And you would have had an aeroplane with worse performance than it actually had in real life... So, tell me what the benefits of your idea are?
Engine choices for P-51 mustang ?
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And you would have had an aeroplane with worse performance than it actually had in real life... So, tell me what the benefits of your idea are?
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- #22
More hp from less displacement for one and 2 sinve the A-36 was used as a bomber the bigger hp would mean more load carried at one time compared to the V-1710 snaillson .
Admiral Beez
Major
Some discussion here…. P51 with Griffon engine?
Admiral Beez
Major
I'd like to see the P-47 sized liquid cooled giant the US would have designed around the Sabre. They'd likely make it more reliable as well, though aero engine sleeve valves might be out of their wheelhouse - but perhaps not due to the US earlier history with automotive sleeve valves.
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Shortround6
Major General
The Sabre had a lot of promise, in practice it was piece of crap.
A very expensive piece of crap.
A very, very expensive piece of crap.
Now in regards to this.
First (or 3rd?) we need Dr. Who and the Tardis.
Somewhere in there we need to repeal the laws of physics.
Gloster managed to build 250 Typhoons between Sept 1941 and June of 1942.
Hawker built 15 Typhoons with deliveries starting in Nov 1941, mostly as prototype/trials aircraft.
By end of June of 1942 NA had built over 600 Mustangs. The design of the Mustang was well established and NA was cranking out just over 80 planes month.
Allison was cranking out 1100-1200 engines a month in the 1st 6 months of 1942.
How many engines per month was Napier or English electric making?
At what point did Napier even get the Sabre to even a semi useful engine in 1942
It can take well over 1 year to build a new factory to make engines so when do you start?
An Allison went a bit over 1300lbs and the radiator and propeller (and other bits) were sized to suit.
A Sabre was well over 2300lbs (later ones were close to 2500lbs) and needed radiators and propeller (and other bits) to suit.
The engine and prop were in the nose. It doesn't matter what you take out of the plane to lighten it up (in fact it is better if you don't take anything out) as the plane will be exceeding nose heavy and may not even fly. I mentioned physics, things like center of gravity which has to be over/near the center of lift. Having a strong enough airframe, adding 1500lbs of engine and propeller (and bits ) or more and trying to get the fighter plane to turn at high "G" forces without breaking the plane means you need a heavier airframe.
There are reasons that the Typhoon and Tempest and the P-47 and F4U/F6F all went around 11,000lb or more. You need a plane that big and heavy to support a 2000hp engine.
If you want to use the Sabre you need to start with the Sabre in 1940 and design the plane around it. You can't drop the Sabre into a plane designed for a much smaller engine.
By the Summer and fall of 1942 people were thinking about dropping the two stage Merlin into the Mustang.
For the US there were no other options. It was either Allisons in P-51As & A-36s or single stage Merlins (with a disruption in production) AND no Merlin P-40Fs-lLs , which might not be a net gain even if you build more P-40Ks.
As far the whole Hispano thing goes, not matter what the source. Think about it.
In NA and in 1943 in Sicily Italy you are going to replace Allisons that if not dealing with desert sand, would run for 300 or more hours with Hispano's (or Russian versions) that had trouble running for 1/3 of that time. Now try and run them in desert sand.
And the Sabre hated dusty/dirty conditions.
A very expensive piece of crap.
A very, very expensive piece of crap.
Now in regards to this.
There is so much wrong here that I a left shaking my head in wonder.
First (or 3rd?) we need Dr. Who and the Tardis.
Somewhere in there we need to repeal the laws of physics.
Gloster managed to build 250 Typhoons between Sept 1941 and June of 1942.
Hawker built 15 Typhoons with deliveries starting in Nov 1941, mostly as prototype/trials aircraft.
By end of June of 1942 NA had built over 600 Mustangs. The design of the Mustang was well established and NA was cranking out just over 80 planes month.
Allison was cranking out 1100-1200 engines a month in the 1st 6 months of 1942.
