JFS100 TURBINE GOOD OR BAD?????
Flygyros
TIME WITH IT, I DONT WANT TO HEAR THAT I GUY THAT KNEW A GUY THAT HEARD ABOUT
IT, THAT IT WAS A BAD TURBINE, NO I WANT TO HEAR FROM GUYS WITH DIRECT CONTACT
WITH THE JFS100, IF YOU GUYS CAN HELP WITH GOOD INFO I WILL BE MOST THANKFUL.
STEVE
Juan Jimenez
exact conditions in which it is recommended to run them, so be it. Go
ahead and put one in your bird. It's your butt. If you want to see the
message sent to me by the person who was running the test, describing
exactly what happened, then email me at fly...@home.com.
Andrew Russell
Using all capitals in messages is very hard to read and is considered the
equivilant of shouting. Find that caps lock key and whap it a good one!
Re the JFS100: Here's some info from an Allied Signal engineer that was
posted here a couple of years ago. There are a lot of good reasons not to
use an APU for aircraft propulsion, and Mr. Johnson is worth paying
attention to. Good luck.
***************************************
From: b17...@vaxb.phx1.aro.allied.com
Newsgroups: rec.aviation.homebuilt
Subject: Re: Solar T62-2A1 turbine unit, and JFS100
Date: 12 Dec 95 07:34:15 MST
Organization: AlliedSignal Engines
Lines: 30
Message-ID: <1995Dec1...@vaxb.phx1.aro.allied.com>
References: <4aibmq$1t...@news-s01.ny.us.ibm.net>
NNTP-Posting-Host: vaxc.phx1.aro.allied.com
In article <4aibmq$1t...@news-s01.ny.us.ibm.net>, man...@ibm.net writes:
> [snip]
> There is also another turbine unit some guys are putting in a KR2.
> It is made by Allied Signal and is called a JFS100.
> This one has twin turbines, one to operate the compressor,
> the other drives the gearbox. This way, an adjustable prop is not
> needed, (similar in design to the Pratt&Whitney PT6).
>
> Comments? Opinions? Suggestions?
>
[snip]
>
> -- Sidney Rhodes
> LongEZ 19SH
>
My comment is that putting a JFS100 in a KR2 is not a good idea. The
JFS100 is a Jet Fuel Starter and is used to start the engines in an F-15.
The unit has a design duty cycle optimized for many short duration
start/stop cycles and is not designed for operating for any appreciable
duration. Putting this unit in an airplane as a propulsion engine would
subject it to more abuse that it was ever designed for (and it dosen't do
all that well in the F-15 as it is). Stick with a converted car engine,
it'll be a lot safer.
Mark Johnston
Sr Development Specialist
Military Engine Enterprise
AlliedSignal Engines
Phx AZ
************************************************************
Andrew Russell
arus...@bix.com
River - Xtreme Aviation
>JFS100 is a Jet Fuel Starter and is used to start the engines in an F-15.
>The unit has a design duty cycle optimized for many short duration
>start/stop cycles and is not designed for operating for any appreciable
>duration. Putting this unit in an airplane as a propulsion engine would
>subject it to more abuse that it was ever designed for (and it dosen't do
>all that well in the F-15 as it is). Stick with a converted car engine,
>it'll be a lot safer.
>
>Mark Johnston
>Sr Development Specialist
>Military Engine Enterprise
>AlliedSignal Engines
>Phx AZ
>
>************************************************************
>
>
>Andrew Russell
Andrew,
I'm no expert, and I can't tell you how hard it is for me to get into another
pissing match, but this is only the info I KNOW. The JFS was origonally a
starter engine for the A-7. The F-15 I've heard has a completely redesigned
engine only similar to the JFS. There have been a lot of problems with JFS
engines, but the problems are getting solved. There are two in Mini-500
helicopters right now, in fact, maybe three. They have problems with cooling,
but those problems are getting solved. There is a guy who hovers his Mini for
short periods of time and the engine does fine except for getting a little hot.
As with the case of the KR, I'm not sure exactly how it is set up, but the KR
pilot took it apart and told Jim Vos that it showed "no noticable ware." And
that was after 100 hrs! It is a matter of setting it up right, and making sure
you test and fix your cooling problems.
Jim Vos is doing excellent work getting these engines better for aircraft use.
He has done his best, and with the proper installation and ventalation, these
engines have a lot of potential. All of the problems with the JFS are
attributed to cooling in one way or another. People who can think out cooling
strategies and ways to mount the engine with good air-ducts, I think this
engine is awesome.
River
"Xtreme...Life is too short not to be!"
In memory and honor of Allen Barklage...One of the greatest pilots to ever set
foot on this earth!
Juan Jimenez
tests of the JFS-100. This test was conducted in Arizona late last year.
