Why inverted-V engines in German WWII aircraft?
Geoff May
I'm trying to find out *why* the inverted-V engines were so popular in WWII
aircraft, (specifically German). Can someone tell me what
advantages/disadvantages the inverted-V had as compared to normal V engines?
Also, are there any current inverted-V engines, (any application, not
specifically aircraft)?
I realise that the last is could be a bit off topic but would be interested
to know if there are still inverted-V engines in use somewhere...
MfG
Geoff.
--
"Sage nicht immer, was du weißt, aber wisse immer, was du sagst." - Matthias
Claudius
"If you haven't got anything to say, don't say it." - My mother.
Clinton Bowen
with garvity.
"Geoff May" <Geof...@doka.de> wrote in message
news:3b78ff41$0$241$4dbe...@businessnews.de.uu.net...
Ralph Savelsberg
> i'm no expert on engines but me brain says more HP if pistons are helped
> with garvity.
I don't think that is very likely, although I'm not a specialist on engines
either. The reason why I think that your explanation isn't correct is that
at the time a number of the pistons are travelling downwards, being helped
by gravity, the same number of pistons is travelling upwards, against
gravity. Inverting the engine doesn't change that.
I don't know the particular reason, but one thing I could think of is that
it could have to do with accessability of the pistonheads and fuellines
from the ground. I could imagine those being closer to the ground than in
an upright V-engine, perhaps easing maintenance. This doesn't seem enough
of a reason though.
Regards
Ralph Savelsberg
JDupre5762
>aircraft, (specifically German). Can someone tell me what
>advantages/disadvantages the inverted-V had as compared to normal V engines?
One reason but not the only one is to lower the profile of the engine cowling
in relation to the windshield. With the engine inverted there is less to
block the view of the pilot allowing a better view forward when taxiing and
flying. This is a real consideration for tailwheel airplanes. Another point
is it can be easier to align the thrust line of the engine with the center of
the airframe but this also depends on the airframe configuration.
In the U.S. and the U.K. and Germany by the 1930's most of the in line engines,
as opposed to V type, were inverted i.e. Ranger, Menasco, Gypsy, and Hirth etc.
but with more than six cylinders this made the engines extremely long so to
make a more compact engine the V configuration was used. Ranger built an
aircooled inverted V-12!
Abover 400 HP the U.S. and the U.K. tended to go with radial engines but the
Germans went to the V type aircooled.
I have seen several Fiesler Storchs and Bf-108's still flying with the Argus
V-8 over the years but none are now in production.
John Dupre'
Martin Winchester
The way I understood it was that a delegation from germany around 1935/36
visited Rolls Royce, and saw an early Merlin.
The engine was inverted while being worked on. Nobody bothered to tell the
Germans this and they left under the impression that RR were working on an
inverted V12. This then spured them into developing inverted engines... and
the rest is history...
This story may be an urban myth... so don't shoot me down please......!
Zeb
Keith Willshaw
"Martin Winchester" <zeb...@giberish.hotmail.com> wrote in message
news:9lb62b$ah0$1...@oceanus.connect.org.uk...
Its hogwash
The Germans were building inverted Vee engines
in the 20's and had no need to copy anyones designs
since their engines were if anything more advanced
For example their use of fuel injection gave the Luftwaffe
a considerable advantage in the early part of the BOB
Plenty of engines were inverted vee including American
in lines like the Continental XIV-1430-3
Keith
Emmanuel Gustin
> I'm trying to find out *why* the inverted-V engines were so popular in WWII
> aircraft, (specifically German). Can someone tell me what
> advantages/disadvantages the inverted-V had as compared to normal V engines?
The motivation appears to have been, basically, better view over the nose
than with an 'upright' V-12. Maybe better compatibility with an elliptical
fuselage cross-section was also a factor.
Emmanuel Gustin
Ron Miller
: One reason but not the only one is to lower the profile of the engine cowling
: in relation to the windshield. With the engine inverted there is less to
: block the view of the pilot allowing a better view forward when taxiing and
: flying. This is a real consideration for tailwheel airplanes. Another point
: is it can be easier to align the thrust line of the engine with the center of
: the airframe but this also depends on the airframe configuration.
That's got to be it. It aligns the crankshaft centerline high on the axis
of the aircraft giving prop clearance. (And at the time ALL fighters were
tailwheel airplanes except for a few oddballs)
It's a design nuisance though because you need to scavenge the oil from the
crankcase to keep windage losses down and you have do a pull-thru before
start to ensure no hydro-lock has occurred.
Ron
Peter Stickney
"Keith Willshaw" <keith_w...@compuserve.com> writes:
>
> "Martin Winchester" <zeb...@giberish.hotmail.com> wrote in message
> news:9lb62b$ah0$1...@oceanus.connect.org.uk...
>> Ok.... this story might be aprocafull... i'm not sure but here goes...
>>
>> The way I understood it was that a delegation from germany around 1935/36
>> visited Rolls Royce, and saw an early Merlin.
>> The engine was inverted while being worked on. Nobody bothered to tell the
>> Germans this and they left under the impression that RR were working on an
>> inverted V12. This then spured them into developing inverted engines...
> and
>> the rest is history...
>>
>> This story may be an urban myth... so don't shoot me down please......!
I Concur. There are enough other characteristics about the Merlin, or
any other engine, that would tell any competent observer that it's
just a regular engine upside-down. However, Rolls did do some studies
on inverted-vee engines.
>
> The Germans were building inverted Vee engines
> in the 20's and had no need to copy anyones designs
> since their engines were if anything more advanced
On that I don't agree. The German inline engines tended to be huge
honkin' pieces of metal, with rather poor Specific Power (HP/swept
volume) While they had some neat ideas, lie the oil-driven variable
speed superchargers of the DB601 and DB605, they also had a lot of
problems gettig it to work right, especially in the field.
Daimler-Benz and Messerschmitt went 'round and 'round on that for
years. (It seems that the supercharger drives were failing due to
cavitation if the oil. Messerschmitt kept telling Daimler that it was
an oil pump probkem. Daimler kept insisting that the problem was
Messerschmitt's design of the oil tanks.) They also didn't get the
same supercharger efficiencies, which led to such expedients as
Nitrous Oxide injection to improve the critical altitude of the
engine. (That's the sort of thing you do when other options are no
feasable.)
The BMW 801 was a fantastic bit of machinery, though.
>
> For example their use of fuel injection gave the Luftwaffe
> a considerable advantage in the early part of the BOB
At a cost in other areas. It turned out that the best solutions were
the Bendix-Stromberg or Chandler-Evans Pressure Carburetors, which
injected fuel into the airstream upstream of teh engine-stage
supercharger, giving a lot of charge cooling, and even mixture
distribution via the supercharger itself, or the NACA Injection
Impeller, ehich used the supercharger impeller to distribute fuel,
with the same advantages.
The Germans weren't foolish or stupid, but I see their inlines as
suffering from "Creeping Featuritus", as their most distinguishing
characteristic.
--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster
Steven P. McNicoll
"Ron Miller" <r...@fc.hp.com> wrote in message
news:9lbas0$g5k$1...@fcnews.fc.hp.com...
>
> That's got to be it. It aligns the crankshaft centerline high on the axis
> of the aircraft giving prop clearance. (And at the time ALL fighters were
> tailwheel airplanes except for a few oddballs)
>
That would certainly be true of direct-drive engines, but these engines were
geared, propeller shafts turned at about half the speed of the crankshaft.
In upright V engines the propeller is above the crankshaft, in inverted V
engines the propeller is below the crankshaft.
Gord Beaman
Not necessarily Stephen, the gearbox can usually be mounted
either way to accomodate the prop. For instance on the Aurora and
the Convair 580 the propshaft is above the engine input shaft to
allow prop ground clearance while with the same engine and
gearbox the C-130's propshaft is 'below' the engine input shaft.
(their gearbox is 'upside down' :)).