How many engines per month was Napier or English electric making?
At what point did Napier even get the Sabre to even a semi useful engine in 1942
It can take well over 1 year to build a new factory to make engines so when do you start?
An Allison went a bit over 1300lbs and the radiator and propeller (and other bits) were sized to suit.
A Sabre was well over 2300lbs (later ones were close to 2500lbs) and needed radiators and propeller (and other bits) to suit.
The engine and prop were in the nose. It doesn't matter what you take out of the plane to lighten it up (in fact it is better if you don't take anything out) as the plane will be exceeding nose heavy and may not even fly. I mentioned physics, things like center of gravity which has to be over/near the center of lift. Having a strong enough airframe, adding 1500lbs of engine and propeller (and bits ) or more and trying to get the fighter plane to turn at high "G" forces without breaking the plane means you need a heavier airframe.
There are reasons that the Typhoon and Tempest and the P-47 and F4U/F6F all went around 11,000lb or more. You need a plane that big and heavy to support a 2000hp engine.
If you want to use the Sabre you need to start with the Sabre in 1940 and design the plane around it. You can't drop the Sabre into a plane designed for a much smaller engine.
By the Summer and fall of 1942 people were thinking about dropping the two stage Merlin into the Mustang.
For the US there were no other options. It was either Allisons in P-51As & A-36s or single stage Merlins (with a disruption in production) AND no Merlin P-40Fs-lLs , which might not be a net gain even if you build more P-40Ks.
As far the whole Hispano thing goes, not matter what the source. Think about it.
In NA and in 1943 in Sicily Italy you are going to replace Allisons that if not dealing with desert sand, would run for 300 or more hours with Hispano's (or Russian versions) that had trouble running for 1/3 of that time. Now try and run them in desert sand.
And the Sabre hated dusty/dirty conditions.
Shortround6
Major General
P & W was working on several sleeve valve engines in 1939-40. They shit canned all them to concentrate on the R-2800 and they didn't think they could get them to production status before the war would be over.
From Wiki and it is brief
Pratt & Whitney X-1800 - Wikipedia
Pratt & Whitney XH-3130 - Wikipedia
Getting P & W to build the Sabre instead of one of their own was probably not going to happen.
Wright went down the Tornado 42 cylinder rathole and just barely emerged in time to get the R-3350 going (and we know how that turned out)
Geoffrey Sinclair
Staff Sergeant
- 922
- Sep 30, 2021
Gloster built 93 Typhoon Ia between June 1941 and June 1942, plus another 7 in July and August.
Gloster built 130 Typhoon Ib between February and June 1942.
Hawker built 5 Typhoon Ia, officially 2 in March, 1 in April and 1 in June 1942 and 1 in March 1943, its 10 mark Ib were built 2 in September and 3 in December 1942, then 3 in March and 2 in April 1943.
By end 1942 some 966 production Sabres of all versions had been built, versus 714 Typhoons. By end 1943 it was 2,117 Sabres of all versions for 1,851 Typhoons and 3 Tempests. That is a tight supply situation before taking into account the reliability of the Sabre.
Cumulative production totals Sabre II and Typhoon, then Sabre II engines under repair and Typhoon airframes in storage as of end of month,
Writing off, scrapping, reducing to spares several hundred Typhoon airframes would be needed to ensure all existing airframes had an engine plus allow for engine repairs, overhaul and reserves, and the newly arriving Tempests. I do not think there was enough wrong with the early Typhoon airframes to require scrapping, it was engine supply.
Inventory of Typhoons in 1943. Either the RAF was losing an average of 100 Typhoons a month June to September inclusive or there was quite a culling, all up 387 written off in the 4 months.
