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Subaru: was Engines and props

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bransom

Subaru: was Engines and props

Post by bransom » Sat Feb 18, 2012 9:27 am

Ken,
Like any engine's max rated HP, that number is rarely reached in real life.
Do you know of any tricks in getting more HP that work on a 2.2 and not on a
2.5? All of the power enhancements I've read about seem to apply similarly
to the two engines, with equal believability or skepticism. Or, maybe you're
just saying an EJ25 isn't really going to deliver more power than a Lyc 0320?
-Ben

8/28/2004 6:28 AM, KLEHMAN@ALBEDO.NET wrote to REBEL-BUILDERS:
Ben

I would guess that it could be done but probably not without custom
exhaust and intake.

FWIW I consider the 2.5 TOPPED at 165 hp normally aspirated in stock
internal condition. The claim that the stock engine makes 165 because
the computer says 100% load is bogus. Fundamentally all the later oem
computer knows is rpm and manifold pressure so it reports 100% if those
parameters are met regardless of actual mass flow or power. Once you
change the exhaust or (especially) the intake that may or may not
correspond to 165 hp. The computer has no way of reading actual power.
Fuel flow is meaningless because the oxygen sensor is full scale rich
and ignored at aircraft power settings. Unlike the 2.2, the 2.5 is not
an easy engine to coax more power out of as the factory has done their
homework.

Ken


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Mike Davis

Subaru: was Engines and props

Post by Mike Davis » Sat Feb 18, 2012 9:27 am

Not sure how accurate the power ratings on these motors are, but there are
plenty of testimonials with real numbers flying behind them and the bottom
line is that the Eggenfellnor Subs fly the same airplane "slightly" better
than the O-320. Most are seeing a slightly better climb, and comparable
cruise speeds. The biggest difference is the smoothness and quietness of
the motors, and the fact that they are doing it on much less fuel. Sure
wish Jan made a 350-400 HP Sub for my Moose!

Mike

----- Original Message -----
From: <bransom@dcsol.com>
To: <rebel-builders@dcsol.com>
Sent: Sunday, August 29, 2004 9:04 AM
Subject: Re: Subaru: was Engines and props

Ken,
Like any engine's max rated HP, that number is rarely reached in real
life.
Do you know of any tricks in getting more HP that work on a 2.2 and not on
a
2.5? All of the power enhancements I've read about seem to apply
similarly
to the two engines, with equal believability or skepticism. Or, maybe
you're
just saying an EJ25 isn't really going to deliver more power than a Lyc
0320?
-Ben

8/28/2004 6:28 AM, KLEHMAN@ALBEDO.NET wrote to REBEL-BUILDERS:
Ben

I would guess that it could be done but probably not without custom
exhaust and intake.

FWIW I consider the 2.5 TOPPED at 165 hp normally aspirated in stock
internal condition. The claim that the stock engine makes 165 because
the computer says 100% load is bogus. Fundamentally all the later oem
computer knows is rpm and manifold pressure so it reports 100% if those
parameters are met regardless of actual mass flow or power. Once you
change the exhaust or (especially) the intake that may or may not
correspond to 165 hp. The computer has no way of reading actual power.
Fuel flow is meaningless because the oxygen sensor is full scale rich
and ignored at aircraft power settings. Unlike the 2.2, the 2.5 is not
an easy engine to coax more power out of as the factory has done their
homework.

Ken


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Ken

Subaru: was Engines and props

Post by Ken » Sat Feb 18, 2012 9:27 am

Hi Ben

Mostly I'm saying that just because the factory number is 165 hp is no
reason to believe that the commercial stock 2.5 conversions are in fact
achieving that. I have heard a lot of claims and technical obfuscation
though. I guess I got the impression you might be expecting to get even
more than 165 hp.

There are a few people that have worked with both engines and that I
respect that have said that the 2.5 does not respond near as much to
things like cam grinds as the 2.2. In one case the fellow talked about
the bore to stroke ratio as being a significant factor between the two
engines. I believe a cam grind, to extend the rpm that the torque peak
occurs at, is by far the biggest mod that you can really do as these
are not like the old EA81 where there are many things that each add a
bit of power. There are believable third party dyno numbers for the 2.2
that are consistent with the factory numbers stock and that show a 25 hp
increase to 160 hp with a cam grind. While I'd definately use a 2.5 if
doing it again, I would realistically not count on more than about 150
hp from the stock normally aspirated engine with modified intake and
exhaust. With expertise and dyno testing you could probably/assuredly do
better but I have seen no convincing evidence of that achievement so
far. Nor would I expect an extra 25 hp from cam grinds like in the 2.2.
By all accounts the 2.5 is an excellant 0-320 alternative but it is
already a highly tuned engine with little to be gained by mods from what
I understand.

