Could you Put a Merlin in a Zero?

[AbitNutz]

I know, the whole idea on its surface sounds ridiculous, maybe deeper down as well. The A6M8 took the Zero to its max with the Kinsei engine at some 1500 hp. I suspect they were very small and short lived horses at that amount. Anyway, if true, it showed the airframe, at least that airframe, could handle over 1500 hp.
I know the Japanese made a couple of other terrific planes toward the end of the war, the Ki 100, the Ki 84, etc. But a dead nuts reliable liquid cooled, smooth as butter V12 surely is worth a look as replacement for a such a noble aircraft as the Mitsubishi Zero. Far better than being a transporter for a human bomb.

As for engine weight, I don't believe anybody. I've read the 2000 cubic inch DB 601 weighs less than the 1650 cubic inch Merlin. The difference in listed weight between the DB 605 and the Griffon is even worse. I think everybody weighed their engines in different states of dress and I don't think you can believe any of these weights.

I think it would have been a really beautiful if spartan looking plane. That's my delusion...

 

[Admiral Beez]

Per Wikipedia The Nakajima Sakae...

• Length: 1,600 mm (63 in)
• Diameter: 1,150 mm (45 in)
• Dry weight: 590 kg (1,300 lb)

And the Merlin 61 (why can't Wikipedia set a standard order of UOMs?)

• Length: 88.7 in (225 cm)
• Width: 30.8 in (78 cm)
• Height: 40 in (102 cm)
• Dry weight: 1,640 lb (744 kg)

The Merlin is considerably heavier and longer than the Zero's Merlin. That's a lot of weight placed much further forward of the engine mounts and centre of gravity. I think the handling and the Zero's delicate structure would be badly impacted. And where to place the radiators and coolant lines?

 

[Admiral Beez]

But a dead nuts reliable liquid cooled, smooth as butter V12 surely is worth a look as replacement for a such a noble aircraft as the Mitsubishi Zero. I think it would have been a really beautiful if spartan looking plane. That's my delusion...

There are much better looking and performing Japanese aircraft than the navy's Zero.

I think you have more luck doing it the other way round. The Kawasaki Ki-61 started life as a DB powered inline engine fighter, but morphed into the superlative Kawasaki Ki-100.

 

[AbitNutz]

Per Wikipedia The Nakajima Sakae...

• Length: 1,600 mm (63 in)
• Diameter: 1,150 mm (45 in)
• Dry weight: 590 kg (1,300 lb)

And the Merlin 61 (why can't Wikipedia set a standard order of UOMs?)

• Length: 88.7 in (225 cm)
• Width: 30.8 in (78 cm)
• Height: 40 in (102 cm)
• Dry weight: 1,640 lb (744 kg)

The Merlin is considerably heavier and longer than the Zero's Merlin. That's a lot of weight placed much further forward of the engine mounts and centre of gravity. I think the handling and the Zero's delicate structure would be badly impacted. And where to place the radiators and coolant lines?

I'm telling you...you can't believe Wikipedia or anyone else for these weights. I just don't believe that the 1700 cubic inch Sakae engine weighed only weighed 1300 pounds and the 1650 cubic inch Merlin weighed in at 350 pounds heavier. Something is just not being taken into account. It's true the Merlin is a $hit load longer so you'd likely have to stretch the fuselage a bit behind the cockpit, like they did with the P36 when they turned it in to the P40. But they did it and while the P36 wasn't a bad looking plane, but the P40 was a great looking plane.

I just think that the Mitsubishi Zero would have been an awesome looking and performing plane with a Rolls-Royce Merlin strapped to it. A little liquid cooling added to the Japanese Navy would have done them some good.

 

[wuzak]

The Merlin 61 was a 2 speed, 2 stage with integral aftercooler.

The Sakae was a 2 speed, single stage engine.

The Merlin XX would be more equivalent to the Sakae, but it was still 100-200 pounds heavier.

The reasons include the long crankshaft, camshafts and the long blocks with water passages.