Feb 43 Effective 734, lost 98 including Cat E 79
Mar 43 Effective 834, lost 117 including Cat E 101
Apr 43 Effective 922, lost 149 including Cat E 133
May 43 Effective 935, lost 212 including Cat E 152
Jun 43 Effective 897, lost 338 including Cat E 277
Jul 43 Effective 944, lost 413 including Cat E 354
Aug 43 Effective 919, lost 514 including Cat E 452
Sep 43 Effective 913, lost 603 including Cat E 539
Oct 43 Effective 971, lost 657 including Cat E 589
Nov 43 Effective 984, lost 748 including Cat E 632
Dec 43 Effective 1,060, lost 775 including Cat E 661
Put it another way, as of the end of 1943, there were 1,159 (2,030 - 871) Sabre II engines available for or had been lost with Typhoons, there were 265 Typhoon airframes in storage, so assuming a maximum of 1,424 (1,159+265) Typhoons with engines or as airframes requires the scrapping or reassigning to maintenance airframe status of around 427 airframes to balance the books and this ignores there would be stand alone Sabre II engine reserves. As of end December 1943 there were 114 Typhoon Instructional aircraft (from 1,851 Typhoons built), versus 120 Spitfires and 174 Hurricanes.
Gloster built 130 Typhoon Ib between February and June 1942.
Hawker built 5 Typhoon Ia, officially 2 in March, 1 in April and 1 in June 1942 and 1 in March 1943, its 10 mark Ib were built 2 in September and 3 in December 1942, then 3 in March and 2 in April 1943.
By end 1942 some 966 production Sabres of all versions had been built, versus 714 Typhoons. By end 1943 it was 2,117 Sabres of all versions for 1,851 Typhoons and 3 Tempests. That is a tight supply situation before taking into account the reliability of the Sabre.
Cumulative production totals Sabre II and Typhoon, then Sabre II engines under repair and Typhoon airframes in storage as of end of month,
| Month | Sabre II | Typhoon | Sabre under or awaiting repair | Typhoon airframes in storage |
Jan-43 | 1007 | 805 | 317 | 166 |
Feb-43 | 1115 | 890 | 352 | 158 |
Mar-43 | 1222 | 994 | 417 | 158 |
Apr-43 | Unknown | 1097 | 482 | Unknown |
May-43 | 1334 | 1200 | 595 | 244 |
Jun-43 | 1391 | 1264 | 643 | 183 |
Jul-43 | 1482 | 1357 | 735 | 153 |
Aug-43 | 1586 | 1437 | 861 | 149 |
Sep-43 | 1695 | 1547 | 887 | 304 |
Oct-43 | 1805 | 1645 | 901 | 176 |
Nov-43 | 1913 | 1753 | 897 | 206 |
Dec-43 | 2030 | 1851 | 871 | 265 |
Writing off, scrapping, reducing to spares several hundred Typhoon airframes would be needed to ensure all existing airframes had an engine plus allow for engine repairs, overhaul and reserves, and the newly arriving Tempests. I do not think there was enough wrong with the early Typhoon airframes to require scrapping, it was engine supply.
Inventory of Typhoons in 1943. Either the RAF was losing an average of 100 Typhoons a month June to September inclusive or there was quite a culling, all up 387 written off in the 4 months.
Feb 43 Effective 734, lost 98 including Cat E 79
Mar 43 Effective 834, lost 117 including Cat E 101
Apr 43 Effective 922, lost 149 including Cat E 133
May 43 Effective 935, lost 212 including Cat E 152
Jun 43 Effective 897, lost 338 including Cat E 277
Jul 43 Effective 944, lost 413 including Cat E 354
Aug 43 Effective 919, lost 514 including Cat E 452
Sep 43 Effective 913, lost 603 including Cat E 539
Oct 43 Effective 971, lost 657 including Cat E 589
Nov 43 Effective 984, lost 748 including Cat E 632
Dec 43 Effective 1,060, lost 775 including Cat E 661
Put it another way, as of the end of 1943, there were 1,159 (2,030 - 871) Sabre II engines available for or had been lost with Typhoons, there were 265 Typhoon airframes in storage, so assuming a maximum of 1,424 (1,159+265) Typhoons with engines or as airframes requires the scrapping or reassigning to maintenance airframe status of around 427 airframes to balance the books and this ignores there would be stand alone Sabre II engine reserves. As of end December 1943 there were 114 Typhoon Instructional aircraft (from 1,851 Typhoons built), versus 120 Spitfires and 174 Hurricanes.