OTOH if you are burning and carrying less fuel and perhaps have a lower
drag cooling system, it may be as good as having some extra power ;)

Ken

bransom@dcsol.com wrote:
Ken,
Like any engine's max rated HP, that number is rarely reached in real
life.
Do you know of any tricks in getting more HP that work on a 2.2 and
not on a
2.5? All of the power enhancements I've read about seem to apply
similarly
to the two engines, with equal believability or skepticism. Or, maybe
you're
just saying an EJ25 isn't really going to deliver more power than a
Lyc 0320?
-Ben

8/28/2004 6:28 AM, KLEHMAN@ALBEDO.NET wrote to REBEL-BUILDERS:

Ben

I would guess that it could be done but probably not without custom
exhaust and intake.

FWIW I consider the 2.5 TOPPED at 165 hp normally aspirated in stock
internal condition. The claim that the stock engine makes 165 because
the computer says 100% load is bogus. Fundamentally all the later oem
computer knows is rpm and manifold pressure so it reports 100% if those
parameters are met regardless of actual mass flow or power. Once you
change the exhaust or (especially) the intake that may or may not
correspond to 165 hp. The computer has no way of reading actual power.
Fuel flow is meaningless because the oxygen sensor is full scale rich
and ignored at aircraft power settings. Unlike the 2.2, the 2.5 is not
an easy engine to coax more power out of as the factory has done their
homework.

Ken





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Mike Davis

Subaru: was Engines and props

Post by Mike Davis » Sat Feb 18, 2012 9:27 am

I don't know the first thing about the mods that are made to the motors...
but the WRX 2.0 liter is 220 HP and on the World Rally circuit they are
getting up to 350 HP out of the same motor... so there are obviously things
that can be done. Just amazing that they can get that kind of power out of
those motors and they still prove to be some of the most reliable motors on
the circuit.

Mike

----- Original Message -----
From: "Ken" <klehman@albedo.net>
To: <rebel-builders@dcsol.com>
Sent: Sunday, August 29, 2004 6:30 PM
Subject: Re: Subaru: was Engines and props

Hi Ben

Mostly I'm saying that just because the factory number is 165 hp is no
reason to believe that the commercial stock 2.5 conversions are in fact
achieving that. I have heard a lot of claims and technical obfuscation
though. I guess I got the impression you might be expecting to get even
more than 165 hp.

There are a few people that have worked with both engines and that I
respect that have said that the 2.5 does not respond near as much to
things like cam grinds as the 2.2. In one case the fellow talked about
the bore to stroke ratio as being a significant factor between the two
engines. I believe a cam grind, to extend the rpm that the torque peak
occurs at, is by far the biggest mod that you can really do as these
are not like the old EA81 where there are many things that each add a
bit of power. There are believable third party dyno numbers for the 2.2
that are consistent with the factory numbers stock and that show a 25 hp
increase to 160 hp with a cam grind. While I'd definately use a 2.5 if
doing it again, I would realistically not count on more than about 150
hp from the stock normally aspirated engine with modified intake and
exhaust. With expertise and dyno testing you could probably/assuredly do
better but I have seen no convincing evidence of that achievement so
far. Nor would I expect an extra 25 hp from cam grinds like in the 2.2.
By all accounts the 2.5 is an excellant 0-320 alternative but it is
already a highly tuned engine with little to be gained by mods from what
I understand.

OTOH if you are burning and carrying less fuel and perhaps have a lower
drag cooling system, it may be as good as having some extra power ;)

Ken

bransom@dcsol.com wrote:
Ken,
Like any engine's max rated HP, that number is rarely reached in real
life.
Do you know of any tricks in getting more HP that work on a 2.2 and
not on a
2.5? All of the power enhancements I've read about seem to apply
similarly
to the two engines, with equal believability or skepticism. Or, maybe
you're
just saying an EJ25 isn't really going to deliver more power than a
Lyc 0320?
-Ben

8/28/2004 6:28 AM, KLEHMAN@ALBEDO.NET wrote to REBEL-BUILDERS:

Ben

I would guess that it could be done but probably not without custom
exhaust and intake.

FWIW I consider the 2.5 TOPPED at 165 hp normally aspirated in stock
internal condition. The claim that the stock engine makes 165 because
the computer says 100% load is bogus. Fundamentally all the later oem
computer knows is rpm and manifold pressure so it reports 100% if those
parameters are met regardless of actual mass flow or power. Once you
change the exhaust or (especially) the intake that may or may not
correspond to 165 hp. The computer has no way of reading actual power.
Fuel flow is meaningless because the oxygen sensor is full scale rich
and ignored at aircraft power settings. Unlike the 2.2, the 2.5 is not
an easy engine to coax more power out of as the factory has done their
homework.