Hey Juan
If anyone contacts you regarding the Garrett engine in a BD do what you
can to discourage them. I have been playing around with that engine for
quite some time. We recently finished all of the
lubrication and throttle modifications and were just using it for
demonstration purposes. Well
We were playing with it last night as we were going to take it to the
EAA show here this weekend.
I fired it up and let it run for about 10 minutes ( 48 minutes is the
longest that we had it running) and all of a sudden KA BOOM. Man was
that loud. It blew the entire back end off
the thing. It was only at 68% There are guys trying to sell these things
in Kit Planes and elsewhere to unsuspecting buyers. Beware these engines
are starter engines. The tech manual says
that they can be run for 10 minutes at a time to spin up the main engine
for tests and such. These guys are trying to say that by increasing the
oil supply and adding a cooler that the engine will go
for 1200 hrs. WRONG. Allied Signal says 1200 starts not hrs. Some of the
internal parts are not
intended for continuos use as the specifications for creep and thermal
expansion are greatly exceeded. I had intended to put the thing out back
of the shop, fire it up, and let it run and see how long it lasted but I
guess that is now not on the drawing board. Sure makes a neat
little conversation piece. Do not be fooled BDers. This is not for you.I
can hardly wait for the Teledyne to let go at full tilt. I only hope
that I am in a different city when that happens.
-----
(For the record, the Allied Signal version of the JFS -is- the allegedly
redesigned and improved JFS100. The original manufacturer of the JFS was
Garrett. Those engines are even less suited for use as primary
powerplants.
Comments from another good friend of mine who uses the Solar engine as
the basis for a turboprop engine and evaluated the JFS-100 quite
thoroughly. His name is Richard Karnes and he's the owner of BD Micro
Technologies in Siletz, Oregon (sa...@bd-micro.com)
-----
>In reply to the statements made by a gentleman not recommending the
>use of the Garret JFS100 turbine starter engine. He agrees
>with what we have been saying for a long, long time about this
>engine being used as a powerplant. The JFS100-13A turbine starter is
>an engine that we examined as a potential bases for a turboprop
>powerplant. We quickly discarded this engine as a possibility
>because of its many shortcomings. This is the main engine starter
>for the A7D jet fighter and was NOT designed for continuous duty. A
>direct quote from the JFS100 Spec. book says, "Leading particulars
>for the Jet Fuel Starter,... Operating Life - 1200 starts. Duty
>cycle - The starter is capable of making three consecutive start
>cycles with a time interval of one minute between the completion of
>one cycle and the initiation of the next cycle. If three consecutive
>starts are conducted, wait 40 minutes before conducting the next three
>consecutive starts to allow starter to cool. No more than six start
>cycles are recommended within a one hour period. Motoring cycle -
>The starter is capable of motoring the main engine for periods of two
>minutes duration, followed by a normal start cycle within five
>minutes. It is permissible to make three consecutive motoring cycles
>during a one hour period. The starter is capable of motoring the
>main engine for a period of five minutes." I receive many telephone
>calls about this engine. I try to explain to the caller why this
>engine is totally unsuitable as a powerplant in six specific areas.
>1) It is a non-continuous duty engine. It is NOT an APU which are
>designed to run continuously such as our Solar T-62 based Quantum
>H-95 turboprop engine. It has a very limited start life and can be
>run for minutes at a time only. It only has a 9.3 ounce oil capacity
>(a glass of water). Increasing the oil capacity does not extend the
>inherent short life of this engine.
>2) It is a free turbine with no provision for governing the output
>shaft. The output shaft RPM at full stated horsepower of 90 is
>8,000. Way to high for any practical use, especially in a BD-5.
>There is no practical "throttle" system on this engine. It is simply
>a fuel solenoid that opens at a programmed time and sends fuel
>through nozzles with no provision for controlling engine RPM. The
>engine was designed so that when it started, the free turbine output
>shaft started to spin the main engine. When the main engine hits
>idle RPM the Jet Fuel Starter Motor shuts off. That is why it is
>called a load governored engine. It operates against a load and
>does not have to be governored. To hook it to a propeller, you will
>have to engineer, design, build, and test basically two governor
>systems. One for the propeller and one for the engine. Sounds fun
>doesn't it.
>3) It has a 28 volt small starter and generator. The generator is
>an unregulated axial-gap, permanent magnet, AC generator.
>4) It uses specialized and expensive parts. There is absolutely no
>factory support or new parts availability. If you want spare parts
>you will need to buy more than one engine.
>5) It requires specialized engine monitoring instrumentation that is
>not available.
>6) It is a difficult engine to work on, and requires specialized
>tools to maintain.
>Can it be used as a turbojet engine for the BD-5, as I am so often
>asked. No. Its only virtue as a powerplant source is its cheap and
>makes a great conversation piece when your friends come to visit.
>But, as the comic once said, "You pays your money, you takes your
>chance."
>
----
And one more, received just few days ago:
----
I own one and have it mounted on a Bensen airframe, but I haven't flown
it yet.