Deleted member 68059
Staff Sergeant
- 1,058
- Dec 28, 2015
Sabre no good for this role for myriad reasons, but forgetting cost/size/weight/reliability, the supercharger wasnt up to it until the war was basically over.
At the time, there was no other engine than a 2-stage Merlin which was vague plausible in terms of someting you could actually make and
have in reliable quantity. Its incredibly difficult to beat a Merlin-66, if your goal is performance between about 25 and 35,000feet which is why lots got made.
The Sabre (until the end of the war) is inferior to a Merlin-66 above 20,000ft, and due to the massive weight penalty (+1000lbs dry)
the "installed power" if you want to call it that, will be less impressive still (taking into account significant drag increase due to
increased weight, frontal area, etc etc).
At the time, there was no other engine than a 2-stage Merlin which was vague plausible in terms of someting you could actually make and
have in reliable quantity. Its incredibly difficult to beat a Merlin-66, if your goal is performance between about 25 and 35,000feet which is why lots got made.
The Sabre (until the end of the war) is inferior to a Merlin-66 above 20,000ft, and due to the massive weight penalty (+1000lbs dry)
the "installed power" if you want to call it that, will be less impressive still (taking into account significant drag increase due to
increased weight, frontal area, etc etc).
Shortround6
Major General
the only thing that was vaguely plausible was the Allison with a turbo like was used in the P-38L.
Now can can you build more of them (swipe turbos from B-17s/B-24s) ?
Can you stuff the P-38 system into a single engine fighter?
You could but it is going to need more internal volume than the Merlin 66.
It certainly maybe more expensive, the turbo is going to cost more than the extra stage on the Merlin which does not need high temperature alloys.
The P-38L could make 1495hp at 26,000ft WEP at 60 inches.
Granted this was several years after 1942 however the main limitation of a P-38G engine not making 1300hp at 25,000ft was the inadequate intercooler set up. It was not the engine could not make or stand up to the power and it wasn't that the turbo could not supply the desired amount of air. The limit was that the incoming air was too hot due to the inadequate intercooler.
When all is said and done the Turbo Allison was not as good a choice as the Merlin but it was a whole lot more plausible than using the Sabre engine at high altitude.
Deleted member 68059
Staff Sergeant
- 1,058
- Dec 28, 2015
"Can you stuff the P-38 system into a single engine fighter?"
Not unless you designed the whole aircraft around it from day-1, which is essentially then a P-47.
You would not want to do this with something the size of a Merlin of V-1710, because the very significant extra
weight will nullify the point of the exersize. Having a R-2800 with nearly double the swept volume
gives you a big head start power reserves wise.
It takes very little weight increase to totally kill high altitude gains, even doing something like fitting a pressure-cabin
to a Me109G resulted in so much weight increase that it was judged to be a waste of time, as the whole point of the pressure cabin
was to allow extended flight at very high altitude.
Shortround6
Major General
P-51 with Merin used an 11ft 2in prop, with an Allison it used a 10ft 9in prop.
Using a 14ft prop would put your prop tips almost 1 ft underground if the tail comes up.
You are going to need at least a 6 blade contra rotating propeller to handle the power at a usable diameter.
Everybody wanted 2000hp at 30,000ft. The problem was getting it out of a 2550lb package (engine, prop, radiator/coolant, accessories, including engine mounts/cowling).
Stuffing a 4000lb powerplant into the Mustang simply wasn't going to happen, especially a powerplant from 1944. well into 1944.