Ken





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Rick Harper

Subaru: was Engines and props

Post by Rick Harper » Sat Feb 18, 2012 9:27 am

G'day Mike ;

YES ..... the WR X 2.0 litre DOES in fact put out 220 horsepower
......for very brief periods
AND, yes .... you could probably get 350 horsepower out of the same
engine ..... but in reality , it isn't going to last that long .... it
all comes back to "duty cycle"

The duty cycle of an engine states the percentage of time the engine
will put out the designated horsepower IE: if Lycoming says engine X. X.
X. will produce 160 horsepower ... it means that that engine WILL
deliver 160 horsepower for 100 percent of the time - this is what they
call 100 percent duty cycle
The average car engine by comparison might claim and output of 160
horsepower ... but the duty cycle is usually 30 maybe 40 percent ....
this means that you will only be asking 30 to 40 percent of 160
horsepower constantly (48 to 64 HP) .... An aircraft engine is similar
to a boat engine , in that it needs 100 percent of horsepower to get up
and going .... and then usually, you will back off the throttle and use
around 75 percent of power to continue running .... (75% duty cycle)

The major percentage of car engines would not last very long at all if
this were the environment they had to work in . For example, a very
popular V 8 engine here in Australia , made by general motors , was the
308 eight cubic inch . many of these engines lasted around 300,000mi.
in cars easily ..... which equates to at least 5,000 hours of running .
This same 308 cubic inch Engine was fitted to many speed and ski boats
..... they only lasted 500 to 1,000 hours before they were totally
stuffed .... same engine - different operating conditions !

I do not deny that the Subaru engine is a fabulous engine ..... but
asking 220 horsepower from a 2.0 liter engine is literally "ringing
its neck " !!!

Yes, car engines are far more modern and more fuel efficient than the
Lycosaurus ...... And used in the proper manner you would expect that
they would give 500 to 1,000 hours of reliable use in an aircraft
application ...BUT ....The more horsepower you ring out of a small
capacity engine - the shorter its lifespan is going to be ... NO
EXCEPTIONS !

just my 2


Ken

Subaru: was Engines and props

Post by Ken » Sat Feb 18, 2012 9:27 am

Can you say turbo(s) ? ;)
Yup that short stiff forged crankshaft is a great starting point...
Ken

Mike Davis wrote:
I don't know the first thing about the mods that are made to the
motors...
but the WRX 2.0 liter is 220 HP and on the World Rally circuit they are
getting up to 350 HP out of the same motor... so there are obviously
things
that can be done. Just amazing that they can get that kind of power
out of
those motors and they still prove to be some of the most reliable
motors on
the circuit.

Mike






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Ken

Subaru: was Engines and props

Post by Ken » Sat Feb 18, 2012 9:27 am

Yes indeed except aren't the Lycs in fact rated for something like
only 5 minutes at rated power? I think that is not commonly known but
is in the specs. Of course who runs wide open at sea level at 2700 rpm
for very long? It is almost impossible to run a normally apirated Lyc at
rated power at all without a variable pitch prop as the power falls off
rapidly at less than red line rpm and at higher than sea level.
Ken

Rick Harper wrote:
G'day Mike ;

YES ..... the WR X 2.0 litre DOES in fact put out 220 horsepower
......for very brief periods
AND, yes .... you could probably get 350 horsepower out of the same
engine ..... but in reality , it isn't going to last that long .... it
all comes back to "duty cycle"

The duty cycle of an engine states the percentage of time the engine
will put out the designated horsepower IE: if Lycoming says engine X. X.
X. will produce 160 horsepower ... it means that that engine WILL
deliver 160 horsepower for 100 percent of the time - this is what they
call 100 percent duty cycle

snip






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Wayne G. O'Shea

Subaru: was Engines and props

Post by Wayne G. O'Shea » Sat Feb 18, 2012 9:27 am

The only Lyco's that have a 5 minute limit are the 0-235's that use the 2800
rpm mark to make 7 or so extra hp. Pull back to 2700 and you can stay there
all day long. The other engine is the GSO-480 I have in the UTVA's. 3400rpm
and 48" for 5 minutes = 340HP...but you can run 3200 and 45" all day long at
320HP if you can afford the 50GPH and tolerate the NOISE!