--
Gord Beaman
PEI, Canada
Gord Beaman
Steven P. McNicoll
"Gord Beaman" <gbe...@islandtelecom.com> wrote in message
news:3b7997f1...@news1.islandtelecom.com...
>
> Not necessarily Stephen, the gearbox can usually be mounted
> either way to accomodate the prop. For instance on the Aurora and
> the Convair 580 the propshaft is above the engine input shaft to
> allow prop ground clearance while with the same engine and
> gearbox the C-130's propshaft is 'below' the engine input shaft.
> (their gearbox is 'upside down' :)).
>
The aircraft you mention are all turbines, we're talking about piston
engines.
Gord Beaman
Steven P. McNicoll
>
> Which has what to do with engine/prop placement?.
>
I suggest you engage your brain, then review the thread.
Gord Beaman
Steven P. McNicoll
>
> Couldn't think of a good reason right?.
>
Didn't review the thread, right?
Gord Beaman
I certainly bloody well DID review it sonny...it starts off with
someone asking why inverted V engines versus upright V engines...
-Someone suggests 'maybe gravity?'...
-Someone shoots that down and counter suggested, maybe ease of
maintenance?...
-Someone suggested maybe better visibility?...
-Someone else agreed with that...(me too btw)...
-YOU mentioned gearboxes...seeming to suggest that gearboxes
would somehow defeat the visibility advantage of the invert.
-I then mentioned that gearboxes could be mounted upright or
inverted. (therefore shooting your theory down)
-You then came out with the gem that "We're discussing recips,
here, not turbines".
-I asked why the ENGINE TYPE matters....
-YOU couldn't answer that so reverted to insults...etc...
That about sum it up?...(careful now, we're out in public here!)
:)
Tony Williams
Apart from the effect on the aerodynamics of having the gearbox stuck
outside the frontal area of the engine, that wasn't really an option
with some German installations (eg Bf 109) which required an
engine-mounted cannon to fire through the propeller hub.
Tony Williams
Author: Rapid Fire - The Development of Automatic Cannon, Heavy
Machine Guns and their Ammunition for Armies, Navies and Air Forces.
Details on my military gun and ammunition website:
http://www.users.globalnet.co.uk/~autogun/
Gord Beaman
--cut--
>> >
>> Not necessarily Stephen, the gearbox can usually be mounted
>> either way to accomodate the prop. For instance on the Aurora and
>> the Convair 580 the propshaft is above the engine input shaft to
>> allow prop ground clearance while with the same engine and
>> gearbox the C-130's propshaft is 'below' the engine input shaft.
>> (their gearbox is 'upside down' :)).
>
>Apart from the effect on the aerodynamics of having the gearbox stuck
>outside the frontal area of the engine, that wasn't really an option
>with some German installations (eg Bf 109) which required an
>engine-mounted cannon to fire through the propeller hub.
>
>Tony Williams
Well, yes Tony, for such specialized installations as those a/c
requiring a gun to shoot through the hub I'd think that a gearbox
would be the 'only' route wouldn't it?. How else could you get
the prop hub centerline 'above or below' the crankcase?. Besides,
the C-130 and the P-3 are certainly proven airframes which don't
seem to suffer much by using this kind of gearbox.
Emmanuel Gustin
> Which has what to do with engine/prop placement?.
The main working parts of turbine engines have to be
symmetrical, or disaster will certainly follow.
On a V-12 engine the logical arrangement for the gearbox
is to put it in line with the gap of the 'Vee', to stay within
the fuselage contours defined by the engine, have stronger
attachment points for the gearbox, and even out the loads
on the engine attachment points. It would be technically
possible to put the gearbox of a V-12 below the crankcase
or that of an inverted V-12 above the crankcase, but I don't
know any example of such an outrageous design.
--
Emmanuel Gustin <gus...@NoSpam.uia.ac.be>
Military Aircraft Database: http://www.csd.uwo.ca/~pettypi/elevon/
(Delete NoSpam. from my address. If you can't reach me, your host
may be on our spam filter list. Check http://www.uia.ac.be/cc/spam.html.)
Cub Driver
>The Germans were building inverted Vee engines
>in the 20's and had no need to copy anyones designs
>since their engines were if anything more advanced
Didn't the first 109 to fly have a British engine in it?
Or maybe it was a 108. But it seems to me that the British and the
Germans were selling each other engines in the 1930s.
all the best -- Dan Ford (email: let...@danford.net)
see the Warbird's Forum at http://danford.net
and message board at http://forums.delphi.com/annals/start/
Geoff May
Thanks.
Basically what you appear to be saying is that the inverted-V's were used
because:
1) Ease of maintainance, (you could reach most of the engine without
using ladders etc.), and
2) Better view over the cowling, very important in both taxiing and
dog-fighting.
Basically, there was no particular reason because of better/improved
performance then?
MfG
Geoff.
Gord Beaman
--cut--
>"Gord Beaman" <gbe...@islandtelecom.com> wrote in message
>news:3b79b83d...@news1.islandtelecom.com...
>
>> Which has what to do with engine/prop placement?.
>
>The main working parts of turbine engines have to be
>symmetrical, or disaster will certainly follow.
>
C'mon Emmanuel, do you really believe that?...look at the Allison
T-56 engine and gearbox installation on the C-130 Hercules. The
gearbox offsets the propshaft from the turbine/compressor shaft
by a large amount below it. Now look at the same engine and
gearbox on the P-3 Aurora/Orion, exactly the same engine with the
same gearbox mounted ABOVE the turbine/compressor shaft. Not too
symmetrical one would think. Gee.
Gord Beaman
My vote goes to nr 2 Geoff, better vis, but then I was never a
fighter pilot during the war...just a gut feeling (and I'm well
qualified in that dept.!) :)
Emmanuel Gustin
> >The main working parts of turbine engines have to be
> >symmetrical, or disaster will certainly follow.
>
> C'mon Emmanuel, do you really believe that?...look at the Allison
> T-56 engine and gearbox installation on the C-130 Hercules. The
> gearbox offsets the propshaft from the turbine/compressor shaft
> by a large amount below it.
The core of a turbine engine is by definition highly symmetric.
There is nothing to it that forces the engine designer to prefer
a location for the gearbox and propeller shaft. Therefore, other
factors are decisive. (If the gearbox is not simply put in line
with the turbine shaft).
The "core" (that is an anachronism, I know) of a V-12 engine
is by definition highly assymetric. The natural tendency
and logical choice for any designer is to use the gearbox
to restore some symmetry by bringing the thrust line closer
to the center of mass and the geometric center of the engine.
What's the problem?
Gord Beaman
>is by definition highly assymetric. The natural tendency
>and logical choice for any designer is to use the gearbox
>to restore some symmetry by bringing the thrust line closer
>to the center of mass and the geometric center of the engine.
>
>What's the problem?
>
>--
inverting the engine (likely for visibility concerns) and someone
mentioned gearboxes offsetting the propeller and that being a
disadvantage, I then pointed out that the gearbox could be
arranged as it is on some turboprops. This seemed to upset
someone.
In any case, your suggestion that the gearbox should provide
symmetry to the thrust line seems a very small point to me. Sure,
if it's not detrimental in any way then ok, but the very
asymmetric design of the Allison T-56 and it's gearbox is proof
positive that the symmetry of these two units is somewhat
unimportant in a practical sense.
Tarver Engineering
I would suspect orientation of the gearbox would be more a mechanical
clearance issue.
John
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Peter Stickney
"Geoff May" <Geof...@doka.de> writes:
> Basically what you appear to be saying is that the inverted-V's were used
> because:
>
> 1) Ease of maintainance, (you could reach most of the engine without
> using ladders etc.), and
I'm not totally convinced of that. The lubrication system's more
complicated, and the ease of getting to the cylinder heads is
mitigated by the need to get in there more often, because of the
effects of having the engine oil getting into the heads. Radials are
bad enough, with only a few cylinder pointing down!
