Best piston engine(s) for fighters of 1945?

[J.A.W.]

You are free to believe what you want.
I'm not discussing the aero engines with you anymore.

Sorry tomo, but what anyone might "believe" is surely up for review - on the basis of technical data - when it comes to engines?

I apologise if my perceived tone has ruffled certain sentiments, & ask for a 'non-feelings' - cooly technical-based discussion - in return.

 

[wuzak]

Weren't RAF Mustang IIIs V-1650-3 equipped? & the V-1650-7 was only in late production P-51B/C for the USAAF, (& D/K/Mustang IV)?
(I'd assumed the "V-1650-1" notation on the chart was an error/typo).

The chart says V-1650-7.

Regarding when the V-1650-7 was fitted to the P-51B/C or Mustang III I would have to leave to the Mustang experts.

Also, when did the RAF get the Mustang III?

Also, also, the chart also shows the Meteor III, so this chart was made no earlier than March/April 1944, and probably would have been several months later.

 

[J.A.W.]

The chart says V-1650-7.

Regarding when the V-1650-7 was fitted to the P-51B/C or Mustang III I would have to leave to the Mustang experts.

Also, when did the RAF get the Mustang III?

Also, also, the chart also shows the Meteor III, so this chart was made no earlier than March/April 1944, and probably would have been several months later.

IIRC, the RAF received an early production batch (when the USAAF still saw them as an A-36 replacement to go to 9th AAF tactical units),
& before General Doolittle had decided the Merlin Mustang was priority #1 for the 8th AAF (to which the RAF had to relinquish some).

Per the Meteor III on test, the curve shown for it - would indicate it was a real early type - before the nacelles were redesigned.

 

[EwenS]

Also, when did the RAF get the Mustang III?

65 Sqn- Dec 1943
19 sqn - Feb 1944
122 sqn - Feb 1944
306 sqn - Mar 1944
315 sqn - Mar 1944
316 sqn - April 1944
129 sqn - April 1944

In the Med
260 sqn - April 1944
213 sqn - May 1944
112 sqn - June 1944

More squadrons received them in both theatres in the second half of 1944.

The first USAAF FG with the P-51B/C was the 354th which arrived in Britain Oct/Nov 1943.

 

[J.A.W.]

65 Sqn- Dec 1943
19 sqn - Feb 1944
122 sqn - Feb 1944
306 sqn - Mar 1944
315 sqn - Mar 1944
316 sqn - April 1944
129 sqn - April 1944

In the Med
260 sqn - April 1944
213 sqn - May 1944
112 sqn - June 1944

More squadrons received them in both theatres in the second half of 1944.

The first USAAF FG with the P-51B/C was the 354th which arrived in Britain Oct/Nov 1943.

Ta for that Ewen, are those RAF dates Operational Readiness, or 1st receipt of aircraft.

What were the Mustang IIIs replacing in the ETO, not Allison-engine types, so, Spitfires?

 

[drgondog]

Weren't RAF Mustang IIIs V-1650-3 equipped? & the V-1650-7 was only in late production P-51B/C for the USAAF, (& D/K/Mustang IV)?
(I'd assumed the "V-1650-1" notation on the chart was an error/typo).

simply yes, save the P-51C-10 (Mustang III) which had the 1650-7. The early P-51D-5-NA also had 1650-3s

 

[drgondog]

IIRC, the RAF received an early production batch (when the USAAF still saw them as an A-36 replacement to go to 9th AAF tactical units),
& before General Doolittle had decided the Merlin Mustang was priority #1 for the 8th AAF (to which the RAF had to relinquish some).

Per the Meteor III on test, the curve shown for it - would indicate it was a real early type - before the nacelles were redesigned.

You are correct. The P-51B-5-NAs arrived RAF in October. Some were quickly fitted with the Hood, All sent to AAF in December 1943 when Portal responded to Arnold's plea to assist in building up the 363rd and 357th FG. Perhaps two months before Doolittle made the decision to replace P-38 and P-47s currenty in operations.

 

[EwenS]

Ta for that Ewen, are those RAF dates Operational Readiness, or 1st receipt of aircraft.

What were the Mustang IIIs replacing in the ETO, not Allison-engine types, so, Spitfires?

Those are the dates squadrons began to receive them and convert to the type.