The weight of the engine does not include the cooling system either.

 

[MiTasol]

IF you want reliable weights you need something like Janes AWA where they use the same standard for every engine. I doubt you will find much in Janes on Japanese engines though their editors probably had access to Air Intelligence Unit documents of the time

 

[Admiral Beez]

I just think that the Mitsubishi Zero would have been an awesome looking and performing plane with a Rolls-Royce Merlin strapped to it.

Why do you think this?

A little liquid cooling added to the Japanese Navy would have done them some good.

I disagree. The USN and with the exception of the Fulmar/Firefly and Barracuda even the RN (when not forced to take inline aircraft from the RAF like the Nimrod, Seafire, etc) preferred air cooled radials. For naval service radials are better, less parts to carry, no coolant to manage, etc.

It may look like a simple exercise to swap a radial engine for an in-line, like the P-36 to the P-40, BMW radial powered Focke-Wulf Fw 190A to the in-line Jumo powered F190D or the Reggiane Re.2000 to the Re.2001. But these later aircraft were not simple engine swaps, but were evolutionary design of their own, with significant changes. Considering that Mitsubishi couldn't even get the Zero's evolutionary cousin A7M Reppu into service, there's no hope that they'd get an entirely new design with Merlin into service. And where are they getting the Merlins from? Lol.

Japan doesn't need a 1930's era A6M design with a Merlin grafted on, they need more of their superlative late war radial fighters. The radial-powered Kawanishi N1K, Nakajima Ki-84 and Kawasaki Ki-100 can match anything Merlin-powered.

 

[AbitNutz]

Come on guys, give me a break. The Merlin was a much better engine in every sense of the word "engine" than the under developed pumped up Japanese radials they were trying to cram into the last Japanese airframes at the end of the war. The only engines that they had that were reliable didn't put out any horsepower.
Some say that liquid cooling was a disadvantage because of vulnerability to battle damage. I believe I've read that you were just as likely that you were just as likely to come home in a liquid cooled plane as an air cooled one. As far as making horsepower, liquid cooling is superior. You can get more HP per cubic inch from an LC engine than an AC engine. That's just the nature of it.

As far as aesthetics of a Merlin powered Zero not being beautiful...cut it out! Next thing you'll be telling me is that my dog is ugly!

 

[tomo pauk]

I know, the whole idea on its surface sounds ridiculous, maybe deeper down as well. The A6M8 took the Zero to its max with the Kinsei engine at some 1500 hp. I suspect they were very small and short lived horses at that amount. Anyway, if true, it showed the airframe, at least that airframe, could handle over 1500 hp.
I know the Japanese made a couple of other terrific planes toward the end of the war, the Ki 100, the Ki 84, etc. But a dead nuts reliable liquid cooled, smooth as butter V12 surely is worth a look as replacement for a such a noble aircraft as the Mitsubishi Zero. Far better than being a transporter for a human bomb.

As for engine weight, I don't believe anybody. I've read the 2000 cubic inch DB 601 weighs less than the 1650 cubic inch Merlin. The difference in listed weight between the DB 605 and the Griffon is even worse. I think everybody weighed their engines in different states of dress and I don't think you can believe any of these weights.

I think it would have been a really beautiful if spartan looking plane. That's my delusion...

The Zero with a Merlin in the nose would've been a far better performer (provided you don't mess up the cooing system layout). People were installing V12 liquid-cooled engines on the airframes that have had the radial engine previously in the nose, and a number of those conversions were success - Re.2000 into Re.2001, MC.200 into 202, P-36 into P-40.
As for the weights of differnt Merlins (minus the weight of cooling system), see: link1 link2

 

[DerAdlerIstGelandet]

Come on guys, give me a break. The Merlin was a much better engine in every sense of the word "engine" than the under developed pumped up Japanese radials they were trying to cram into the last Japanese airframes at the end of the war. The only engines that they had that were reliable didn't put out any horsepower.
Some say that liquid cooling was a disadvantage because of vulnerability to battle damage. I believe I've read that you were just as likely that you were just as likely to come home in a liquid cooled plane as an air cooled one. As far as making horsepower, liquid cooling is superior. You can get more HP per cubic inch from an LC engine than an AC engine. That's just the nature of it.