The Mustang was designed/ developed in 1940. That is an already existing fuselage design had Laminar wings added. The first Mustangs started arriving in UK in late 1941, after testing in April 1942 work stated on both sides of the Atlantic to fit the two stage Merlin. These started to be made in early 1943 arriving in UK in mid 1943. By the start of "Big Week" Operation Argument in Feb 1944 there were approx 100 P-51Bs in service. The A36 was a financial or logistical/ budget "dodge" to keep production lines running until P-51Bs started to be made. If you start figuring out how to fit a Sabre into a Mustang in late 1942 any product of the project would arrive in UK after the end of the war. Only the Typhoon and Tempest used Sabre engines and the Tempest Sea Fury later switched to the Centaurus because the Sabre was a dog of an engine. The Sabre was bigger, heavier, used more fuel and had less altitude performance than the Merlin. While bothe the Merlin and Allison used less fuel on cruise and gave high performance on max power, just at different altitudes. The British would have taken more Allisson engined Mustangs right to the end of the war, they performed better than all others a very important niche. Whatever your opinion of the Allisson engine, whether it was indeed the worst produced in USA, try writing WW2 without the P-38 and P-40.
Shortround6
Major General
To your point.
The Curtiss P-60 with a planed turbo Allison. Maybe they didn't need all of the larger wing (planed eight .50 cal guns) but they sure bulked up the fuselage.
Curtiss actually had an order for 1950 of these aircraft, for a few months. And well before it flew. As tested in 1943 it weighed 7800lbs empty and normal gross of 9,616lbs (well under a P-47 but well over a P-51) and max gross of 10,160lbs. The planned for eight .50s had dropped to six .50s with 1200rounds of ammo total at this point.
An earlier P-60 version with the same Merlin engine used the P-40F does illustrate your point quite well.
Note the somewhat more visible components of the P-40 fuselage around the cockpit.
Please note that the P-53/P-60 series started out with Continental V-1410 engine and it's problems so everything after that was a salvage operation.
A P-51 with a turbo Allison may have been doable but it was going to fatter than the Merlin Mustang, as you have said. But it was the only alterative with any chance at at all.
Mike Williams
Senior Airman
- 572
- Oct 19, 2006
Interesting, I don't recall reading anything about pressure cabin Me 109 Gs being judged a waste of time due to weight issues. Do have a source for that? Thanks.
Yet even the Allison engined Mustang I could match the performance of the Typhoon at a higher altitude and the Merlin engined Mustang could comfortably exceed it, but you'd rather condemn the Mustang to worse performance than it actually had by sticking a bigger, heavier and worse performing engine at altitude?
You also forget that the Sabre was very troublesome at the time it was being fitted into the Typhoon. since you've quoted from Wikipedia, here's a bit about the Sabre...
"Problems arose as soon as mass production began. Prototype engines had been hand-assembled by Napier craftsmen and it proved to be difficult to adapt it to assembly-line production techniques. The sleeves often failed due to the way they were manufactured from chrome-molybdenum steel, leading to seized cylinders, which caused the loss of the sole prototype Martin-Baker MB 3.[9][10] "
Other issues affected Sabre production and maintenance...
"Quality control proved to be inadequate, engines were often delivered with improperly cleaned castings, broken piston rings and machine cuttings left inside the engine.[12] Mechanics were overworked trying to keep the Sabres running and during cold weather they had to run them every two hours during the night so that the engine oil would not congeal and prevent the engine from starting the next day.[nb 3] These problems took too long to remedy and the engine gained a bad reputation. To make matters worse, mechanics and pilots unfamiliar with the different nature of the engine, tended to blame the Sabre for problems that were caused by not following correct procedures. This was exacerbated by the representatives of the competing Rolls-Royce company, which had its own agenda."
Here's a bit about the Sabre from the Wiki page on the Typhoon...
"The Sabre engine was also a constant source of problems, notably in colder weather, when it was very difficult to start, and it suffered problems with wear of its sleeve valves, with consequently high oil consumption. The 24-cylinder engine also produced a very high-pitched engine note, which pilots found very fatiguing."
So, you really think putting a Sabre in the Mustang will make it better?