You're very right about the altitude and prop though Ken!..and yes in day to
day life we are usually running around at a 60 to 75% duty cycle, but that's
much higher than my truck running into town and down the 400 at about 25% at
best.

Wayne

----- Original Message -----
From: "Ken" <klehman@albedo.net>
To: <rebel-builders@dcsol.com>
Sent: Monday, August 30, 2004 9:15 AM
Subject: Re: Subaru: was Engines and props

Yes indeed except aren't the Lycs in fact rated for something like
only 5 minutes at rated power? I think that is not commonly known but
is in the specs. Of course who runs wide open at sea level at 2700 rpm
for very long? It is almost impossible to run a normally apirated Lyc at
rated power at all without a variable pitch prop as the power falls off
rapidly at less than red line rpm and at higher than sea level.
Ken

Rick Harper wrote:
G'day Mike ;

YES ..... the WR X 2.0 litre DOES in fact put out 220 horsepower
......for very brief periods
AND, yes .... you could probably get 350 horsepower out of the same
engine ..... but in reality , it isn't going to last that long .... it
all comes back to "duty cycle"

The duty cycle of an engine states the percentage of time the engine
will put out the designated horsepower IE: if Lycoming says engine X.
X.
X. will produce 160 horsepower ... it means that that engine WILL
deliver 160 horsepower for 100 percent of the time - this is what they
call 100 percent duty cycle

snip






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bransom

Subaru: was Engines and props

Post by bransom » Sat Feb 18, 2012 9:27 am

Ken,
Due to living too far south I forget what you guys are flying -- I take it
from your post that you are also Soob 2.5 powered?

I've read the Ron Steber (Contact) articles regarding 25hp increase in 2.2
and 2.5 from cam grind, and yes, when I actually get to FWF, I will see if I
can find this in real life. I wonder if this is the same info you are
referring to. (Let me know if you have other EJ22/25 info sources -- I'm on
the yahoo airsoob group and 99% of that is from EA81 guys!)

To me, the 2.2 is possibly more appealing in a wheel Rebel, and the 2.5 in a
float rebel. I say this because it seems keeping that 20+ lbs off the front
in a wheel Rebel is worth it in keeping the landing speed a little slower.
The minor "problem" here of course is that floats will always be something to
aspire to. When we see articles reporting 137+25hp on a cammed 2.2, plus
some good companies like Crossflow pulling 180 (out of a 2.0?) and more out
of a turbo, its easy to get lathered up about good smooth power at an
attractive FWF weight. Also, all indications are that the Sub can handle
high duty cycle at or above stock HP -- this much I'm convinced of. (not to
worry, I'm not looking for 200hp)
-Ben /496R

<clip>
bit of power. There are believable third party dyno numbers for the 2.2
that are consistent with the factory numbers stock and that show a 25 hp
increase to 160 hp with a cam grind. While I'd definately use a 2.5 if
doing it again, I would realistically not count on more than about 150
hp from the stock normally aspirated engine with modified intake and
exhaust. With expertise and dyno testing you could probably/assuredly do
better but I have seen no convincing evidence of that achievement so
far. Nor would I expect an extra 25 hp from cam grinds like in the 2.2.
By all accounts the 2.5 is an excellant 0-320 alternative but it is
already a highly tuned engine with little to be gained by mods from what
I understand.

OTOH if you are burning and carrying less fuel and perhaps have a lower
drag cooling system, it may be as good as having some extra power ;)

Ken



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Ken

Subaru: was Engines and props

Post by Ken » Sat Feb 18, 2012 9:27 am

Hi Ben

No I've converted a 2.2 and am trying to wire it as we speak. The 2.5
was not really available when I started so I've made some provisions to
add a touch of nitrous to the 2.2 for small lakes when I get the floats
built ;)
I figure I can have the power without the weight or other complications
of a turbo. Most of the time I will leave the nitrous bottle at home and
enjoy the reliability of a stock engine.

Yes indeed I was referring to Ron's dyno stuff and also some comments by
Reiner who did all the original Stratus development as well as some
other contacts over the last 7 years. I haven't tuned in to airsoob for
several years.

It's been an adventure! Hope it works as it has added several years to
the project ;)

Ken

bransom@dcsol.com wrote:
Ken,
Due to living too far south I forget what you guys are flying -- I take it
from your post that you are also Soob 2.5 powered?

I've read the Ron Steber (Contact) articles regarding 25hp increase in 2.2
and 2.5 from cam grind, and yes, when I actually get to FWF, I will see if I
can find this in real life. I wonder if this is the same info you are
referring to. (Let me know if you have other EJ22/25 info sources -- I'm on
the yahoo airsoob group and 99% of that is from EA81 guys!)

