Allison B-17

Saw a photo yesterday of a WWII B-17 test aircraft powered
with four Allison inline engines as opposed to the usual
Wright Cyclones.

Understand the modification added about 800 hp to the
aircraft.

Anyone know why the modification didn't go anywhere?
The usual suspects? Too much disruption to B-17
production? Engines needed by P-38, P-39, P-40?

Sorta "Lanc looking".


SMH

Cant remeber exactly but werent the allison engines unsuitable because they
were no good above a certain altitude!?
"Stephen Harding" wrote in message
...
Saw a photo yesterday of a WWII B-17 test aircraft powered
with four Allison inline engines as opposed to the usual
Wright Cyclones.

Understand the modification added about 800 hp to the
aircraft.

Anyone know why the modification didn't go anywhere?
The usual suspects? Too much disruption to B-17
production? Engines needed by P-38, P-39, P-40?

Sorta "Lanc looking".


SMH

"M. H. Greaves" wrote in message
...
Cant remeber exactly but werent the allison engines unsuitable because
they
were no good above a certain altitude!?

The P-38 had a ceiling of forty thousand feet with Allison inlines.

Brooks

"Stephen Harding" wrote in message
...
Saw a photo yesterday of a WWII B-17 test aircraft powered
with four Allison inline engines as opposed to the usual
Wright Cyclones.

Understand the modification added about 800 hp to the
aircraft.

Anyone know why the modification didn't go anywhere?
The usual suspects? Too much disruption to B-17
production? Engines needed by P-38, P-39, P-40?

Sorta "Lanc looking".


SMH

yep, but like i say, i cant remember offhand, and i think it was either the
P51 or the P40, that had that trouble; no doubt there was a good valiud
reason at the time.
Its a similar sort of thing to the B17 at Duxford, they dont use the turbo's
because it tears hell out of the engines; thats what i was told by a
mechanic who was working on one of the engines at the time. They were
changing an engine and needed a certain part which was still on the a/c at
the time and the chap gave me an impromptu guided tour around it, as well as
inside; real nice chap.
I s'pose they dont fly the B17 as much as it would normally be operated so
they dont need the turbos and because they dont carry any heavy ordnance
these days either, what with the war being over and all that. lol
But i wonder, they obviously choose what weather they fly, as the turbo was
used to guard against carb' icing conditions as well as many other uses such
as more power.
I have a very interesting video i bought at an airshow called flying the B17
and it goes into the induction system at great length, real interesting
stuff.
Wasnt there only one kind of allison engine i.e. the inline engine, or are
you talking about the one in the C130 hercules?!
"Kevin Brooks" wrote in message
...

"M. H. Greaves" wrote in message
...
Cant remeber exactly but werent the allison engines unsuitable because
they
were no good above a certain altitude!?

The P-38 had a ceiling of forty thousand feet with Allison inlines.

Brooks

"Stephen Harding" wrote in message
...
Saw a photo yesterday of a WWII B-17 test aircraft powered
with four Allison inline engines as opposed to the usual
Wright Cyclones.

Understand the modification added about 800 hp to the
aircraft.

Anyone know why the modification didn't go anywhere?
The usual suspects? Too much disruption to B-17
production? Engines needed by P-38, P-39, P-40?

Sorta "Lanc looking".


SMH

"M. H. Greaves" wrote in message
...

Wasnt there only one kind of allison engine i.e. the inline engine, or are
you talking about the one in the C130 hercules?!

Allison was the name of an engine manufacturer that made a
wide range of engines. IRC its now a subsidiary of RollsRoyce

Keith

Keith Willshaw wrote:

"M. H. Greaves" wrote in message
...

Wasnt there only one kind of allison engine i.e. the inline engine, or are
you talking about the one in the C130 hercules?!

Allison was the name of an engine manufacturer that made a
wide range of engines. IRC its now a subsidiary of RollsRoyce

There is an Allison transmission division of GM that still makes
[very good I understand] truck transmissions.

Is this a different Allison than the WWII engine maker?


SMH

In article ,
"M. H. Greaves" wrote:

I don't know why the turbo would "tear hell out of the engine" unless
you overboosted them...which you can do without using the turbo.

