Best piston engine(s) for fighters of 1945?

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And to put that into perspective, more modern radials require comparatively careful operation, when compared to something like a Lycoming or Continental.
Three seconds to full throttle, ensuring that the prop isn't driving the engine, etc.
FWIW, one 'fighter aircraft engine' attribute Len Setright ascribed to the Sabre, was 'its ability to blip up & down the rpm meter like a car'.
 
Any math behind this?
tomo, the remark* is supported by the Tempest's Sabre VA being capable of running at its low level normal/climb power setting for an hour,
which allows the pilot to utilize 2000+hp for that period, a quantum of power/time which the V-1650-7 powered Mustang IV can't match.

*Refers to post #34:
"...Tempest cruises effortlessy at 70mph faster than the Mustang IV."
A quote from the 213 Squadron ORB, on replacing their Mustangs with Tempests.

Edit: Noted post # for reference.
 
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I have to go with the R-2800-18W, very powerful yet compact and in combat in 1945 in the F4U-4:









 
Pretty good for an air-cooled radial (once it had received a couple of major makeovers to increase heat-rejection) but those outputs
were a tad 'ephemeral' power-setting endurance-wise. What was the R-2800 able to make in 'normal power' mode, & for how long?
 
 
Water Injection 60'' or even 70'' can be used very safely in intermitent 5 minutes periods until water is out (around 12 minutes of use).
Military 55'' 2100-1880-1700 can be used in intermitent 5-15 minutes periods, unlimited.
Normal 47-49'' 1700-1630-1550 can be used in unlimited periods.
 
Ta for that, but note the Napier Sabre VA had a 'normal' power-level of over 2,000hp, also good for as long as the fuel lasts.
 
Excellent choice, the -18W.
At 26000 ft, it was making 500 HP more than the vaunted Sabre VII.
 
Ta for that, but note the Napier Sabre VA had a 'normal' power-level of over 2,000hp, also good for as long as the fuel lasts.
Where did that come from?

Sabre power figures are all over the map.
They are worse than Merlin figures.
The Sabre VA engine didn't show up in service until about when the war ended, In Tempest VI aircraft.
There was often a considerable time between even flight test and operational/squadron use.

My summer of 1945 engine can beat your summer of 1944 engine, just like trying to use last years FI racer in this season.
A Merlin 66 in high gear only makes 1310hp at best altitude for the British max continuous rating. It also only weighed 1645lbs for a weight to power ratio of 1.25lbs/hp
The Sabre V made 1930hp at about the same altitude (both engines in high gear) but weighed about 2500lbs for weight to power ratio of about 1.29lbs/hp

Not seeing the advantage of the 1946 engine over the 1942 engine???

and if you are using 2000hp to cruise with you are landing pretty darn soon, with anyone's engine.

*Refers to post #34:
"...Tempest cruises effortlessy at 70mph faster than the Mustang IV."
A quote from the 213 Squadron ORB, on replacing their Mustangs with Tempests.
a bit of hyperbole perhaps?
or only applicable to certain conditions?

P-51D flight chart

Seems like a clean Mustang (or with bomb racks) could do 350mph at 15,000ft at a fairly economical cruise setting (middle column)
The Tempest could cruise at 420mph?
Or pick another altitude and speed like 5000ft and 340mph, Mustang is pushing it at 2700rpm and 46in but that is the limit of max continuous. Can the Tempest cruise at 410mph at 5000ft?
 
I suspect that not enough reasons existed to remotely consider replacing B-29 with the B-32.
 
Seems to me that you have missed the part concerning the valve train on the engine of Tempest II - it is, after all, the common knowledge that sleeve valves are contributing to the aircraft's performance the same way as the balkenkreutze did.
 
You can consult your Wilkinson for the Sabre VA power levels, and correlate them with the power/altitude graphs posted recently.

The Sabre VA was ~contemporary as a service engine, with the R-2800-C, but earlier Tempest units, in wartime ops also utilized the
Sabre's 'normal/climb' power setting for 'armed recce' fighter interdiction sweeps, in fact one Wing Commander (Flying) J.B. Wray,
(who did 'bag a brace' of Me 262s) was nicknamed "45 minute Wray" for his method of doing so.

R. Beamont another Tempest Wingco described a fast cruise speed of "365 IAS" at tactical heights*, & J. Sheddan a veteran 486 NZ Sqd
pilot who'd flown numerous op sorties in both Typhoon & Tempest even remarked that sometimes they'd deliberately do a slow cruise
which the Tempest pilots hoped would make the LW controllers think them to be lesser foes to take on, & so "send up some trade".

*8-10,000ft, 'where the light flak was curling under beneath, & below useful height for the heavy stuff, yet still with a good view'.
 
Seems to me that you have missed the part concerning the valve train on the engine of Tempest II - it is, after all, the common knowledge that sleeve valves are contributing to the aircraft's performance the same way as the balkenkreutze did.
Well, certainly in efficiency terms, ex-Spitfire ace & Hawker test pilot Neville Duke flew a delivery flight across to the Middle East in a Hawker
fighter equipped with a Centaurus mill postwar, & on the London-to-Rome 1st leg - duly beat the speed/distance record only just set -
by the DH Vampire turbo-jet!
 
People that were flying P-82s didn't gotten them memo that said 'either sleeve valves or nothing' when they were making record-setting flight of 5000+ miles non-stop.
 
People that were flying P-82s didn't gotten them memo that said 'either sleeve valves or nothing' when they were making record-setting flight of 5000+ miles non-stop.
They never had the option, did they? (That P-82 Betty-Jo, must've been loaded with almost as much gas as a late-model P-47!).

Given the Tempest test-flight report written by the USAAF in late 1943 - they'd have liked to have a reverse Lend-Lease option - on it.

 

Here's an informative piece on how Chrysler Corp dealt with Wright engines under the pressure of the top priority B-29 program:


Note the comments about how the R-3350 "...often ingested its own valves", but hey - they were poppets, not sleeves...

Edit: fixed typo.
 
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Check the Sabre's 'max climbing' (~'normal) power/height line graphed in the attachment linked below.

Sabre makes over 2,000hp from S-L to 12,000ft & over 1,900hp on up to 19,000ft at 3,700rpm/+10.5lb boost.

Sabre VII is 'wet' variant of Sabre VA, but the ADI wasn't used at those power settings.

Edit 1: guess another issue to work out would be the old IAS or TAS question?

Edit 2: The chart below shows how ^ boosting the Sabre & the speed increase in Tempest,
duly noting that this was early 1944, & max-boost then - became a 'normal' setting by 1945.

 

Attachments

  • Napier Sabre VII Flight 1945 a (1).pdf
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I am looking, I have also looked at the Griffon 69 mentioned on the page 4 of attachment. 2375hp.

What it rather interesting is that 2130hp is claimed at 15,500ft while the Sabre engine is about 2450hp at the same altitude on the graph in the article.
At 21,000ft the difference in power is a lot closer. The Griffon engine is over 450lbs lighter and the article claims a specific weight of 0.88lb/hp (low gear, max boost)
The specific weights I gave earlier were for max cruise.

edit. a lot of these engines have specs that bounce all over the place depending on when the specs were quoted. The Article explains rather well the differences between the late model Sabres and the earlier ones, there was a lot more than just screwing around with the boost settings
Even the article on the Griffon engine is about the changes in the power listed from an earlier article.
 
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