>
> 2) Better view over the cowling, very important in both taxiing and
> dog-fighting.
>
> Basically, there was no particular reason because of better/improved
> performance then?
No, not really. It was a style thing, I'd say. Fashions exist in
aircraft design, too. On a "visit your local airport" level,
there wasn't any particular reason for Cessna to switch to those swept
vertical stabilizers in the late '50s/early '60s, or for Piper to
start putting T-tails on all their singles. (Warrior, etc.)
Tarver Engineering
"Peter Stickney" <p-sti...@worldnet.att.net> wrote in message
news:832el9...@Mineshaft.att.net...
> In article <3b7a6f25$0$238$4dbe...@businessnews.de.uu.net>,
> "Geoff May" <Geof...@doka.de> writes:
> > Basically what you appear to be saying is that the inverted-V's were
used
> > because:
> >
> > 1) Ease of maintainance, (you could reach most of the engine without
> > using ladders etc.), and
>
> I'm not totally convinced of that. The lubrication system's more
> complicated, and the ease of getting to the cylinder heads is
> mitigated by the need to get in there more often, because of the
> effects of having the engine oil getting into the heads. Radials are
> bad enough, with only a few cylinder pointing down!
Radials tended to be total loss oil systems, so there was no return problem.
Using vacuum to return oil from inverted engines is not really a complicated
problem, other than temperature.
Bertie the Bunyip
>
>"Peter Stickney" <p-sti...@worldnet.att.net> wrote in message
>news:832el9...@Mineshaft.att.net...
>> In article <3b7a6f25$0$238$4dbe...@businessnews.de.uu.net>,
>> "Geoff May" <Geof...@doka.de> writes:
>> > Basically what you appear to be saying is that the inverted-V's were
>used
>> > because:
>> >
>> > 1) Ease of maintainance, (you could reach most of the engine without
>> > using ladders etc.), and
>>
>> I'm not totally convinced of that. The lubrication system's more
>> complicated, and the ease of getting to the cylinder heads is
>> mitigated by the need to get in there more often, because of the
>> effects of having the engine oil getting into the heads. Radials are
>> bad enough, with only a few cylinder pointing down!
>
>Radials tended to be total loss oil systems, so there was no return problem.
>Using vacuum to return oil from inverted engines is not really a complicated
>problem, other than temperature.
Bwawhahwhahwhhahwhahwhahwhahhwhahwhahwhhahwhahwhahhwhahwhahw!
Total loss oil systems?
Bwahwhahwhahwhahwhahwhahwhahwhhahwhahwhahwhahhwhahwhahwhahwhahhwahwh!
Is ther anything related to aviation that you know anything about?
Bertie
www.nzherald.co.nz/storydisplay.cfm?thesection=business&thesubsec
tion=&storyID=168118
Offensive intruder poisons chat lines
12.01.2001 By MICHAEL FOREMAN
Local internet service providers may consider blocking an American from
taking part in online discussions following one of the worst cases of
"flaming" seen in this country.
A mysterious figure calling himself "Bertie the Bunyip" has upset local
Usenet newsgroups after a bizarre campaign that has included posting
fake photographs of a topless Queen Mother.
If someone burst into a cafe or pub and started yelling obscenities and
abusing everyone in sight, you might expect the manager to throw them
out or call the police.
But neither of these remedies is available to the newsgroup users, who
are desperate to rid themselves of what is known on the internet as a
"troll."
Trolls get their kicks from baiting other people using online discussion
forums.
"Bertie the Bunyip" is believed to be a commercial pilot living in the
United States.
He claims to have been similarly hounding newsgroups in the United
States for three years, despite complaints to the FBI and a libel action
against him.
After local users unwisely responded to his taunts, the Bunyip's replies
soon spread to the nz.comp and nz.politics newsgroups.
New Zealand politicians - including some ministers - are believed to use
the politics group.
In the past few days, the American has paralysed the most popular of the
local forums, nz.general, which is read by up to 50,000 people.
Bunyip's antics have prompted some users to stop using the newsgroups.
Bunyip changes his identity characteristics every 30 or 40 posts, so it
is difficult to check him using e-mail or newsreader software blocked
senders' lists.
David Farrar, a newsgroup user and information technology adviser to
National Party leader Jenny Shipley, described the "flame" war as the
worst outbreak of its kind he had seen on New Zealand discussion groups.
Applying sanctions against Usenet users could be extremely difficult,
said Mr Farrar.
Bunyip has been using a Seattle-based newsgroup service called Altopia,
which has a liberal policy on what it will allow.
"One of the problems of newsgroups is that they are about as close to
anarchy as anything can get," he said.
>
"If you get a person going rogue, as this Bertie the Bunyip has, you
would normally complain to their internet service provider.
"Unless it is causing actual harm, they don't see it as their job to
police it."
Xtra systems support specialist Richard Stevenson said he could easily
filter the messages from Xtra's news server - one of several providing
Usenet feeds in New Zealand.
But he would not decide to do so himself.
Mr Stevenson said he had not yet had to remove individual posts but had
occasionally, at the request of the Department of Internal Affairs,
blocked newsgroups that were related to child pornography.
He was not concerned about Bunyip's rights to freedom of speech.
"He's got to get it into his skull that [news servers] are private
property."
Mr Farrar believed that if Bunyip persisted for more than a couple of
weeks, local internet service providers might agree to remove him from
New Zealand servers.
But it was more likely that Bunyip would disappear quite quickly if
ignored.
Bertie the Bunyip
>
Nope, mostly has to do with putting it on the correct end for prop
instalation, splaps boy.
Peter Stickney
"Emmanuel Gustin" <Emmanue...@skynet.be> writes:
> The "core" (that is an anachronism, I know) of a V-12 engine
> is by definition highly assymetric. The natural tendency
> and logical choice for any designer is to use the gearbox
> to restore some symmetry by bringing the thrust line closer
> to the center of mass and the geometric center of the engine.
But it isn't always the case. Look at the P-39, the P-63, and the
FM-1 Airacuda. (Cheating, I know, with those remote gearboxes)
The thrust centerline isn't anywhere near the prop centerline.
Gord Beaman
--cut--
>> complicated, and the ease of getting to the cylinder heads is
>> mitigated by the need to get in there more often, because of the
>> effects of having the engine oil getting into the heads. Radials are
>> bad enough, with only a few cylinder pointing down!
>
>Radials tended to be total loss oil systems, so there was no return problem.
>Using vacuum to return oil from inverted engines is not really a complicated
>problem, other than temperature.
>
>John
>
>
anyway. The Argus had four R-3350's (one of the biggest radial
types) with a 54 Imperial gallon oil tank for each engine, and
while it burned it's share of oil it certainly had scavenge pumps
which pumped the return oil through the coolers and back to the
tank.
Bertie the Bunyip
In fact, every radial I can think of had a fully recirc oil system, if
you leave out some very early anzanis. Dry rockers were common until
the late thirties, but crankcase oil was always recirculated.
Tarver Engineering
Only the old ones Gord. You have to remember it was Harley Davidson that
taught the Japanese to build small air cooled engines. (ie Riku)
CJ Adams
>
>Radials tended to be total loss oil systems, so there was no return
problem.
>Using vacuum to return oil from inverted engines is not really a
complicated
>problem, other than temperature.
>
Cheers
Craig Adams
Arte et Marte
Ron Miller
: > That's got to be it. It aligns the crankshaft centerline high on the axis
: > of the aircraft giving prop clearance. (And at the time ALL fighters were
: > tailwheel airplanes except for a few oddballs)
: >
: That would certainly be true of direct-drive engines, but these engines were
: geared, propeller shafts turned at about half the speed of the crankshaft.
: In upright V engines the propeller is above the crankshaft, in inverted V
: engines the propeller is below the crankshaft.