As far as aesthetics of a Merlin powered Zero not being beautiful...cut it out! Next thing you'll be telling me is that my dog is ugly!

Your dog is ugly...

 

[Admiral Beez]

Come on guys, give me a break

Sounds like you just want affirmation and confirmation. Okay, have your Merlin Zero.

 

[swampyankee]

Well, they put an Allison in a P-36, so why not?

 

[MiTasol]

Come on guys, give me a break. The Merlin was a much better engine in every sense of the word "engine" than the under developed pumped up Japanese radials they were trying to cram into the last Japanese airframes at the end of the war. The only engines that they had that were reliable didn't put out any horsepower.
Some say that liquid cooling was a disadvantage because of vulnerability to battle damage. I believe I've read that you were just as likely that you were just as likely to come home in a liquid cooled plane as an air cooled one. As far as making horsepower, liquid cooling is superior. You can get more HP per cubic inch from an LC engine than an AC engine. That's just the nature of it.

As far as aesthetics of a Merlin powered Zero not being beautiful...cut it out! Next thing you'll be telling me is that my dog is ugly!

And where would they put the fuel - the Japanese engines ran on the smell of an oily rag and the Merlin drank fuel like an alcoholic

 

[AbitNutz]

Horsepower takes fuel. There was nothing magic about their engines. When they were ferrying them they ran them lean as $hit. No reason why the same regimen can't be done on a Merlin. I think P-38 pilots learned how to do it. It was either that or learn how to swim. It's true, I don't believe that 1500 hp Merlin is going to burn the same amount of fuel as a 900 hp Sakae. So my pet Zero-Merlin pilots have to learn very careful with engine management and has to use drop tanks for longer missions. We'll get by...and they won't have to put up with the stink of an oily rag.

 

[swampyankee]

Your dog is ugly...

View attachment 558380

That's a dog?

 

[AbitNutz]

Your dog is ugly...

View attachment 558380

 

[AbitNutz]

Hey! He was involved in a freak Cuisinart explosion when one of those damned Sakae engines back fired while running on an oily rag! It was tragic. He used to be a 180 lb Irish Wolf Hound.

 

[Shortround6]

I know, the whole idea on its surface sounds ridiculous, maybe deeper down as well. The A6M8 took the Zero to its max with the Kinsei engine at some 1500 hp. I suspect they were very small and short lived horses at that amount. Anyway, if true, it showed the airframe, at least that airframe, could handle over 1500 hp.
I know the Japanese made a couple of other terrific planes toward the end of the war, the Ki 100, the Ki 84, etc. But a dead nuts reliable liquid cooled, smooth as butter V12 surely is worth a look as replacement for a such a noble aircraft as the Mitsubishi Zero. Far better than being a transporter for a human bomb.

As for engine weight, I don't believe anybody. I've read the 2000 cubic inch DB 601 weighs less than the 1650 cubic inch Merlin. The difference in listed weight between the DB 605 and the Griffon is even worse. I think everybody weighed their engines in different states of dress and I don't think you can believe any of these weights.

I think it would have been a really beautiful if spartan looking plane. That's my delusion...

Believe the weights. The engineers of the time weren't stupid. They designed the engines to stand up to the intended power, that is what helped govern the weight, not the displacement. You can build a light weight large displacement slow turning engine or a similar weight higher rpm smaller displacement engine. See Hispano 12Y engine, displacement of a Griffon, weight less than a Merlin, Power was limited by both the 2400-2500 rpm limit imposed by the crankshaft and the weak construction of the rest of the engine. Russians made the bore 2mm smaller in an attempt to strengthen the cylinder walls.

