Jumo 213 vs. Napier Sabre

spicmart

Senior Airman
684
114
May 11, 2008
Being the peak engine developments of their specific countries which one was more modern, had more potential, was more efficient, more powerful, overall better?
 
Last edited:

tomo pauk

Creator of Interesting Threads
12,840
3,613
Apr 3, 2008
Sabre was more modern, not that that was automatic win for it (it probably gave a lot of trouble for being very modern engine), while Jumo 213 was very 'classic' engine pushed to the limit.
Sabre also have had more potential, the margin might be not that great, though.
Efficient - in sense of fuel mileage, or in sense that it excelled in it's job, or what one gave better bang for buck? Jumo 213 will be easier and cheaper to make, probably will have better mileage, however Sabre was making better power and was in service much easier, even if we remove the 1942, the year of Sabre's troubles.
Sabre was probably overall better, by virtue of serving much longer than the Jumo 213 while making better power.

Before people start yelling 'what about the 213E and F' - all good, but too late. The 213J was even a greater engine, but it missed usage in the ww2.
 

Shortround6

Major General
19,778
11,760
Jun 29, 2009
Central Florida Highlands
Kind of leaves out the Griffon.
It also leaves out two important considerations.
Initial cost (Sabre is higher) and engine life/time between over hauls.
The French were still trying to flog the Jumo 213 to potential customers in the early 50s but that was because they had inherited a bunch of tooling and parts and didn't have much of their own to compete with it. Sabre was long gone.
 

Shortround6

Major General
19,778
11,760
Jun 29, 2009
Central Florida Highlands
The French version was advertised at 2300hp for take-off using 100/130 and water injection and 2100hp dry.
It also weighed 2100lbs. or about 400lbs less than the last Sabres. It was supposed to offer about 10% less fuel burn per hp (but a at a lower power rating) but some of the published fuel burns for several engines may be a bit off.
 

spicmart

Senior Airman
684
114
May 11, 2008
Sabre was more modern, not that that was automatic win for it (it probably gave a lot of trouble for being very modern engine), while Jumo 213 was very 'classic' engine pushed to the limit.
Sabre also have had more potential, the margin might be not that great, though.
Efficient - in sense of fuel mileage, or in sense that it excelled in it's job, or what one gave better bang for buck? Jumo 213 will be easier and cheaper to make, probably will have better mileage, however Sabre was making better power and was in service much easier, even if we remove the 1942, the year of Sabre's troubles.
Sabre was probably overall better, by virtue of serving much longer than the Jumo 213 while making better power.

Before people start yelling 'what about the 213E and F' - all good, but too late. The 213J was even a greater engine, but it missed usage in the ww2.
Calum Douglas stated that the Jumo 213J would have probably been the best piston engine of the war. Coming from such an expert where does that leave the Sabre? Figures I've seen for both seem to favor the Napier product though , as you said.
 
Last edited:

spicmart

Senior Airman
684
114
May 11, 2008
The French version was advertised at 2300hp for take-off using 100/130 and water injection and 2100hp dry.
It also weighed 2100lbs. or about 400lbs less than the last Sabres. It was supposed to offer about 10% less fuel burn per hp (but a at a lower power rating) but some of the published fuel burns for several engines may be a bit off.
How do the power-to-weight-ratios of the two compare?
 

tomo pauk

Creator of Interesting Threads
12,840
3,613
Apr 3, 2008
Calum Douglas stated that the Jumo 213J would have probably been the best piston engine of the war. Coming from such an expert where does that leave the Sabre? Figures I've seen for both seem to favor the Napier product though , as you said.
Sabre was flying dangerous missions during during the 3 years of war.
Jumo 213J flew zero missions.
Question should be: where does that leave the 213J?
 

SaparotRob

Unter Gemeine Geschwader Murmeltier XIII
8,735
8,099
Mar 12, 2020
Long Island, NY
As Snowy Grouch might say "would have probably been the best..." The musings of an engineer?
 

GTX

Master Sergeant
2,378
6,851
Dec 18, 2015
I would have thought some of the Argus engines would be more of a comparison to the Sabre:

 

Macandy

Senior Airman
371
269
Aug 6, 2017
Sabre was a terrible engine, the RAF was very glad to be rid of the relentlessly troublesome creature
 

cherry blossom

Senior Airman
449
313
Apr 23, 2007
Since this is partially a thread on the Jumo 213, I thought that I would ask if anyone knows why it took such a long time to make the Jumo 213 into a reliable engine.

Calum writes on page 220 "On March 14 1941, the Jumo 213 A-0, No. 13 reached 2110bhp at 3200rpm at 1.74 atmospheres manifold pressure" and goes on to note the excellent fuel consumption at lower power (referenced to IWM, GDC-Collection, GDC-17-12T - "Tests of Jumo 213 Aero-Engines", English Translation 1943 pg 8).

An online article Junkers Jumo 213 by Doug Culy adds "It is known to have been running by the start of 1938 [Green, 1979], and was first flown in Ju 88B V-28 before July 1941 [Kay, 2002]"

Now we know one major problem that was discussed at enginehistory.org V-12 Firing Order Display "The three examples (213, 213 with Rechlin order, and 213E) show how changes in firing order made a reliable engine out of one that was breaking crankshafts. The problem was too many torque reversals per cycle. This was cured in the 213E by choosing a firing order that systematically loaded and then unloaded the crankshaft."

My problem is that I have not been trained to design V-12 aero-engines and thus I do not know why the original firing order was chosen (well it was used in the Jumo 211, so I sort of do) and why it took two years to be identified as a problem. Presumably the firing order is also chosen to give the best "breathing" by not firing neighbouring cylinders one after the other. Can anyone else say what happened during the Jumo 213 development?
 