I guess it depends a lot on the type of gearbox one uses. If a planetary
system is used then the prop and engine crank could wind up nearly co-axial
with associated low frontal area. If external edge mesh on the gears then
the prop axis and crank axis would be displaced.
I'm thinking of the planetary gearboxes I've seen recently when I visited
an old B-17 wreck. I *think* the prop was gear reduced from engine rpm
by planetary gears though I could be mistaking those pieces for the
accessory drives (kinda hard to tell for sure when the engine has been
cracked open like an egg) .
Ron Miller
Guy Alcala
In the case of French and German V-12s the lack of symmetry was an
issue, because the barrel of a 20mm cannon had to pass through the prop
spinner centerline. It was fairly easy to arrange for it to pass
through the center of the reduction gear. I think the cannon breech was
mounted between the 'V', but it could be it was mounted aft of that for
cooling reasons.
Guy
Gord Beaman
Not mistaken at all Ron, the Wright Cyclone R-3350 uses this
planetary gear reduction scheme and it does indeed leave the prop
shaft directly aligned with the crankshaft. It also provides
another very convenient function. the Stator Gear which the
planetary gears get their reference from can be (and often are)
instrumented so as to measure the force applied to them. This
affords a very convenient point to measure the torque applied to
the propshaft by the engine.
Tarver Engineering
"CJ Adams" <blue...@multiboard.com> wrote in message
news:OaDe7.11017$Z2.1...@nnrp1.uunet.ca...
>
> >
> >Radials tended to be total loss oil systems, so there was no return
> problem.
> >Using vacuum to return oil from inverted engines is not really a
> complicated
> >problem, other than temperature.
> >
> Ink Amendment, perhaps? Delete radial, insert rotary?
There was little reason to recover the oil to the heads. Still better than
the vegitable oil French motors. :)
Peter Stickney
gbe...@islandtelecom.com (Gord Beaman) writes:
> "Tarver Engineering" <jta...@sierratel.com> wrote:
> --cut--
>>
>>"Peter Stickney" <p-sti...@worldnet.att.net> wrote in message
>>>
>>> I'm not totally convinced of that. The lubrication system's more
>>> complicated, and the ease of getting to the cylinder heads is
>>> mitigated by the need to get in there more often, because of the
>>> effects of having the engine oil getting into the heads. Radials are
>>> bad enough, with only a few cylinder pointing down!
>>
>>Radials tended to be total loss oil systems, so there was no return problem.
>>Using vacuum to return oil from inverted engines is not really a complicated
>>problem, other than temperature.
> God no John, they certainly aren't, none that I know about
> anyway. The Argus had four R-3350's (one of the biggest radial
> types) with a 54 Imperial gallon oil tank for each engine, and
> while it burned it's share of oil it certainly had scavenge pumps
> which pumped the return oil through the coolers and back to the
> tank.
The R975 in the Sherman I had was certainly a circulating oil system,
and not total loss. Nor was the R670 in the M3 Light Tank.
(These basically were the Wright Whirlwind with a cooling fan added)
Nor were any of the R1820s/R1830s/R2800s I've played with.
Although Wrights sure do tend to throw their share around - some R3350
equipped airplanes were limited by oil capacity, rather than fuel.
There was a long-range kit for the AD/A-1 Skyraider that included an
extra oil tank.
The only use of a total loss oil system in practice that I know of was
the J65 (Wright re-bodge of the AS Sapphire). You could always tell
an early A-4 by the black strak down the side.
Bertie the Bunyip
>
>>
>>Radials tended to be total loss oil systems, so there was no return
>problem.
>>Using vacuum to return oil from inverted engines is not really a
>complicated
>>problem, other than temperature.
>>
>Ink Amendment, perhaps? Delete radial, insert rotary?
>
Nope, keep reading, he's talking radial.
Bertie the Bunyip
>r...@fc.hp.com (Ron Miller) wrote:
Actually, the only radial I can think of where the shafts are not in
line with each other are the little Pobjoys the Brits built in the
twenties and thirties.
Bertie the Bunyip
>
>"CJ Adams" <blue...@multiboard.com> wrote in message
>news:OaDe7.11017$Z2.1...@nnrp1.uunet.ca...
>>
>> >
>> >Radials tended to be total loss oil systems, so there was no return
>> problem.
>> >Using vacuum to return oil from inverted engines is not really a
>> complicated
>> >problem, other than temperature.
>> >
>> Ink Amendment, perhaps? Delete radial, insert rotary?
>
>There was little reason to recover the oil to the heads. Still better than
>the vegitable oil French motors. :)
They didn't pump oil to the heads in those rotaries, idiot.
Bertie the Bunyip
Uh, don't think so. Also the R670 in the M£ was a Continental AFAIK,
not a Wright.
Gord Beaman
--cut--
>Although Wrights sure do tend to throw their share around - some R3350
>equipped airplanes were limited by oil capacity, rather than fuel.
>There was a long-range kit for the AD/A-1 Skyraider that included an
>extra oil tank.
>
I've heard that same statement before but I don't know what kind
of a/c that was. In the Argus we flew about as long a patrol as
any a/c that I know of and unless we had a huge oil leakage
problem then we were never limited by lack of oil.
Our typical everyday run of the mill patrol was 18 hours with
many of those extended to 22 - 24 hours and although I flew them
for more than 8 years I don't recall ever running even 'low' on
oil. I've certainly had to cage one now and then due to an
excessive oil leak but that was more for fire avoidance than
anything.
Hell, each engine's oil tank held 54 Imperial gallons, you'd
need some kind of a wild consumption figure to go through that
amount in say 30 hours...and by then you're beginning to look
lovingly at just about any accessible airport with a fuel bowser
and a bed!. :)
Michael Williamson
> > The "core" (that is an anachronism, I know) of a V-12 engine
> > is by definition highly assymetric. The natural tendency
> > and logical choice for any designer is to use the gearbox
> > to restore some symmetry by bringing the thrust line closer
> > to the center of mass and the geometric center of the engine.
>
> But it isn't always the case. Look at the P-39, the P-63, and the
> FM-1 Airacuda. (Cheating, I know, with those remote gearboxes)
> The thrust centerline isn't anywhere near the prop centerline.
Presumably you mean that the prop centerline wasn't anywhere
near the crankshaft centerline. But the Allison's gearbox in the
P-39 wasn't all that much different than that installed on an Allison
in a P-38 (for the same rotation, anyways), but just mounted on
an extension shaft. All Allison V1710 engines after the C series
had a high thrust line.
Mike Williamson
Gord Beaman
>Gord Beaman wrote:
>
>> "Emmanuel Gustin" <Emmanue...@skynet.be> wrote:
--cut--
>
>> In any case, your suggestion that the gearbox should provide
>> symmetry to the thrust line seems a very small point to me. Sure,
>> if it's not detrimental in any way then ok, but the very
>> asymmetric design of the Allison T-56 and it's gearbox is proof
>> positive that the symmetry of these two units is somewhat
>> unimportant in a practical sense.
>
>In the case of French and German V-12s the lack of symmetry was an
>issue, because the barrel of a 20mm cannon had to pass through the prop
>spinner centerline.
Of course, the lack of symmetry in this case was important,
there's no practical way to get the gun to shoot through the prop
hub otherwise, but my statement was that the symmetry 'to the
thrustline' isn't very important, certainly not as important as
'hub accessability' or 'prop ground clearance issues' etc.
> It was fairly easy to arrange for it to pass
>through the center of the reduction gear. I think the cannon breech was
>mounted between the 'V', but it could be it was mounted aft of that for
>cooling reasons.
>
>Guy
>
And likely accessability too.
Emmanuel Gustin
> In the case of French and German V-12s the lack of symmetry was an
> issue, because the barrel of a 20mm cannon had to pass through the prop
> spinner centerline. It was fairly easy to arrange for it to pass
> through the center of the reduction gear. I think the cannon breech was
> mounted between the 'V', but it could be it was mounted aft of that for
> cooling reasons.