To me, the 2.2 is possibly more appealing in a wheel Rebel, and the 2.5 in a
float rebel. I say this because it seems keeping that 20+ lbs off the front
in a wheel Rebel is worth it in keeping the landing speed a little slower.
The minor "problem" here of course is that floats will always be something to
aspire to. When we see articles reporting 137+25hp on a cammed 2.2, plus
some good companies like Crossflow pulling 180 (out of a 2.0?) and more out
of a turbo, its easy to get lathered up about good smooth power at an
attractive FWF weight. Also, all indications are that the Sub can handle
high duty cycle at or above stock HP -- this much I'm convinced of. (not to
worry, I'm not looking for 200hp)
-Ben /496R





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Gordon Mohr

Subaru: was Engines and props

Post by Gordon Mohr » Sat Feb 18, 2012 9:27 am

Just a note to all who are trying to get more power from the
Legacy. The turbo 2.2 does not use the same block as the standard 2.2.
They reinforced it to handle the extra power and pressure. I doubt if
they would have done that if they didn't deem it necessary.
I've been considering nitrous for the same reason as you Ken. Let
me know how it works out.

Gordon Mohr

Ken wrote:
Hi Ben

No I've converted a 2.2 and am trying to wire it as we speak. The 2.5
was not really available when I started so I've made some provisions to
add a touch of nitrous to the 2.2 for small lakes when I get the floats
built ;)
I figure I can have the power without the weight or other complications
of a turbo. Most of the time I will leave the nitrous bottle at home and
enjoy the reliability of a stock engine.

Yes indeed I was referring to Ron's dyno stuff and also some comments by
Reiner who did all the original Stratus development as well as some
other contacts over the last 7 years. I haven't tuned in to airsoob for
several years.

It's been an adventure! Hope it works as it has added several years to
the project ;)

Ken

bransom@dcsol.com wrote:





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Gordon Mohr

Subaru: was Engines and props

Post by Gordon Mohr » Sat Feb 18, 2012 9:27 am

When Subaru came out with the legacy, they ran a stock vehicle on a
test track at a continuous speed of 120 mph 24 hours a day for a week,
only stopping for fuel and to change drivers. When they tore it down
there was no measurable wear. That is triple the certification
requirement for an aircraft engine. Sure, cars don't normally run at
continual high power settings, but constant acceleration/deceleration is
a lot harder on an engine. How long would an O-320 last in a car
driving around town? I know of many a cracked cylinder and very low TBO
from glider towing.
The reason Lycomings etc are rated for continuous "full power" is
that it is a massive displacement engine that is drastically under tuned
to turn slowly for prop efficiency. In effect, they are only running at
half throttle when they are wide open. The same displacement engine in
a car would put out nearly twice the horsepower and, yes run at 25% most
of the time.
Gordon

Wayne G. O'Shea wrote:
The only Lyco's that have a 5 minute limit are the 0-235's that use the 2800
rpm mark to make 7 or so extra hp. Pull back to 2700 and you can stay there
all day long. The other engine is the GSO-480 I have in the UTVA's. 3400rpm
and 48" for 5 minutes = 340HP...but you can run 3200 and 45" all day long at
320HP if you can afford the 50GPH and tolerate the NOISE!

You're very right about the altitude and prop though Ken!..and yes in day to
day life we are usually running around at a 60 to 75% duty cycle, but that's
much higher than my truck running into town and down the 400 at about 25% at
best.

Wayne





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Ken

Subaru: was Engines and props

Post by Ken » Sat Feb 18, 2012 9:27 am

Hi Gordon

Quite right! I think the biggest difference was oil spray jets to cool
the piston undersides on the turbo block. Unfortunately that block has
been out of production for 10 years now. I believe it was closed deck
too but that feature seems to come and go a bit and may not be all that
significant. And of course it had the water and oil feeds to the turbo
and a lower compression ratio.

With nitrous we don't have the complications of a hot intake charge. For
short bursts of nitrous the main issue and limitation is a free flowing
exhaust from what I can see. I did set up my second igintion to run
slightly retarded over the normally aspirated oem system. Most of the
car kits don't even do that. I honestly don't think the NA engine will
even notice an occasional perhaps 25 hp shot of nitrous as far as wear
and longevity goes...

Ken.

Gordon Mohr wrote:
Just a note to all who are trying to get more power from the
Legacy. The turbo 2.2 does not use the same block as the standard 2.2.
They reinforced it to handle the extra power and pressure. I doubt if
they would have done that if they didn't deem it necessary.
I've been considering nitrous for the same reason as you Ken. Let
me know how it works out.

Gordon Mohr





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