WWII Aero Engines

I'd like to trawl for any forum members interested in getting chat going re WWII aero engines, i.e., what they consider to be the outstanding powerplants that either got into action or failed to make it.

I think that the Pratt & Whitney R2800 series of engine was he workhorse of the Usa Aircraft for the Navy and Army Air Corp !! The radial design had the best power to weight ratio and ease of maintenance of any of the Aero engines !! It could taken a beating and still got the pilots home !!! Consider the the Engine started in the 1800 hp range and ended above the 2500 hp through the war years .

Hmmm, I'd have to say the Junker Jumo 004 turbo jet screams "outstanding' in the WWII context. Even jet's most primitive form had any piston engine beat.

The RR Merlin 61 could be a candidate. It's two stage/two speed supercharger, 4 valve per cyl, overhead cam(s) sure was slick. I don't think any planes they stuffed it into were nick named after a crapper...

The R-4360 has the R-2800 beat (power to weight, peak output, fuel comsumption...). It just made the War, but missed the show ( It did not see action). Its ironic how fast the summit of piston engines was forgotten after the war. Probably the cost of rebuild after 1000hrs (or less) had something to do with that.

M813A1 said:

I think that the Pratt & Whitney R2800 series of engine was he workhorse of the Usa Aircraft for the Navy and Army Air Corp !! The radial design had the best power to weight ratio and ease of maintenance of any of the Aero engines !! It could taken a beating and still got the pilots home !!! Consider the the Engine started in the 1800 hp range and ended above the 2500 hp through the war years .

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Hi M81,
Couldn't agree more, but do you have any favourites among the also rans?
Regards,
Lezza.

jimk said:

Hmmm, I'd have to say the Junker Jumo 004 turbo jet screams "outstanding' in the WWII context. Even jet's most primitive form had any piston engine beat.

The RR Merlin 61 could be a candidate. It's two stage/two speed supercharger, 4 valve per cyl, overhead cam(s) sure was slick. I don't think any planes they stuffed it into were nick named after a crapper...

The R-4360 has the R-2800 beat (power to weight, peak output, fuel comsumption...). It just made the War, but missed the show ( It did not see action). Its ironic how fast the summit of piston engines was forgotten after the war. Probably the cost of rebuild after 1000hrs (or less) had something to do with that.

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Hi Jimk
Agree.
The USAF couldn't wait to ditch the Curtiss-Wright R-3350 in favour of the
R-4360 for the B-50, although it still got aboard other notable airframes, e.g., Lockheed Neptune.
Got an opinion on the R-3350?
If it had difficulties, what about the Napier Sabre?
I also notice in another thread that you're across the Continental X-7750.
With jet turbines on the way, why did the Government keep throwing money at a programme that had no future after the R-4360 was selected for the B-36?
Wonder how the X-7750 would have gone in the B-36.
Lezza.

I'm in the process of rebuilding an Allison V1710 right now. It has to run by next month... Making 66-year old worn out parts into a running machine takes patience. And a little luck, though this isn't the first Allison I've helped assemble. But this one is far more a collection of worn out junk, we are even using major parts off a trashed, former static display engine to make this one run. Money is tight and parts are scarce.

But it's not going into an airplane.

1957 U-77 MISS Wahoo Vintage Unlimited Hydroplane
Hydroplane & Raceboat Museum - Kent, WA.
(Donations of parts always accepted... even engines that have had a rod saw the case in half can provide valuable pieces)

The Allison might not have been the most powerful, but it was overbuilt. Wartime engines just scratched 1500HP; they were pushing 3000HP as race engines in the late 50s and some still do. And the plane it powered was no slouch- the venerable P-38 Lightning.

Hello Datsun !! I aree the Allison V-1710 was a good engine and well overbuilt !! That engine was a out growth of the WW 1 Liberty Engines !! The only fault I can see with the
V -1710's were that the supercharger was a little to small for it ?? Had it had a larger or a better 2 stage supercharger it might have donee better at altitude !! The Rolls Royce Merlin was a Good engine too. Its larger supercharger made it a much better engine at altitude !! All be it, the use of 2, V-1710's in the Lockheed P-38 Lighting workout very good in that plane !! There is nothing better then to see and hear those old running wether in a plane, boat or tractor puller they always sound great !!

Yes, the single-stage centrifugal supercharger was the Allison's biggest drawback, but it was the USAAF that demanded it be that configuration- they believed that turbo-supercharging using exhaust would provide better results, and they intended it to always be a low-altitude engine.

Of course, when the Brits got the first P-51s they stuck Merlins in them... the performance difference was astounding, and RR licensed Packard to make Merlins here, and the P-51D was born.