19 & 65 flew their first Mustang sortie on 15 Feb & 122 on 25 Feb 1944. 129 & 315 flew their first sorties on 26th April 1944

19, 65, 122, 129 had been flying Spitfire IX
306, 315, 316 Spitfire Vb/Vc

In the Med 112 & 260 had been flying Kittyhawk IV & 213 Spitfire IX.

 

[hobbes154]

I'm a bit late to the party but shouldn't this have been a poll? Anyway, hard to go past Griffon or R-2800, depending on which kind of fighter you want. (V-1650-9 is also competitive up to 20k feet or so with the water injection but no better than earlier Merlins up higher IIRC?)

While I defer to Snowygrouch on the Jumo 213's advanced features, and also respect its combination of nitrous and 2-stage supercharger, I'm not sure the production quality/volume was there. (I'd interpret "for fighters of 1945" as actually entering service during that year, not prototypes. So no Griffon past 61, no "sidewinder" R-2800, certainly not the Jumo 213J or R-4360. Merlin 130-series also out.)

Edit: wherever this argument ended up with the Sabre, lack of 2-stage option rules it out as all-round best.

 

[J.A.W.]

I'm a bit late to the party but shouldn't this have been a poll? Anyway, hard to go past Griffon or R-2800, depending on which kind of fighter you want. (V-1650-9 is also competitive up to 20k feet or so with the water injection but no better than earlier Merlins up higher IIRC?)

While I defer to Snowygrouch on the Jumo 213's advanced features, and also respect its combination of nitrous and 2-stage supercharger, I'm not sure the production quality/volume was there. (I'd interpret "for fighters of 1945" as actually entering service during that year, not prototypes. So no Griffon past 61, no "sidewinder" R-2800, certainly not the Jumo 213J or R-4360. Merlin 130-series also out.)

Edit: wherever this argument ended up with the Sabre, lack of 2-stage option rules it out as all-round best.

Why does the lack of 2-stage options rule the Sabre out? How high do you want to fight, & what are you doing up there?
The Air Ministry didn't need/want a high-altitude Sabre (recall they cancelled the Mk I, capable of ~470mph @ ~25,000ft),
& almost all continued fighter vs fighter combat inevitably ended up at low-level when the engagement was prolonged...

 

[Geoffrey Sinclair]

For the Griffon, the 64 started production in June 1945, 200 built to end 1945, the 65 started production in February 1943, 1,450 built to end July 1945, the 66 started production in August 1944 and 359 built to end 1945, the 67 in June 1945 and 150, the 69 in March 1945 and 160, the 85 in November 1944 and 100, the in 87 July 1945 and 73, the in 89 July 1945 and 25 to end 1945.

The Merlin 130 began production in January 1945, 239 built by end 1945, the 131 in June 1945 and 233 built by end 1945.

Why does the lack of 2-stage options rule the Sabre out? How high do you want to fight, & what are you doing up there?

In the 20 to 30,000 feet band where the US heavy bombers operate.

The Air Ministry didn't need/want a high-altitude Sabre (recall they cancelled the Mk I, capable of ~470mph @ ~25,000ft),

That is Tempest I and Sabre IV, Napier cancelled the IV by being unable to pass the 50 hour test.

 

[J.A.W.]

For the Griffon, the 64 started production in June 1945, 200 built to end 1945, the 65 started production in February 1943, 1,450 built to end July 1945, the 66 started production in August 1944 and 359 built to end 1945, the 67 in June 1945 and 150, the 69 in March 1945 and 160, the 85 in November 1944 and 100, the in 87 July 1945 and 73, the in 89 July 1945 and 25 to end 1945.

The Merlin 130 began production in January 1945, 239 built by end 1945, the 131 in June 1945 and 233 built by end 1945.

In the 20 to 30,000 feet band where the US heavy bombers operate.

That is Tempest I and Sabre IV, Napier cancelled the IV by being unable to pass the 50 hour test.

USAAF per 8th Strategic AF under Doolittle had already decided, (& before the 2-stage Griffon Spitfire or Tempest became operational) that
he didn't even need/want any new P-47/P-38 FG's & indeed, began phasing them out, & they were the USAAF's own dedicated high altitude
fighters, in favour of the P-51B/C/D/K, so there sure wasn't any call on the RAF's fighters (except for the RAF Mustang III's of course).