On German engines, aft of it; the tube that ran through a
DB engine was only 70mm in diameter. You can see the cannon
mounting flange at the rear end of the engine on pictures.
On the French HS12Xc and HS12Yc engine a part of the breech
was between the cylinder blocks. The Hispano cannon were
very long and slim designs.
As the ammunition feed had to be behind the engine, it was
impossible to mount the entire cannon in the V.
Emmanuel Gustin
Peter Stickney
I can't say without measuring some good cutaway drawings, but my
impression is that the 'Cobra's' thrust line is higher in relation to
the engine than is the case with Allisons that don't use the extension
shafts. The engine in he P-39 and P-63 was mounted quite low in the
airframe (The drive shaft had to pass below the cockpit) and the
difference between the engine's shaft line and the propeller shaft
line was made up by the gearbox.
Maury Markowitz
news:3b78ff41$0$241$4dbe...@businessnews.de.uu.net...
> I'm trying to find out *why* the inverted-V engines were so popular in
WWII
> aircraft, (specifically German). Can someone tell me what
> advantages/disadvantages the inverted-V had as compared to normal V
engines?
I believe the main advantage was that they placed most of the bulk lower
on the airframe which gave the planes better visibility - although they
threw that away on the 109 anyway.
Technical reasons include better heat balance. The cylinder head is the
hottest part of the engine, so putting it at the bottom means the heat rises
into the otherwise cooler regions. The result is less heat stress over the
whole engine. Also oil flow is theoretically better due to gravity feed.
Maury
Maury Markowitz
news:9lb9ct$99g$1...@suaar1aa.prod.compuserve.com...
> The Germans were building inverted Vee engines
> in the 20's and had no need to copy anyones designs
> since their engines were if anything more advanced
In comparison with contemportary engines from England or the US they
simply didn't stack up. They were much larger for a similar rating, with the
associated increase in fuel consumption. For instance the Merlin had roughly
the same power rating as the 601 when they first met in combat, yet the
Merlin was 27 litres to the 601's 34 (1325). By 1942 the same Merlin was
pumping out 1600hp, while the Germans had to move to the even larger 36
litre 605 (1655). Weight tended to me more fair however, with both engine
series having roughly the same weight for any given HP class.
Likewise the radial didn't do so well. Their earlier models like the
Fafnir and such were rather poor performers, and the BMW 139 on the road to
the 801 was a failure. The 801 was a development of the Pratt and Whitney
basic designs, and when the 801 finally did mature it never reached the same
levels of performance as it's US counterparts. Compare it with the Double
Wasp and there's really no comparison. Nor did they perform as well at
altitude.
Then you have to consider the endless stream of what appear to be really
bad ideas on how to improve altitude performance. Also note the total
failure of all higher power engines like the 222, whereas the British
engines, while certainly problematic, matured into fine 2500HP class
installations.
Maury
Keith Willshaw
"Maury Markowitz" <maury_m...@hotmail.com> wrote in message
news:zm%e7.42841$P87.3...@news20.bellglobal.com...
> "Keith Willshaw" <keith_w...@compuserve.com> wrote in message
> news:9lb9ct$99g$1...@suaar1aa.prod.compuserve.com...
> > The Germans were building inverted Vee engines
> > in the 20's and had no need to copy anyones designs
> > since their engines were if anything more advanced
>
> In comparison with contemportary engines from England or the US they
> simply didn't stack up. They were much larger for a similar rating, with
the
> associated increase in fuel consumption. For instance the Merlin had
roughly
> the same power rating as the 601 when they first met in combat, yet the
> Merlin was 27 litres to the 601's 34 (1325). By 1942 the same Merlin was
> pumping out 1600hp, while the Germans had to move to the even larger 36
> litre 605 (1655). Weight tended to me more fair however, with both engine
> series having roughly the same weight for any given HP class.
>
Yes but how much of this was due to the fuel that was
available. The Germans simply didnt have access
to the very high octane fuels available to the
Western Allies
Keith
Steven P. McNicoll
>
> I certainly bloody well DID review it sonny...
>
But you didn't engage your brain before doing so, old-timer.
>
> it starts off with
> someone asking why inverted V engines versus upright V engines...
>
> -Someone suggests 'maybe gravity?'...
>
> -Someone shoots that down and counter suggested, maybe ease of
> maintenance?...
>
> -Someone suggested maybe better visibility?...
>
> -Someone else agreed with that...(me too btw)...
>
> -YOU mentioned gearboxes...seeming to suggest that gearboxes
> would somehow defeat the visibility advantage of the invert.
>
That's not correct. JDupre5762 suggested the Germans used inverted Vs
because "it can be easier to align the thrust line of the engine with the
center of the airframe". Ron Miller agreed, adding "It aligns the
crankshaft centerline high on the axis of the aircraft giving prop
clearance." I said nothing at all about why the Germans used inverted Vs, I
just pointed out that having the crankshaft high on the engine did nothing
for propeller clearance, as the reduction gearing brought the propeller
shaft back down.
Look at the Messerschmitt Bf 109 as an example, the Bf 109 V1 made it's
first flight with a Rolls Royce Kestrel V, a geared upright V, because the
planned Jumo 210A, a geared inverted V, was not yet ready. The second
prototype, the Bf 109 V2, had the Jumo installed but it's thrust line was
the same as the Bf 109 V2. If anything, the inverted V installations tended
to have a lower thrust line than did the upright Vs, due to the reduction
gearing. Compare the Bf 109G to the Hispano HA1112.
>
> -I then mentioned that gearboxes could be mounted upright or
> inverted. (therefore shooting your theory down)
>
I presented no theory, your message had nothing to do with mine or with the
subject of this thread. I simply pointed out that the reduction of the
German inverted Vs moved the thrust line down, shooting down the theory that
they used the inverted V for greater propeller clearance.
>
> -You then came out with the gem that "We're discussing recips,
> here, not turbines".
>
> -I asked why the ENGINE TYPE matters....
>
The engine type matters because we're discussing a specific engine type, the
inverted V.
>
> -YOU couldn't answer that so reverted to insults...etc...
>
The answer was obvious, had you reviewed the thread, actually reading
instead of just looking at the words.
>
> That about sum it up?...(careful now, we're out in public here!)
> :)
>
Now it does.
Steven P. McNicoll
"Cub Driver" <lo...@my.sig.file> wrote in message
news:e1jknt8m0m80uo338...@4ax.com...
>
> Didn't the first 109 to fly have a British engine in it?
>
Yes, a Rolls Royce Kestrel V.
Steven P. McNicoll
>
> Problem?...none that I know of Emmanuel. We were just discussing
> inverting the engine (likely for visibility concerns) and someone
> mentioned gearboxes offsetting the propeller and that being a
> disadvantage, I then pointed out that the gearbox could be
> arranged as it is on some turboprops. This seemed to upset
> someone.
>
No, nobody mentioned gearboxes offsetting the propeller as being a
disadvantage, I simply pointed out that the gearbox lowered the thrust line
on an inverted V, negating any advantage of a higher thrust line otherwise
obtained by inverting the engine.
Steven P. McNicoll
>
> No, not really. It was a style thing, I'd say. Fashions exist in
> aircraft design, too. On a "visit your local airport" level,
> there wasn't any particular reason for Cessna to switch to those swept
> vertical stabilizers in the late '50s/early '60s, or for Piper to
> start putting T-tails on all their singles. (Warrior, etc.)
>
While Piper was on a T-tail binge for a while, the Warrior never had one.
Gord Beaman
--cut--
> I said nothing at all about why the Germans used inverted Vs, I
>just pointed out that having the crankshaft high on the engine did nothing
>for propeller clearance, as the reduction gearing brought the propeller
>shaft back down.
>
Which shows what you know about reduction gearing doesn't it
Steven?. I'll give you a small hint here, gleaned over the many
years that incidentally make me an 'oldtimer' (which you find
detrimental somehow, but which, actually, lets me know more than
you apparently do about reduction gearing at least).