But the -7 and -9 Packard Merlin's 2-stage, 2-speed blowers and the resultant complexity were also their weakest point. They ran higher HP and altitude, but at a cost of reliability. Not a huge issue when the life expectancy of an engine was under 100 hours. But the Merlin adapted to boat racing after the war just like the Allison- just that the Merlin took a lot more money and skill to keep running, and they tended to come apart much easier. So basically the big-money guys ran the more powerful Merlin, and the little guys ran the Allison, until the boats started using turbines (T-55 Lycomings) in the 1980s. Also military surplus.

GM-Allison did attempt to design a 2-stage V1710, and the Aux stage V1710-G6 -143/145 was the end result. Unfortunately it was horribly unreliable due to the added complexity. The end of the war, coinciding with the beginning of the Jet age, ended all factory development of the big aero piston engines.

love the rolls royce merlin. as the mustang is my favorite plane . I love the sound of the merlin.

Mustangs are sweet but I'm a big fan of the "Jug" (P-47)

datsunaholic said:

I'm in the process of rebuilding an Allison V1710 right now. It has to run by next month... Making 66-year old worn out parts into a running machine takes patience. And a little luck, though this isn't the first Allison I've helped assemble. But this one is far more a collection of worn out junk, we are even using major parts off a trashed, former static display engine to make this one run. Money is tight and parts are scarce.

But it's not going into an airplane.

1957 U-77 MISS Wahoo Vintage Unlimited Hydroplane
Hydroplane & Raceboat Museum - Kent, WA.
(Donations of parts always accepted... even engines that have had a rod saw the case in half can provide valuable pieces)

The Allison might not have been the most powerful, but it was overbuilt. Wartime engines just scratched 1500HP; they were pushing 3000HP as race engines in the late 50s and some still do. And the plane it powered was no slouch- the venerable P-38 Lightning.

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Hi Datsunaholic,
What exactly do you mean by overbuilt?
Regards,
Lezza.

Who made the quote for the Jumo 004???? You kidding????? The concept was there but the metals were not...........reliability was crap, they were taken apart after about 10 flight hrs if they did not come apart on their own.

YES on the R2800..............cant beat it for a radial.

For a V, sorry guys............. DB601!!!
[media]http://www.youtube.com/watch?v=mzgYkfq9OVw&feature=related[/media]


Dont get me wrong, I am a aircraft mechanic and I have been around radial engines all my life!!!

Wright 760-8 on our N3N.
[media]http://www.youtube.com/watch?v=umDY2eqsPGc&feature=channel_page[/media]

Hi Vtdeucedriver,
You're right about the materials aspect of the Jumo 004, but if you take the state of German industry at the time, it was a tremendous technical achievement. The US 8th AF can be grateful that political & organisational machinations delayed the Me-262. The other thing to remember is that the 004 was an axial design and well ahead of the British Whittle.
Tell me why you think the DB-601 was a better engine than the Merlin?
Regards,
Lezza.

Lezza said:

Hi Vtdeucedriver,
You're right about the materials aspect of the Jumo 004, but if you take the state of German industry at the time, it was a tremendous technical achievement. The US 8th AF can be grateful that political & organisational machinations delayed the Me-262. The other thing to remember is that the 004 was an axial design and well ahead of the British Whittle.
Tell me why you think the DB-601 was a better engine than the Merlin?
Regards,
Lezza.

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Fuel Injection.

M813A1 said:

Hello Datsun !! I aree the Allison V-1710 was a good engine and well overbuilt !! That engine was a out growth of the WW 1 Liberty Engines !! The only fault I can see with the
V -1710's were that the supercharger was a little to small for it ?? Had it had a larger or a better 2 stage supercharger it might have donee better at altitude !! The Rolls Royce Merlin was a Good engine too. Its larger supercharger made it a much better engine at altitude !! All be it, the use of 2, V-1710's in the Lockheed P-38 Lighting workout very good in that plane !! There is nothing better then to see and hear those old running wether in a plane, boat or tractor puller they always sound great !!

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I'm curious: I thought the P-38 had good high altitude performance, despite being fitted with the Allison engine. I always wondered about that until the CAF brought some B-17's to Lunken Airport in Cincinnati. I hadn't realized until then that B-17's had turbochargers in the lower rear area of the nacelles (almost burned my hand on one). The turbochargers appeared to be identical to the ones on the P-38, seen on the top of the rear boom area, between the radiator scoops. As I understood it, those turbos were made by GE.

I recall it was a D'oh moment for me, realizing that B-17's were combat operated up where turbo/supercharging would be a requirement.

