The German Griffon showed what happens when pie-in-the-sky tactics are applied to a warplane.
German Griffon - the Heinkel He 177 Grief?
What was pie in the sky about that? Other than the requirment to be able to dive bomb.
Poor execution does not make it pie in the sky.
I read the original post and all the supposed great leaps and bounds are simple hot rod think which does not apply to aircraft engines, PERIOD.
There would be gains obviously but not even remotely close to the pit-in-the-sky gains some here think would happen.
A lot of the suggestions here are extensions of the proposal Tresilian put forward in 1945 - a 10.3l X-16 that makes as much power as the Griffon using revs and big boost. Most of the suggestions centre around direct fuel injection, other forms of efi and improvemnets to materials, engine design and production techniques.
A clean sheet engine would would be an improvement with survivability the number one concern regardless of power output.
Performance is, perhaps, the biggest part of surviveability.
The Sabre like the Centaurus were sleeve valve.
The main reason they are not up rated for Reno is lack of return for investment to allow them to go head to head with the poppet valve engines.
Or, simply, a lack of engines. There are no flyable Sabres in the world, as far as I am aware. There are only a handful of Centauruses (Centauri?).
The Sabre had 24 cylinders, if they were not smaller than those of a Merlin it would have been a huge engine.
It was 82 by 40 2360 lbs, and Merlin is 88 by 30 1640 lbs, and Griffon is 81 by 30 1980 lbs
You need the full dimensions. The Sabre was 46" high x 40" wide x 82" long (some later Sabres were taller still, around 47-48"). Depending on version Sabres could be as much as 2550lb.
The Griffon (2 stage) engine was 46" high x 30" wide x 81" long. 1980lb.
The Merlin (2 stage) 40" high x 30" wide x 88" long. 1650lbs, depending on accesories.
The Wright R-3350 was 56" in diameter, and 77" long.
During WW2 the R-3350's maximum rating was 2200hp.
The Sabre IIB was rated at 2400hp and maximum continuous of 2065hp @ 4750ft. The Sabre V was evolved by 1944 and had a combat rating of 2600hp, and a maximum continuous of 2165hp. In 1944 the Sabre was probably more reliable than the R-3350. The Sabre VII was combat rated for over 3000hp just post war, and 2235hp max continuous. With ADI, takeoff power was 3500hp.
Eventually the R-3350 was brought up to around 2800hp maximum, and up to 3700hp in turbo-compound form (but also much heavier).
To put that in perspective, in 1944 the R-4360 was rated at 3000hp for around 3800lbs. Post war it was uprated to 3500hp. The most it got (without the "pie in the sky" VDT versions) was around 3700-3800hp.
Meanwhile Sabres had tested, comfortably, to over 4000hp.
Fuel consumption for Sabre max cruise 117 gph, Merlin 88 gph.
What is the specific fuel consumption. At max power a Merlin would be around 0.60-0.65lb/hp/hr, or worse.
And what actual power output at that gph reading? 2600hp for the Sabre vs 2000hp for the Merlin?
For the weight and hp of a Sabre one could use a R 3350 which weighs 2670 has higher hp with less complexity, and greater chance to survive battle damage, so the Sabre has no real advantages.
A) The R-3350 didn't have more power than the contemporary Sabre.
B) The installed weight of the Sabre would undoubtedly be more. The power to installed weight would be similar.
C) The Hawker Tempest used both the Sabre and the Centaurus, the latter being similar in capacity and size to the R-3350. The Tempest II (Centaurus) outperformed the Tempest V (Sabre IIB, V, VI or VII). The engine power was similar. The problem was that the chin radiator was not very good for drag. The Tempest I (Sabre IV, leading edge radiators) had less power than the Tempest II, but was significantly faster. Similarly, the Hawer Fury prototype fitted with Sabre and annular radiator was faster than when fitted with the Centaurus.
D) A Sabre fitted in an aircarft designed around the Centaurus had space to spare.
E) The advantage the Sabre had over the R-3350 was mainly power. In late WW2 the Sabre was capable of continuous power nearly equal to or exceeding the maximum power of the R-3350.
As an aside, the Vulture had tested on the bench at 2500hp before its cancellation. So, before 1941. It weighed 2450lb, but had production continued the reduction gear would have been redesigend for considerable weight savings (c. 200lb).