Now then, apparently you don't know that reduction gearing can
bring the propeller shaft DOWN, UP, SIDEWAYS or not MOVE it AT
ALL. And that's what the subject of this section of the fricking
post was about wasn't it?.
You made the ERROR of saying exactly what you just repeated above
and I merely pointed out your error, not just by making a
statement alone but by giving examples (C-130, P-3 etc) THEN you
made another ERROR by complaining about TURBINE engines. For the
purposes of this part of the thread the engine type is
immaterial, it's the gearbox that's the subject. Get a grip
sonny. Try to stay focussed like us oldtimers can. If you need
lessons let me know, my rates are quite reasonable.
Gord Beaman
Michael Williamson
Peter Stickney wrote:
>
> I can't say without measuring some good cutaway drawings, but my
> impression is that the 'Cobra's' thrust line is higher in relation to
> the engine than is the case with Allisons that don't use the extension
> shafts. The engine in he P-39 and P-63 was mounted quite low in the
> airframe (The drive shaft had to pass below the cockpit) and the
> difference between the engine's shaft line and the propeller shaft
> line was made up by the gearbox.
Looking at a photo and the description in _Allied Aircraft Piston
Engines of World War II_, it seems that the gearbox is the same
on the E (P-39) and F (P-38 et al) series engines, except that it
is remotely located in the P-39, with an extension shaft. There
appears to be no difference in the amount of offset between the
input from the engine itself and the propellor shaft.
Mike
Steven P. McNicoll
> "Steven P. McNicoll" <ronca...@writeme.com> wrote:
> --cut--
> >
> > I said nothing at all about why the Germans used inverted Vs, I
> > just pointed out that having the crankshaft high on the engine did
> > nothing for propeller clearance, as the reduction gearing brought
> > the propeller shaft back down.
> >
>
> Which shows what you know about reduction gearing doesn't it
> Steven?
>
As it was applied to inverted V engines in German WWII aircraft, yes.
>
> I'll give you a small hint here, gleaned over the many
> years that incidentally make me an 'oldtimer' (which you find
> detrimental somehow, but which, actually, lets me know more than
> you apparently do about reduction gearing at least).
>
> Now then, apparently you don't know that reduction gearing can
> bring the propeller shaft DOWN, UP, SIDEWAYS or not MOVE it AT
> ALL. And that's what the subject of this section of the fricking
> post was about wasn't it?.
>
Could you tap that vast storehouse of old-timer knowledge and tell me what
German inverted V engine powered aircraft of WWII used reduction gearing to
bring the propeller shaft up, which moved it sideways, and which kept it in
the same position?
>
> You made the ERROR of saying exactly what you just repeated above
> and I merely pointed out your error, not just by making a
> statement alone but by giving examples (C-130, P-3 etc) THEN you
> made another ERROR by complaining about TURBINE engines. For the
> purposes of this part of the thread the engine type is
> immaterial, it's the gearbox that's the subject. Get a grip
> sonny. Try to stay focussed like us oldtimers can. If you need
> lessons let me know, my rates are quite reasonable.
>
Well, since the question in the subject line specifies German inverted V
engines of WWII it seems to me the engine type DOES matter.
Orval Fairbairn
"Steven P. McNicoll" <ronca...@writeme.com> wrote:
> "Gord Beaman" <gbe...@islandtelecom.com> wrote in message
> news:3b7d2616...@news1.islandtelecom.com...
> > "Steven P. McNicoll" <ronca...@writeme.com> wrote:
> > --cut--
> > >
> > > I said nothing at all about why the Germans used inverted Vs, I
> > > just pointed out that having the crankshaft high on the engine did
> > > nothing for propeller clearance, as the reduction gearing brought
> > > the propeller shaft back down.
> > >
> >
> > Which shows what you know about reduction gearing doesn't it
> > Steven?
> >
>
> As it was applied to inverted V engines in German WWII aircraft, yes.
>
The story I heard is that, at one of the major aviation expos in the
1930s, the Daimler Benz people were talking to the Rolls-Royce people
about future trends in aero engines. The RR guys, as a joke, said that
they saw the inverted vee as the engine of the future.
The DB guys ate it up and started development of the DB 600-series
engines.
--
Remove _'s from email address to talk to me.
Keith Willshaw
"Orval Fairbairn" <o_r_fairbairn@earth_link.net> wrote in message
news:o_r_fairbairn-387...@70-3-168-216.area5.spcsdns.net...
Its a nice story but almost certainly false. There was a history of German
inverted engines going back to at least the Argus AS-8 of 1928.
Keith
Dan
I bet it's a myth, but it's still funny. It reminds me of the one
where the Nazis built a fake aerodrome complete with wood airplanes. The
British observed with great interest while construction progressed. When
the project was complete the Brits flew over and dropped a wooden bomb.
Dan, U.S. Air Force, retired
Daryl Hunt
"Dan" <B2...@aol.com> wrote in message news:tvPNj.201$1M1...@newsfe23.lga...
One of the oldest stories is that RR was playing around with an inverted
Merlin when the Germans paid them a visit. It looked like a great idea on
paper. But RR never went into production of that Inverted Engine since it
only looked good on paper. The story goes that the Germans went back home
and went at it in ernest to prevent the British from having a leg up on
them.
** Posted from http://www.teranews.com **
Keith Willshaw
"Daryl Hunt" <dh...@nospami70west.com> wrote in message
news:cb310$4807cdb3$21...@news.teranews.com...
>
> One of the oldest stories is that RR was playing around with an inverted
> Merlin when the Germans paid them a visit. It looked like a great idea on
> paper. But RR never went into production of that Inverted Engine since it
> only looked good on paper. The story goes that the Germans went back home
> and went at it in ernest to prevent the British from having a leg up on
> them.
That would be a neat trick given that the DB-600 was in existence 2 years
before the first Merlin ran.
Keith
Andrew Robert Breen
Perhaps the original story involved an inverted Kestrel? Or an inverted
Buzzard? That, somehow, sounds more plausible as it would put it in the
era when RR were fiddling about with oddities like the Goshawk.
--
Andy Breen ~ Not speaking on behalf of the University of Wales, Aberystwyth
Feng Shui: an ancient oriental art for extracting
money from the gullible (Martin Sinclair)
a425couple
> "Orval Fairbairn" <o_r_fairbairn@earth_link.net> wrote> >> "Gord Beaman" <gbe...@islandtelecom.com> wrote ...
> >> > "Steven P. McNicoll" <ronca...@writeme.com> wrote:
> >> > > I said nothing at all about why the Germans used inverted Vs,
> Its a nice story but almost certainly false. There was a history of German
> inverted engines going back to at least the Argus AS-8 of 1928.
> Keith
What are the advantages of "inverted engines"?
(I can think of some disadvantages, that could all be
overcome ((with work and effort)), so if they did so,
they must have seen some advantages??)
Keith Willshaw
"Andrew Robert Breen" <a...@aber.ac.uk> wrote in message
news:vg2md5x...@news.aber.ac.uk...
> In article <fu9g5c$rdm$1$8300...@news.demon.co.uk>,
> Keith Willshaw <keith...@demon.co.uk> wrote:
>>
>>"Daryl Hunt" <dh...@nospami70west.com> wrote in message
>>news:cb310$4807cdb3$21...@news.teranews.com...
>>
>>>
>>> One of the oldest stories is that RR was playing around with an inverted
>>> Merlin when the Germans paid them a visit. It looked like a great idea
>>> on
>>> paper. But RR never went into production of that Inverted Engine since
>>> it
>>> only looked good on paper. The story goes that the Germans went back
>>> home
>>> and went at it in ernest to prevent the British from having a leg up on
>>> them.
>>
>>That would be a neat trick given that the DB-600 was in existence 2 years
>>before the first Merlin ran.