"Dry" weights are without fluids (oil or coolant), they are also without "accessories" like exhaust manifolds/stacks, starter motors, electric generators and some auxiliary pumps.
Equipped weights can be all over the place. A multi-engine bomber needs bigger generators and hydraulic pumps than a single engine fighter, but then the 4 engine bomber (and even many twins) didn't have generators or hydraulic pumps on all engines.

Fuel is also important, without better than 87 octane fuel the Merlin was going to be limited in power because at much past 6lbs of boost it would run into detonation.
Same for the German engines. The German engines were light weight for their displacement because they knew they would never run the same pressures in the cylinders that the Merlin was going to run and they ran slower.
AN early DB 601 ran at about 80% of the rpm of the early Merlin (the Merlin never changed rpm). It didn't need (or get) the same level of counterweights on the crankshaft. The con rods and Pistons didn't need to be as strong as the Merlins.

The Japanese never got much passed 92 octane fuel (although that is lean rating and Japanese fuel was never rated at rich mixture) so the "dream" of a Zero using a Merlin hits a real snag right at the start.

 

[tomo pauk]

Believe the weights. The engineers of the time weren't stupid. They designed the engines to stand up to the intended power, that is what helped govern the weight, not the displacement. You can build a light weight large displacement slow turning engine or a similar weight higher rpm smaller displacement engine. See Hispano 12Y engine, displacement of a Griffon, weight less than a Merlin, Power was limited by both the 2400-2500 rpm limit imposed by the crankshaft and the weak construction of the rest of the engine. Russians made the bore 2mm smaller in an attempt to strengthen the cylinder walls....

The HS 12Y engines used 2 valve per cylinder heads, that will not be as efficient as the 3, let alone 4 valve per cylinder heads. The early superchargers were both small and inneficient, that will again hurt overall engine performance. The Hs 12Y-49 and -51 were about as good as the DB 601A in altitude power, but came too late to matter, and IIRC required 100 oct fuel to operate due to the CR raised to 7.0:1.

Fuel is also important, without better than 87 octane fuel the Merlin was going to be limited in power because at much past 6lbs of boost it would run into detonation.
Same for the German engines. The German engines were light weight for their displacement because they knew they would never run the same pressures in the cylinders that the Merlin was going to run and they ran slower.
AN early DB 601 ran at about 80% of the rpm of the early Merlin (the Merlin never changed rpm). It didn't need (or get) the same level of counterweights on the crankshaft. The con rods and Pistons didn't need to be as strong as the Merlins.

The Japanese never got much passed 92 octane fuel (although that is lean rating and Japanese fuel was never rated at rich mixture) so the "dream" of a Zero using a Merlin hits a real snag right at the start.

On 91 oct US fuel (= as used in the training units at the CONUS), the V-1650-1 was rated for 44.2 in Hg boost (max) and 40 in Hg (recomended). That means +7 in Hg (max) and +4.9 (recomended), respectively, thus max power being ~1000 HP at 21000 ft (high gear) or ~1200 HP at 13000 ft (low gear) - basically, power figure at 20000-21000 ft being the same as for the Ha-40 or DB 601A at ~13500 ft.
Japanese have historically dealt with lack of hi-oct fuel by using water/alcohol injection, though this was pretty much late-war tech, and not universaly spread.

 

[Macandy]

I'm telling you...you can't believe Wikipedia or anyone else for these weights. I just don't believe that the 1700 cubic inch Sakae engine weighed only weighed 1300 pounds and the 1650 cubic inch Merlin weighed in at 350 pounds heavier. Something is just not being taken into account. It's true the Merlin is a $hit load longer so you'd likely have to stretch the fuselage a bit behind the cockpit, like they did with the P36 when they turned it in to the P40. But they did it and while the P36 wasn't a bad looking plane, but the P40 was a great looking plane.

I just think that the Mitsubishi Zero would have been an awesome looking and performing plane with a Rolls-Royce Merlin strapped to it. A little liquid cooling added to the Japanese Navy would have done them some good.

big long massively heavy crankshaft one an in-line... it's why they died out in favour if radials.