production ( at least several hundred made) during WW II, Rolls Royce and P&W. Bristol didn't do it, Napier didn't do it, Wright didn't didn't do it, Daimler Benz didn't do it and neither did Junkers or BMW. No Japanese company did it. No Italian company.

No will or it isn't quite as easy as it seems?

CobberKane's thread is probably the better format to delve into this. But my point is that radial engines had reasonable good boosting. Allison was a rather small operation and got little support for a high altitude engine. Sanford Moss got much of the basic work rolling and, with interest from the airlines, had the workable radial engines. Great Britain better saw the need for a high altitude, liquid cooled engine and, like the P-51, might have contracted the work to the US had the Merlin not been available. All what if.

The Allison suffered from brain-fade problems such as flame arresters. And the AAF really didn't need high altitude escorts since the bombers could look after themselves. Sans the Merlin, the Allison was the best bones available for a liquid-cooled, high altitude engine. But of course there were other engines and other ways to skin the cat.

 

[Aozora]

CobberKane's thread is probably the better format to delve into this. But my point is that radial engines had reasonable good boosting. Allison was a rather small operation and got little support for a high altitude engine. Sanford Moss got much of the basic work rolling and, with interest from the airlines, had the workable radial engines. Great Britain better saw the need for a high altitude, liquid cooled engine and, like the P-51, might have contracted the work to the US had the Merlin not been available. All what if.

The Allison suffered from brain-fade problems such as flame arresters. And the AAF really didn't need high altitude escorts since the bombers could look after themselves. Sans the Merlin, the Allison was the best bones available for a liquid-cooled, high altitude engine. But of course there were other engines and other ways to skin the cat.

In lieu of an engine in the Merlin's power and size range its always possible that the British would have negotiated with Allison to license build the V-1710; the company most likely to build the Allison would be Rolls-Royce (this isn't forgetting Rolls-Royce later bought Allison off GM). It's then not a big leap to consider the possibility of Rolls-Royce, with all their experience (rolls-royce kestrel | 1935 | 0666 | Flight Archive ), adapting their superchargers to the Allison. Not forgetting the Americans started using 100 Octane fuel by the late 1930s and Britain adopted the fuel soon after, such that all of Fighter Command's front line aircraft were using it before the Battle of France.

Finally, the two-stage, two-speed R-R supercharger was adapted from a French Farman design which had been built in 1935 wiley post | 1935 | 1022 | Flight Archive

 

[Shortround6]

The Buzzard / R was substantually the same displacement (2240 cubic inches) as the DB 601 (2070 cubic inches) and the Hispano Suiza 12Y / 12Z engines (2200 cubic inches) and rpm potential. History tells us that two teams working from about the same potential, the Damler Benz team turned the DB 601 into a great fighter engine, and while Hispano Suiza was only able to come up with a second class fighter engine. In this alternate history, if Rolls Royce engine development is as un-inspired as that at Hispano Suiza and RAF command structure as un-inspired as the French, German would have been the primary language taught in British schools by the mid 1940s.

The two engines mentioned were NOT the same potential. The Hispano was several hundred pounds lighter than the DB 600/601 engine which limited both the RPM and Boost pressures that could be used. Please look at the Russian V-105 engine for "development" of the Hispano. Beefed up crankshaft, beefed up block, changed cylinder heads with 3 valves instead of 2. Unfortunately they kept both the poor porting and SIX blow though carburetors of the Hispano. Using better fuel than the Hispano had they fell short of 1300hp and that was only achieved bu using superchargers optimized for low level work.
Post War Hispanos ( in France, Spain and Switzerland) gained a LOT of weight, fuel injection, multi valve heads, 100-130 octane fuel and got all the way to 1600-1700hp for all their displacement.

Rolls-Royce had built 5 different V-12 engines (and two more variations) before starting work on the Merlin. Plus the car business. The Rolls management had also hired R.J. Rowledge who had Designed the Napier Lion.

 

[Piper106]

The two engines mentioned were NOT the same potential. The Hispano was several hundred pounds lighter than the DB 600/601 engine which limited both the RPM and Boost pressures that could be used. Please look at the Russian V-105 engine for "development" of the Hispano. Beefed up crankshaft, beefed up block, changed cylinder heads with 3 valves instead of 2. Unfortunately they kept both the poor porting and SIX blow though carburetors of the Hispano. Using better fuel than the Hispano had they fell short of 1300hp and that was only achieved bu using superchargers optimized for low level work.
Post War Hispanos ( in France, Spain and Switzerland) gained a LOT of weight, fuel injection, multi valve heads, 100-130 octane fuel and got all the way to 1600-1700hp for all their displacement. Rolls-Royce had built 5 different V-12 engines (and two more variations) before starting work on the Merlin. Plus the car business. The Rolls management had also hired R.J. Rowledge who had Designed the Napier Lion.

I should have made if more clear that I was speaking more of the whole Hispano Suiza development process than specifically the 12Y engine. Agreed, the 12Y had run out of growth around 1000 HP. HS needed to have gone to the beefed up 4 valve per cylinder 12Z design 2 years or even 3 years earlier than they did to stay in the 'race'. To further emphasize the point, the same 150 x 170 mm size cylinders as the 12Y and the 12Z was eventually used by Hispano Suiza in their 12B engine which was in the 2000+ HP class and roughly equal with the RR Griffon. The problem is that Hispano Suiza didn't complete development of the 12B until the late 1940s. By then no one cared.

It was common knowlege in 1940 that Hispano Suiza was working on an engine called the 12Z which was a higher power development of their 12Y. I have read that the French Hispano Suiza plant was loaded with communists / communist sympathisers during that period. Further, engineers/managers in the Hispano Suiza development team would have been susceptable to 'persuasion' by Soviet agents. Taking all that into consideration I am surprised that Klimov did not have a full set of 12Z plans to work from rather then having to continue 'tweeking' the obsolete 12Y design.