>
> Perhaps the original story involved an inverted Kestrel? Or an inverted
> Buzzard? That, somehow, sounds more plausible as it would put it in the
> era when RR were fiddling about with oddities like the Goshawk.
>
More likely they saw the Argus AS10 , a 1928 inverted vee used by
the Arado 66, FW 56 , FW 58 and Fiesler Storch then there
are the inverted DH and Blackburn engines like the Gypsy Queen and
Cirrus, not vees of course.
Keith
Keith Willshaw
"a425couple" <a425c...@hotmail.com> wrote in message
news:tridndX-cvJeXJXV...@comcast.com...
> "Keith Willshaw" <keith...@demon.co.uk> wrote ...
>> "Orval Fairbairn" <o_r_fairbairn@earth_link.net> wrote
>> > "Steven P. McNicoll" <ronca...@writeme.com> wrote:
>> >> "Gord Beaman" <gbe...@islandtelecom.com> wrote ...
>> >> > "Steven P. McNicoll" <ronca...@writeme.com> wrote:
>> >> > > I said nothing at all about why the Germans used inverted Vs,
>> >> -- inverted V engines in German WWII aircraft, yes.
>
>> Its a nice story but almost certainly false. There was a history of
>> German
>> inverted engines going back to at least the Argus AS-8 of 1928.
>> Keith
>
> What are the advantages of "inverted engines"?
>
As others have posted it potentially allows the highest part
of the engine to be below the pilots line of sight and
it may improve heat flow to have the hottest part of the
engine at the bottom.
Dry sump lubrication means under high and negative gees
you dont have to worry about oil swirling around the crankshaft
or getting places you dont want it
Keith
dumbstruck
> "a425couple" <a425cou...@hotmail.com> wrote in message
> > What are the advantages of "inverted engines"?
>
> As others have posted it potentially allows the highest part
> of the engine to be below the pilots line of sight and
A Vietnam era dogfight was covered on TV where the Phantom pilot
pointed out he had to waggle his tail to keep the Mig in sight. Since
he was leading the Mig in gunsights, and they were both in a banked
turn, vision to the side and down was key (something an i-v would
enhance).
a425couple
> "Keith Willshaw" <keithnos...@demon.co.uk> wrote:
> > "a425couple" <a425cou...@hotmail.com> wrote in message
> > > What are the advantages of "inverted engines"?
> >
> vision to the side and down
Thank you both
(for whatever reason ((sure it my fault))
I'm not seeing much earlier postings re: this)
Yes, I'm familiar with dry sump.
And understand that the concerns in auto
(center of gravity, access to some areas for service
((esp. carbs, electrical, plugs)) )
are not same issues in airplanes.
Again, Thanks.
Keith Willshaw
Sure although the DB600 series engines used fuel injection
rather than carburettors.
There are some nice photos and diagrams of the DB-605 at
http://www.aviation-history.com/engines/db605.htm
Keith
Dan_Thom...@yahoo.com
> "a425couple" <a425cou...@hotmail.com> wrote in message
>
> news:tridndX-cvJeXJXV...@comcast.com...
>
> > "Keith Willshaw" <keithnos...@demon.co.uk> wrote ...
> >> "Orval Fairbairn" <o_r_fairbairn@earth_link.net> wrote
> >> > "Steven P. McNicoll" <roncach...@writeme.com> wrote:
> >> >> "Gord Beaman" <gbea...@islandtelecom.com> wrote ...
> >> >> > "Steven P. McNicoll" <roncach...@writeme.com> wrote:
> >> >> > > I said nothing at all about why the Germans used inverted Vs,
> >> >> -- inverted V engines in German WWII aircraft, yes.
>
> >> Its a nice story but almost certainly false. There was a history of
> >> German
> >> inverted engines going back to at least the Argus AS-8 of 1928.
> >> Keith
>
> > What are the advantages of "inverted engines"?
>
> As others have posted it potentially allows the highest part
> of the engine to be below the pilots line of sight and
> it may improve heat flow to have the hottest part of the
> engine at the bottom.
>
> Dry sump lubrication means under high and negative gees
> you dont have to worry about oil swirling around the crankshaft
> or getting places you dont want it
>
> Keith
Inverted engines allow them to be direct-drive (which means
strong and simple) and still keep thrust line high while improving
visibility over the nose. And that's all there is to it! Any other
ideas are purely speculation. Any engine can be made dry-sump,
including upright inlines or vees or opposed engines. Many are, to
make them aerobatic. Gearing an inline or vee using spur gears (or
belts or chains) allows the engine to be turned upright and still keep
the prop up out of the dirt yet without any machinery up in the
pilot's line of sight. And gearing it allows it to turn faster and
generate more hp, since horsepower is equal to Torque (in ft-lb) times
RPM times 6.28 divided by 33,000. Increasing RPM usually costs some
torque, but the net output is still much higher.
Inverted engines have plenty of drawbacks.
1. They MUST be dry sump, and the cylinders must extend into the case
an inch or so to minimize the draining oil running into them (and that
extra inch makes the engine a little taller and heavier). And powered
scavenging of the oil is usually necessary.
2. Oil tends to drip into the cylinders off everything above them
after shutdown, and that oil seeps past the rings and fouls the
sparkplugs so they don't fire and if there's enough oil in there, it
will cause hydraulic lock on compression when the engine is started
and the con rod will get bent or the cylinder or piston might get
busted. Radials are really bad for that.
3. Oiling the rockers becomes a first-class hassle, with more
scavenging needed from the rocker covers, or just letting it run
overboard like it did in my Gipsy Major. Wasteful and messy and
something of a fire hazard. Even at that, the Gipsy had three oil
pumps: one for the pressure and two scavenge pumps, one for each end
of the crankcase. It was a four-cylinder engine that needed a 12-
quart oil tank to allow for that and the fact that it used so much
oil, with gravity working against the oil rings.
But I like the look of the inline. I miss that dumb Gipsy (it
was in an Auster AOP VI). I like Wittman's conversion of the early
'60s Buick aluminum V-8 to an inverted affair, but I wonder if he
installed longer sleeves in it to control the drainback. It was still
heavy for its power, because it was direct-drive.
Dan
Robert Sveinson
<Dan_Thom...@yahoo.com> wrote in message
news:0a9faaea-e580-4ab5...@n1g2000prb.googlegroups.com...
> Inverted engines allow them to be direct-drive (which means
> strong and simple) and still keep thrust line high while improving
> visibility over the nose. And that's all there is to it!
The Daimler Benz engines used in the Bf/Me109 aircraft
had a gear box on the front which allowed the prop centre
to be between the banks of the V12 engine. A 20mm cannon
was sometimes fitted to fire through the propellor hub,
which would not be possible if the prop was connected directly
to the crankshaft.
Keith Willshaw
>
> Inverted engines allow them to be direct-drive (which means
> strong and simple) and still keep thrust line high while improving
> visibility over the nose. And that's all there is to it!
Trouble is the DB-600 series werent direct drive
http://www.pilotfriend.com/aero_engines/aero_db605.htm
DOH !
Keith
Dan_Thom...@yahoo.com
> <Dan_Thomas_nos...@yahoo.com> wrote in message
I couldn't find any proof, but I'd bet that the DB series
were a development of an earlier direct-drive inverted engine, where
all the systems were there for oil scavenging and to recast the case
with scavenge ports relocated to the bottom and drains between the
rockers and sump, and redesigning the whole mounting arrangement, made
less sense than just leaving it inverted. I also thing that's why the
gearing is rather small: to limit the drop in thrustline.
Dan
Robert Sveinson
<Dan_Thom...@yahoo.com> wrote in message
news:58301cda-90c3-4c3c...@b5g2000pri.googlegroups.com...