The B-17 I flew had the turbo's disconnected. By negating all the duct
work needed to feed air to the turbo we were still able to develop the
same amount of power for takeoff....so there was no loss of performance
by not using the turbo until you gained some altitude. High and hot we
sometimes were wishing the turbos were working. G I also flew a B-24
that had working turbos. We had to use the turbo's due to power loss
caused by the ductwork...and of course at higher altitudes they payed
off nicely also.

yep, but like i say, i cant remember offhand, and i think it was either the
P51 or the P40, that had that trouble; no doubt there was a good valiud
reason at the time.
Its a similar sort of thing to the B17 at Duxford, they dont use the turbo's
because it tears hell out of the engines; thats what i was told by a
mechanic who was working on one of the engines at the time. They were
changing an engine and needed a certain part which was still on the a/c at
the time and the chap gave me an impromptu guided tour around it, as well as
inside; real nice chap.
I s'pose they dont fly the B17 as much as it would normally be operated so
they dont need the turbos and because they dont carry any heavy ordnance
these days either, what with the war being over and all that. lol
But i wonder, they obviously choose what weather they fly, as the turbo was
used to guard against carb' icing conditions as well as many other uses such
as more power.
I have a very interesting video i bought at an airshow called flying the B17
and it goes into the induction system at great length, real interesting
stuff.
Wasnt there only one kind of allison engine i.e. the inline engine, or are
you talking about the one in the C130 hercules?!
"Kevin Brooks" wrote in message
...

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

Maybe then they dont fly at high altitudes from airshow to airshow thus dont
need it!? (i mean the Duxford boys).
"Dale" wrote in message
...
In article ,
"M. H. Greaves" wrote:

I don't know why the turbo would "tear hell out of the engine" unless
you overboosted them...which you can do without using the turbo.

The B-17 I flew had the turbo's disconnected. By negating all the duct
work needed to feed air to the turbo we were still able to develop the
same amount of power for takeoff....so there was no loss of performance
by not using the turbo until you gained some altitude. High and hot we
sometimes were wishing the turbos were working. G I also flew a B-24
that had working turbos. We had to use the turbo's due to power loss
caused by the ductwork...and of course at higher altitudes they payed
off nicely also.

yep, but like i say, i cant remember offhand, and i think it was either
the
P51 or the P40, that had that trouble; no doubt there was a good valiud
reason at the time.
Its a similar sort of thing to the B17 at Duxford, they dont use the
turbo's
because it tears hell out of the engines; thats what i was told by a
mechanic who was working on one of the engines at the time. They were
changing an engine and needed a certain part which was still on the a/c
at
the time and the chap gave me an impromptu guided tour around it, as
well as
inside; real nice chap.
I s'pose they dont fly the B17 as much as it would normally be operated
so
they dont need the turbos and because they dont carry any heavy ordnance
these days either, what with the war being over and all that. lol
But i wonder, they obviously choose what weather they fly, as the turbo
was
used to guard against carb' icing conditions as well as many other uses
such
as more power.
I have a very interesting video i bought at an airshow called flying the
B17
and it goes into the induction system at great length, real interesting
stuff.
Wasnt there only one kind of allison engine i.e. the inline engine, or
are
you talking about the one in the C130 hercules?!
"Kevin Brooks" wrote in message
...

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

"M. H. Greaves" wrote in message
...
Cant remeber exactly but werent the allison engines unsuitable because
they
were no good above a certain altitude!?

Depends on which Allison engines

When fitted with a turbo supercharger as in the P-38
they were fine, with a less capable blower setup
as used in the P-40 they were less good but then thats
tue of various marques or Merlin too.

Keith

Stephen Harding wrote:

: Anyone know why the modification didn't go anywhere?

The XB-38 was lost before much testing could be
done. It was slightly faster, but not enough
to make it worth the effort. And the V-1710
was of course much more vulnerable to combat
damage than a radial.

Later Boeing built an XB-39, which was a B-29
with four V-3420 engines, but this too was not
attractive enough to justify production.

Emmanuel Gustin