The high-altitude low air-pressure oil-frothing & awry H-T ignition issues - which had arisen in the Sabre IV testing, were a factor every
high-altitude piston engine maker had to address, & Napier did likewise, (as can be evidenced - if you read the Sabre development articles
linked recently in this site) but the Air Min/RAF brass didn't need/want any new piston engine fighters, they were 'jet-bent', (again also as
previously linked/shown - via period journal articles/documentation) excepting the issue of the primitive turbines inefficiency/ fuel thirst
limiting range/endurance, esp' at low-level, thus making the retention of the best low-level, ordnance delivery capable, piston-jobs as
fighter-bombers, a needful thing - for the time being.

 

[hobbes154]

Why does the lack of 2-stage options rule the Sabre out? How high do you want to fight, & what are you doing up there?
The Air Ministry didn't need/want a high-altitude Sabre (recall they cancelled the Mk I, capable of ~470mph @ ~25,000ft),
& almost all continued fighter vs fighter combat inevitably ended up at low-level when the engagement was prolonged...

Well, this comes back to the original post: "We're probably looking at the best combination of power at all altitudes vs. the weight and size/drag penalty, with reliability as required for a service engine? Only the engines that were actually flying back in 1945."

For the Griffon, the 64 started production in June 1945, 200 built to end 1945, the 65 started production in February 1943, 1,450 built to end July 1945, the 66 started production in August 1944 and 359 built to end 1945, the 67 in June 1945 and 150, the 69 in March 1945 and 160, the 85 in November 1944 and 100, the in 87 July 1945 and 73, the in 89 July 1945 and 25 to end 1945.

The Merlin 130 began production in January 1945, 239 built by end 1945, the 131 in June 1945 and 233 built by end 1945.

Good info, not sure if they would qualify. (R-2800 was in production in 1939 but I wouldn't say it was in the running for "best piston engine for fighters of 1939"!)

 

[Simon Thomas]

When considering all altitudes, the Hercules XV had a maximum power of 1,230 hp at 38,000 ft. The R-2800-21 in the P-47 seems to be very similar at that altitude. How does these compare with other engines?
It barely squeaks into applicability, as I believe it was only fitted to three Wellingtons - two prototypes and one production. Even production might be stretching the definition a smidge.

 

[Shortround6]

When considering all altitudes, the Hercules XV had a maximum power of 1,230 hp at 38,000 ft. The R-2800-21 in the P-47 seems to be very similar at that altitude. How does these compare with other engines?
It barely squeaks into applicability, as I believe it was only fitted to three Wellingtons - two prototypes and one production. Even production might be stretching the definition a smidge.

View attachment 760221

One wonders what the actual installation looked like.
Like how big was the turbo charger and probable intercooler.

One does wonder what a 2 speed R-2800 (B-26 engine) could do with a supercharger.
The control system might have been a bit complicated to keep from over boosting the engine in high gear at certain altitudes.

 

[tomo pauk]

One does wonder what a 2 speed R-2800 (B-26 engine) could do with a supercharger.
The control system might have been a bit complicated to keep from over boosting the engine in high gear at certain altitudes.

You probably mean 'with a turbocharger (added)'?
Only the Americans were 'blocking' the engine-stage S/C in the low gear. Other people, like Japanese, Soviets or Germans were still using both S/C gears in their turbo installations (granted, these were manufactured in low numbers, but still). A combination of waste gates and throttle bodies worked there.

 

[Shortround6]

You probably mean 'with a turbocharger (added)'?
Only the Americans were 'blocking' the engine-stage S/C in the low gear. Other people, like Japanese, Soviets or Germans were still using both S/C gears in their turbo installations (granted, these were manufactured in low numbers, but still). A combination of waste gates and throttle bodies worked there.

The American system depended pretty much on the turbo controller. The pilot did not have to adjust any extra controls. Just use the throttle, at least for combat. Mixture control for cruise.
The Americans used big enough turbo to make up for the single speed supercharger on the engine at least to 25-27,000ft, It boosted the 2000ft R-2800-21 to that height.

The problem is trying to boost a two speed engine (1600hp at 13,500ft) and what happens at around 20-25,000ft?

Now maybe the Japanese, Soviets, and Germans were using smaller turbos, maybe the waste gates operated at different altitudes, conditions. Maybe the pilots had do more monitoring of the controls/systems.