>> Trouble is the DB-600 series werent direct drive
>>
>> http://www.pilotfriend.com/aero_engines/aero_db605.htm
>
> I couldn't find any proof, but I'd bet that the DB series
> were a development of an earlier direct-drive inverted engine,
The DB series started with DB-600.
http://www.adlertag.de/motoreneng.htm
To increase the power of the "Messerschmidt", the constructors were
searching for a more powerful engine and found it with the "Daimler-Benz DB
600". This engine was developed in 1932. It was a liquid cooled and in
version "DB 600 A" it was produced, with a maximum power of 800 hp. Like
"Jumo 210" the "DB 600" was a 12 zylinder engine with charger but no
injection system.
This engine only saw duty in the small "Bf 109 D" series, because it soon
was replaced by "DB 601".
In 1934, the "DB 600" was reconstructed and was fittet with a fuel injection
system. **Apart from this change and a changed airscrew transmission, the
"DB 601" didn´t differ much from his predicessor.**
Like the "Jumo 210" and the "DB 600", the "DB 601" was a liquid cooled 12
cylinder engine. Again the cylinders were arranged in a "hanging V".
The different Versions of the "DB 601" saw duty in all "Bf 109 E", "T", "F"
and the preproduction of "Bf 109 G" the "G-0".
The "DB 601" gave the "Bf 109" (in it´s version A and N) 1175 hp, later, the
DB 601 E had 1350 hp.
For a short time it was even possible to increase the power of the engine by
giving him the so called "Schuss" (shoot). In this process, a mixture of
water and methanol was injectetd in the cooling, what increased the power
for about 5 minutes.
got2go...@gmail.com
> In article <9lb9ct$99g$1...@suaar1aa.prod.compuserve.com>,
> "Keith Willshaw" <keith_w...@compuserve.com> writes:
> >
> > "Martin Winchester" <zeb...@giberish.hotmail.com> wrote in message
> > news:9lb62b$ah0$1...@oceanus.connect.org.uk...
> >> Ok.... this story might be aprocafull... i'm not sure but here goes...
> >>
> >> The way I understood it was that a delegation from germany around 1935/36
> >> visited Rolls Royce, and saw an early Merlin.
> >> The engine was inverted while being worked on. Nobody bothered to tell the
> >> Germans this and they left under the impression that RR were working on an
> >> inverted V12. This then spured them into developing inverted engines...
> > and
> >> the rest is history...
> >>
> >> This story may be an urban myth... so don't shoot me down please......!
> > Its hogwash
>
> I Concur. There are enough other characteristics about the Merlin, or
> any other engine, that would tell any competent observer that it's
> just a regular engine upside-down. However, Rolls did do some studies
> on inverted-vee engines.
>
> >
> > The Germans were building inverted Vee engines
> > in the 20's and had no need to copy anyones designs
> > since their engines were if anything more advanced
>
> On that I don't agree. The German inline engines tended to be huge
> honkin' pieces of metal, with rather poor Specific Power (HP/swept
> volume) While they had some neat ideas, lie the oil-driven variable
> speed superchargers of the DB601 and DB605, they also had a lot of
> problems gettig it to work right, especially in the field.
> Daimler-Benz and Messerschmitt went 'round and 'round on that for
> years. (It seems that the supercharger drives were failing due to
> cavitation if the oil. Messerschmitt kept telling Daimler that it was
> an oil pump probkem. Daimler kept insisting that the problem was
> Messerschmitt's design of the oil tanks.) They also didn't get the
> same supercharger efficiencies, which led to such expedients as
> Nitrous Oxide injection to improve the critical altitude of the
> engine. (That's the sort of thing you do when other options are no
> feasable.)
>
> The BMW 801 was a fantastic bit of machinery, though.
>
> >
> > For example their use of fuel injection gave the Luftwaffe
> > a considerable advantage in the early part of the BOB
>
> At a cost in other areas. It turned out that the best solutions were
> the Bendix-Stromberg or Chandler-Evans Pressure Carburetors, which
> injected fuel into the airstream upstream of teh engine-stage
> supercharger, giving a lot of charge cooling, and even mixture
> distribution via the supercharger itself, or the NACA Injection
> Impeller, ehich used the supercharger impeller to distribute fuel,
> with the same advantages.
>
> The Germans weren't foolish or stupid, but I see their inlines as
> suffering from "Creeping Featuritus", as their most distinguishing
> characteristic.
>
>
> --
> Pete Stickney
> A strong conviction that something must be done is the parent of many
> bad measures. -- Daniel Webster
Peter from what I have read the NOX injection system was just one more way to extend a design (the BF 109) to the extreme without having to go to a new engine and new aircraft design. At that time in the War Germany would have had major issues trying to launch yet another aircraft design and manufacturing effort. Also at that time, the Allies had mastered multi-stage superchargers that provided them with superior high altitude performance. Toward the end of the war, the 109 began having structural failures because the design limits had been reached for weight and stress like high G turns, also landings often overstressed the airframe, so larger engines were not an option.
a425couple
> On Tuesday, August 14, 2001 at 4:37:49 PM UTC-4, Peter Stickney wrote:
>> In article <9lb9ct$99g$1...@suaar1aa.prod.compuserve.com>,
>> "Keith Willshaw" <keith_w...@compuserve.com> writes:
>>>
>>> "Martin Winchester" <zeb...@giberish.hotmail.com> wrote in message
>>> news:9lb62b$ah0$1...@oceanus.connect.org.uk...
>>>> Ok.... this story might be aprocafull... i'm not sure but here goes...
>>>>
>>>> The way I understood it was that a delegation from germany around 1935/36
>>>> visited Rolls Royce, and saw an early Merlin.
>>>> The engine was inverted while being worked on. Nobody bothered to tell the
>>>> Germans this and they left under the impression that RR were working on an
>>>> inverted V12. This then spured them into developing inverted engines...
>>> and
>>>> the rest is history...
>>>>
>>>> This story may be an urban myth... so don't shoot me down please......!
>>> Its hogwash
>>
>> I Concur. There are enough other characteristics about the Merlin, or
>> any other engine, that would tell any competent observer that it's
>> just a regular engine upside-down. However, Rolls did do some studies
>> on inverted-vee engines.
>>>
>>> The Germans were building inverted Vee engines
Would someone please try explaining to me how they
solve the oiling issues in an "inverted Vee" engine?
In a normal V engine, or in a normal inline engine the
oil lubricates the rods and the crank, then by gravity
falls to the sump. (In a "wet sump" system it can sit there,
and in a "dry sump" system it is pumped to a separate
storage tank.) But if the engine is inverted, where
does the oil gather so it can be picked up?
And, while I'm asking a stupid question, how is the
oil scavenged for reuse from a rotary engine?
Keith Willshaw
>
> Would someone please try explaining to me how they
> solve the oiling issues in an "inverted Vee" engine?
>
> In a normal V engine, or in a normal inline engine the
> oil lubricates the rods and the crank, then by gravity
> falls to the sump. (In a "wet sump" system it can sit there,
> and in a "dry sump" system it is pumped to a separate
> storage tank.) But if the engine is inverted, where
> does the oil gather so it can be picked up?
>
oil tank. In its simplest form it just collects in oil galleries on the
lower part of the crankcase. Visibilty was considered a major advantage
as the widest part of the engine is at the bottom instead of blocking
the pilots view. A secondary advantage was that on the BF-109 was that
they were able to fit a cannon with the barrel in the vee that fired
through the propellor boss.
> And, while I'm asking a stupid question, how is the
> oil scavenged for reuse from a rotary engine?
WW1 Rotary engines as distinct from Radials had a total loss lubrication
system. With rotaries the crankshaft was bolted to the aircraft and the
engine complete with attached propellor rotated. Given that the most
common lubricant in WW1 aircraft was Castor Oil constation was not a
problem for pilots.
The later Wankel engines also used this technique to lubricate the seal
tips which is one reason they failed to meet modern emission standards.
Jim Wilkins
news:perp3j$lqc$1...@dont-email.me...
http://www.wwiiaircraftperformance.org/me109/DB-601A-Flight-7Nov40.pdf