Deleted member 68059
Staff Sergeant
- 1,058
- Dec 28, 2015
There is of course nothing unique about this experience, and generally, apart from a few stripped out PR aircraft almost nobody flew anything in operationally significant numbers with working pressure-cabins except a very few right near the end of the war, for most of the same reasons stated here.
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Mike Williams
Senior Airman
- 572
- Oct 19, 2006
Thank you.
drgondog
Major
The Allison V-1710 was only sub-optimal at high altitudes when compared to Merlin 60 series. That said it (V-1710-109 w/WI) was producing as much or more Hp than the Packard V-1650-3 and about same as -7 at WEP. The turbos maintained the Hp at high altitude better for P-38 than any P-51, including the H.
The Only issue for the Allison was the lack of an integral second stage similar to Merlin 60 series. The auxilary 2nd stage worked only for a/c built around it to accomodate length and weight. Retro fitting was a 'no go' for the Mustang. Ditto for P-39 and P-40 and -38.
As to your other comments about engine switch for Mustang;
NAA developed a sincere hatred for Allison as early as as the NA-73X, for which Allison failed to deliver per contract schedule because they (Allison) management dismissed NAA schedule for late August 1940 delivery and contined to fail until AAC 'loaned' a V-1710-39 to install in October.
Allison treated NAA as bastard stepchild believing that GM Board would keep NAA from going in a different direction - and they were correct until NA-101 contract for XP-78 (later XP-51B) was let in mid 1942.
NAA (Kindelberger) began relationship with R-R in US in 1941, and began preliminary studies for Merlin XX (Packard 1650-1) but was shut down by GM Board i early 1942. At or about the same time, NAA was looking at Continental, then R-R again for Griffon in 1942. The Griffon was rejected but NAA was forced by the Board to justify selecting Merlin 61 over Allison w/auxilary 2nd stage in late 1942 and were able to justify based on major design changes on airframes to accomodate versus relatively few changes with Merlin. There were major political forces at work, including with Materiel Command/AAF-HQ requirements division; R-R and RAF seeking license agreement w/NAA to ship airframe kits to UK for assembly and install of engines in UK - which would absorb major production resources of NAA to supply RAF; Forces within MC as more officers favored P-51 for purchase;
There was never going to be a front mounted Griffon or Sabre in a P-51 because of long lead times to re-design and place into production.
Interestingly, the P-51B was intially placed into TAC ONLY because that was the decision for A-36 and P-51A. When Fairchild ran over Echols and pushed P-51A AND option to transition remaining P-51A to P-51B, nobody at HQ or Air Defense Command (where priority assignments were made) were thinking of anythng but P-38 and P-47 for high altitude escort.
The P-51A, had it continued co-production, would have been a superb TAC fighter, particularly after WI ws introduced to 1710-81, giving it 1600+ HP and very good climb and acceleration, as well as recon and CAS role. Even though HP tapered after 15K, it was still superior in overall performance to F6F below 20K and still much faster above 20K. The F6F would always turn better,but the P-51A could choose to engage - or leave.
What the P-51A could not do was long range escort at high altitude in ETO/MTO. Would have done well in that role elsewhere -.as Japanese fighters had no better high altitude perormance.
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- Thread starter
- #39
2200HP means being able to carry better armerment too instead of 6x.50cal you could 8 or 6 and 2 20mms and with the A-36 being used as a bomber it would be capable of carrying a better bomb load than a allison engine version
FLYBOYJ
"THE GREAT GAZOO"
You cannot make that determination unless you do a load analysis to see if the airframe can handle the extra torque (HP) and load, let alone other structural considerations from the heaver armament. I don't think you realize that when you fire guns (or cannons) you're putting stresses on the airframe structure. Additionally you may have to strengthen structure and increase fuel capacity which means an increase in weight. You have a very simplistic approach to this - more HP doesn't always mean faster or more bombs - an old saying, you can't put 10 pounds of "poop" in a 2 pound bag!