So I presume the A-36 with the Allison engine had a small supercharger, but the P-38 was fitted with a GE turbocharger large enough to breathe a B-17 radial?

maybefixit said:

I'm curious: I thought the P-38 had good high altitude performance, despite being fitted with the Allison engine. I always wondered about that until the CAF brought some B-17's to Lunken Airport in Cincinnati. I hadn't realized until then that B-17's had turbochargers in the lower rear area of the nacelles (almost burned my hand on one). The turbochargers appeared to be identical to the ones on the P-38, seen on the top of the rear boom area, between the radiator scoops. As I understood it, those turbos were made by GE.

I recall it was a D'oh moment for me, realizing that B-17's were combat operated up where turbo/supercharging would be a requirement.

So I presume the A-36 with the Allison engine had a small supercharger, but the P-38 was fitted with a GE turbocharger large enough to breathe a B-17 radial?

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Hi Maybefixit,
Couple of points.
I've always wondered why Allison didn't try and license R-R supercharger technology.
May have had something to do with the fact that Packard and R-R were well down the track with plans to build the Merlin in the US & conflict of interest may have come into it.
Posters may not be aware that all this was well underway before someone in the UK had the bright idea of slipping a Merlin into a Mustang.
Interesting thing about the P-38 is that it was offered to the RAF without turbochargers because some bureaucraft in either Lockeed or the Government thought they were so top secret that the limeys couldn't be trusted with them.
The RAF refused the P-38.
Can you imagine what a deathtrap it would've been without TC?
This was a real slap in the face for the British in view of their attitude toward technology transfers.
Is anyone going to try and tell me that R-R and the British Government did the deal with Packard without realising that every single detail of the Merlin would leak to Allison and other liquid-cooled engine builders in the US?
Regards,
Lezza.

WWII aero engines

My vote goes for the rolls royce Griffon..heres some pics from the home of the worlds fastest motorsport-air racing..not the slow red bull racing..but real WWII unlimted airacing at Reno,Nevada...here's some pics of #38 precious metal a highly modified P-51 with a rolls royce griffon..notice the counter rotating props..also a video of the plane doing a fly by on the fastest section of the 8 mile course..speeds here are over 450 mph..turn it up and enjoy
[media]http://www.youtube.com/watch?v=HVWmI1PMUUs[/media]

Lezza said:

Hi Datsunaholic,
What exactly do you mean by overbuilt?
Regards,
Lezza.

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What I mean by "overbuilt" is that the Allison's main components could handle far more horsepower than the engine was designed to produce. The Merlin, OTOH, wasn't quite as stout. Its components were far closer to design tolerance. It made the Merlin lighter per HP but more fragile. Reno Air racers have used Allison rods in the Merlins for this vary reason- the Merlin rods are 3-piece assemblies, whereas the Allison rod is 2-piece. The "big end" on the Allison is quite a bit larger as well, since the rod journals are much larger.


I will have to agree with the sheer "badass" of the Rolls Griffon, though. Those engines are something else. Fire one of those bad boys up and EVERYONE notices.

mutt_kahuna said:

My vote goes for the rolls royce Griffon..heres some pics from the home of the worlds fastest motorsport-air racing..not the slow red bull racing..but real WWII unlimted airacing at Reno,Nevada...here's some pics of #38 precious metal a highly modified P-51 with a rolls royce griffon..notice the counter rotating props..also a video of the plane doing a fly by on the fastest section of the 8 mile course..speeds here are over 450 mph..turn it up and enjoy
[media]http://www.youtube.com/watch?v=HVWmI1PMUUs[/media]

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Hi Mutt-kahuna,
Lovely stuff.
The video audio may not be a completely true reflection of the Griffon's sound, but I gained the impression that it sounded sharper and harsher than a Merlin.
Mind you, the Merlins we hear out in Oz are treated very gently.
I've heard Griffins in anger just once, and under very unusal circumstances.
Many years ago - a lifetime actually - I found myself aboard a Royal Navy destroyer in the Irish Sea when, quite unexpectedly, we were subjected to a beatup by an Avro Shackleton which ended in a spectacularly steep pull-up.
I can still hear the four Griffons - a deep, thunderous roar.
I agree that this was a fabulous engine and it would 've played a far greater role in WII had R-R not been so committed to the Merlin.
36 litres displacement against 27 with - hope I've remembered this correctly - only a 17% increase in frontal area and heaps more grunt.
Have you heard the story about the day they put on a match race between the Spitfire-Griffon prototype, a Hawker-Typhoon and a captured FW-190?
In the dying days of the IC engine, R-R had another trick up its sleeve which would have shaded the Merlin / Griffon.
Familiar with the Crecy?
Regards,
Lezza.

We are starting to see the Griffons used in tractor pullers out here in addition to the Allisons. The people that I have talked to also said that the Griffons had weak rods but apparently the Allison has a weak main? IIRC it was #4? Any truth to the rumor that somebody is building NEW Allisons?