 

[tomo pauk]

The American system depended pretty much on the turbo controller. The pilot did not have to adjust any extra controls. Just use the throttle, at least for combat. Mixture control for cruise.
The Americans used big enough turbo to make up for the single speed supercharger on the engine at least to 25-27,000ft, It boosted the 2000ft R-2800-21 to that height.

The problem is trying to boost a two speed engine (1600hp at 13,500ft) and what happens at around 20-25,000ft?

Problem might be if were try to gauge what other people were doing by employing American lenses.

This is what happens when a 2-speed engine gets the turbo+intercooler support (click on the thumbnail):



Ie. it makes the max SL power at almost 25000 ft. After the 2nd speed is engaged, it makes about 85% of take-off power at ~37000 ft (the non-turbo will do that at ~15000 ft, depending on the engine). Not too shabby.
Japanese were getting the similar results (percentage-wise) with the tuboed Kinseis (on the Ki-100 sibling) and, IIRC Homares (on the Saiun sibling).
Soviets were getting the similar results on the turboed AM-39s (see here).

 

[Geoffrey Sinclair]

USAAF per 8th Strategic AF under Doolittle had already decided, (& before the 2-stage Griffon Spitfire or Tempest became operational) that
he didn't even need/want any new P-47/P-38 FG's & indeed, began phasing them out, & they were the USAAF's own dedicated high altitude
fighters, in favour of the P-51B/C/D/K, so there sure wasn't any call on the RAF's fighters (except for the RAF Mustang III's of course).

The 9th AF had been scheduled to receive the P-51 units, that changed but for example the 354th FG remained with the 9th AF. On 31 January the 351st FG with P-51 went to 8th AF exchanged for the 358th FG with P-47. On 9 March 1944 the 355th FG began moving from P-47 to P-51, officially completing it a week later, thereby making the 8th AF fighter strength 3 P-38, 7 P-47 and 2 P-51 groups, there were 3 more conversions done by mid May, plus the arrival of the 339th with P-51, while another P-38 group arrived mid May. D-Day force 4 P-38, 4 P-47, 7 P-51. The P-38 were phased out July to September, then 3 of the remaining P-47 between mid September and early 1945.

The shortage of USAAF fighters saw the 9th AF units doing escort duty and the RAF helping with insertion and withdrawal cover.

The high-altitude low air-pressure oil-frothing & awry H-T ignition issues - which had arisen in the Sabre IV testing, were a factor every
high-altitude piston engine maker had to address, & Napier did likewise, (as can be evidenced - if you read the Sabre development articles
linked recently in this site)

Napier failed to get the Sabre IV to pass the 50 hour test. The Sabre V numbers seem to include a lot of conversions from mark II engines, there were 142 Tempest VI.

but the Air Min/RAF brass didn't need/want any new piston engine fighters, they were 'jet-bent', (again also as
previously linked/shown - via period journal articles/documentation) excepting the issue of the primitive turbines inefficiency/ fuel thirst
limiting range/endurance, esp' at low-level, thus making the retention of the best low-level, ordnance delivery capable, piston-jobs as
fighter-bombers, a needful thing - for the time being.

Another Napier did not fail it was stopped by outside forces and where the documents have differences to the reported conclusions. The RAF was quite aware of the early jet limitations.

Typhoons were out of service in September 1945, looks like there were 11 Tempest V fighter squadrons, 5 gave up their mark V by end 1945, 4 more in 1946 and the final 2 in February and April 1948. The 4 mark VI squadrons received their aircraft late 1946 to early 1947, giving them up late 1949 and finally March 1950. Meaning the RAF had around 6 Sabre powered fighter squadrons until April 1948. The 9 mark II squadrons all received their aircraft earlier than the mark VI squadrons, from late 1945, but did not hold onto them for as long, 3 gave the mark II up in 1946, 3 in 1947 then 1 each in 1948, 1949 and June 1951.

 

[bf109xxl]

The American system depended pretty much on the turbo controller. The pilot did not have to adjust any extra controls. Just use the throttle, at least for combat. Mixture control for cruise.
...
...Maybe the pilots had do more monitoring of the controls/systems.

You are quite right. This assumption can be confirmed by the results of the TC tests on the I-16 in 1939-1940.

PS. The cowling looks terrible...