Last edited:

Snowygrouch

Senior Airman
732
2,015
Dec 28, 2015
Scotland
www.facebook.com
It didn't, really take "such a long time". the Merlin for example was a pile of garbage for nearly half a decade from the point when drawings began to when the resulting engine was in any way reliable or decent (see ramp head). It just took about five years to get a new aero engine successfully into mass production from design.
 

spicmart

Senior Airman
684
114
May 11, 2008
The original question perhaps needs a little parsing. You either need to pick a point in time, and say on THIS date, which one was at a greater level of technological development and war potential, or, dispense with any semblance of history, and say, "here are both engines, new in boxes, unpack them and critique them today".

I tend to the latter.
At war's end can you determine roughly the development potential inherent in both designs and what could be expected in terms of development potential for the post-war years. Also rate them in regard to engine development until today.
 

Snowygrouch

Senior Airman
732
2,015
Dec 28, 2015
Scotland
www.facebook.com
Well I wrote a sizable book which already explains it in quite some detail.
But broadly sleeves had reached the limit of boost and been found wanting (big problems with liner distortion and also thermal issues due to the obviously
appalling conductivity through the sleeve. I dont think you`ll ever get more than was gotten from the Sabre with water injection.

Jumo 213 only became superlative with the 4-valve head, although it was already drastically more advanced than the Merlin (until the 100 series) in most respects (water cooled
exhaust valve guides, swirl throttle, crankshaft nose oil feel, oil centrifuge and so on. All of which are on all Formula One engines on the grid right now (although Renault used
to make do without a centrifuge, by having a bigger and more complex oil tank, but they probably have a centrifuge now).

Broadly the 213 reached about the same max boost pressure as the Sabre throughout the war but on 87 Octane fuel. Which is quite extraordinary
and shows how much better the cooling of the combustion chamber/piston/bore walls must have been. The Sabre made decent power but
at least in part by running at high rpm. The 213J ran only 300rpm slower and "apparently" was planned to exceed 4000rpm eventually. Which I can
believe looking at the internal parts (much lighter than 213A).

As far as comparisons to today, as far as I know except for some novelty engines which don't appear to be used for much, nobody is using sleeves for anything.

As I said, every F1 engine on the grid has virtually every major design aspect of the 213.

The 213 has a pretty quirky design for the liner attachment which I don't think I`d use myself, but otherwise, if I were to design an aero engine now,
I`d pretty much scale down a 213J and maybe just opt for a Merlin 2-piece block sandwiched liner attachment.

Sabre was definitely obstructed and strangled by people at RR and the Air Ministry (F. R. Banks), but, was basically a very expensive and mostly unreliable novelty
which was in hindsight, the wrong technical path. The component design is very good, but the sleeve concept was a mistake. Quite possibly a poppet
valve Sabre would have been quite a hard thing to beat.

The 213 pointed to the future in nearly every respect, and aside from the slightly odd liner clamps, and in "J" form, is vastly technologically superior in general concept to
anything else which flew in combat in WW2. The power it extracted from bog standard B4 fuel is quite remarkable, if you were to downrate Allied engines to run on
87 octane, nothing would have been close to a 213 on a per-litre basis. Wartime problems, materials shortages, fuel shortages and so on together with the significant failure to
get a 4-valve head into combat production on the 213 prevented it from becoming a world-beater. Its an unbelievably advanced engine in concept, an entire generational leap
ahead of the DB600 series.
 

BarnOwlLover

Airman 1st Class
212
54
Nov 3, 2022
I usually favor engines like the Merlin because of it's efficiency and size as shown in the Mustang (I doubt a P-51 with a Griffon would've been much better aside from maybe being a better interceptor, which most versions of the Mustang that made it into production weren't optimized as except the P-51H, and even that was primarily intended to be an escort fighter).

And I do appreciate the fact that engines like the ultimate developments of the Merlin eventually were capable of making 2600+hp. However, that was with 150 octane fuel, ADI, 3300 rpm and 36 lbs of supercharger boost. Essentially, it was a WEP/sprint rating. The RM.17SM was intended to be rated 2380hp for take off and 2200 normal max power.

And there was a big caveat with the Allison V-1710s of late production (like those fitted to the F-82 Twin Mustang)--it was capable of making two-stage Merlin levels of power, but it wasn't quite as powerful overall in actual service or efficient or did as well at higher altitudes. Above all, though, they weren't particularly reliable vs the Merlin. Fouled spark plugs, burnt valves and pistons and supercharger problems were fairly common if the engines weren't well maintained, and they needed a lot of maintenance.

A lot of this was GM's and Allison's bullheaded-ness concerning how to built an engine with a two-stage supercharger. North American and even the USAAF/USAF used ideas that worked on the Merlin to make the engines more powerful and reliable, but Allison and GM bushed them aside. It's worth noting that North American was part-owned by GM until 1948, and with no World War II going on, the USAAF/USAF and the US Gov't didn't have the power (or at least the will) to bully and brow-beat GM into accepting those solutions like what happened with the Merlin Mustangs during World War II. Those factions also weren't helped by the fact that Packard ended mass production of the Merlin shortly after World War II, Rolls-Royce wanted the US Gov't to pay a $6000 licensing fee per engine that was waived for most of World War II due to Britain's economy being in the crapper, no huge military demand for piston engines (be it Merlin or Griffon), and dealing with the lag time/transition to jets for military and ultimately civil use. And importing engines from R-R wasn't an option, either, as they'd charge and arm and a leg for them for the reasons stated above.
 

Users who are viewing this thread