THIS IS ABSOLUTELY THE **WRONG** "ENGINE" FOR A SERIOUS PROJECT!!!!
It is a *starter motor*, nothing more- the output gearbox is
completely immersed in the exhaust plenum, and cannot be cooled- this is
why they are limited to 5 minutes of run time out of an hour.
The guys who have installed them on fixed wing airplanes have gone
through 5 at last count- the gearboxes shred when the oil cavitates.
DON'T be confused by the ultralights that are using only the gas
generator-these JFS 100s have a separate power section, and that's where
the problem
lies. If you care to remove it, you can use the rest of the engine- the
gas generator- as a pure jet, but it won't do you any good on a
helicopter.
DO *NOT* try to use the JFS-100 as a helicopter powerplant!!!! I'm
only going to fly it on the Bensen a very few times and for a very few
minutes, strictly for "bragging rights". It is *not* a "serious"
project!
I did post a picture of this project some time ago in the Rotorcraft
Conference Forum. You might search for it. It's practically a drop-in
replacement for the Mac.
----
I don't think there's anything here that even remotely suggests that the
engine is "awesome".
Juan
River - Xtreme Aviation
Juan Jimenez
knowledge of this engine.
Rich Ahrens
> I refuse to have a battle of knowledge (and witts) with an unarmed person.
Pretty amusing coming from a twit who cannot even spell a one-syllable
four-letter word correctly.
------------------------------------------------------------------------
|Rich Ahrens | Homepage: http://www.visi.com/~rma/ |
|r...@visi.com |-----------------------------------------------|
|"In a world full of people only some want to fly - isn't that crazy?" |
------------------------------------------------------------------------
GRay
>
>
> River
Hmm, Witts, or wits?
Egad:)
ObSigh: Sigh.
--
GRay-
Kill the extra "g" for mail.
"I went apeshit." Alraune
Bob U.
>River - Xtreme Aviation wrote:
>> I refuse to have a battle of knowledge (and witts) with an unarmed person.
>
>Pretty amusing coming from a twit who cannot even spell a one-syllable
>four-letter word correctly.
>
>|Rich Ahrens
++++++++++++++++++++++++++++++++++++++++++++++++++++++
For more amusement, check him out in the aerobatic NG.
He either practices on us for them or vice versa......
or is it the rotor guys?
< Sigh >
Bob U.
Lennie the Lurker
wingm...@aol.com (River - Xtreme Aviation) wrote:
>
> I'm no expert, and I can't tell you how hard it is for me to get into
another
> pissing match, but this is only the info I KNOW.
Wingy, I haven't jumped on you on this topic yet, but it's now my turn.
Your enthusiasm is great, and should be encouraged, BUT.
It is indeed possible to re-engineer any engine to any purpose, but
again, what is possible and what is practical are usually two different
breeds of animal. From what I've been reading here, by the time this
engine could be made safe and reliable, it would be cheaper and more
efficient to design one from scratch, and not have to deal with the
pitfalls of the existing design.
Many years ago Les Long designed an engine, two cylinder opposed, made
from Harley cylinders and pistons. All it required was casting a
crankcase, then turning and grinding the crankshaft, then the gearing
for the cams, etc. etc. The end result was a fairly good 40hp four
cycle engine operating in the rpm range required for the aircraft.
Practicalities of today are somewhat different, Harley cylinders are no
longer easy to come by, and not cheap. Casting the crankcase would
probably cost more than the rest of the engine, then several hundred
hours of machining time at today's rates, and it may be possible, but
certainly not practical. Finding the billet of steel to make the crank
may not be a problem, but finding someone with the facility to grind it,
as a "one off", is going to be a problem.
The engine may be a basis for a re-design, but from what I'm reading
here, it's not a jump off to a simple modification to a reliable engine.
Hi temp alloys are not nice to machine, not cheap, and not always easy
to find. True, with enough work and lots of expensive work, it may be
possible to re-design the engine, but is the end result going to be
worth the effort or would it be more practical to start with a blank
page and go from there? Enthusiasm and dreams are great Wingy, but to
get the practical, you have to mix in hard reality.
Richard B.
--
http://homestead.deja.com/user.rabue/index.html
Another page, another disease.
Views are my own, get yours yourself.
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Bob U.
>> I'm no expert, and I can't tell you how hard it is for me to get into
>another
>> pissing match, but this is only the info I KNOW.
>
>Wingy, I haven't jumped on you on this topic yet, but it's now my turn.
>Your enthusiasm is great, and should be encouraged, BUT.
Sorry.
Better men and a woman could not put a dent in this lad's cranial armor.
I'll bet a dollar to your donut, you fall flat on your face with this latest
attempt to give this youngster an honest dose of reality.
My crystal ball sez...
When the smoke clears, YOU will get a bigger BUT than you could ever give him!
Trust me, I have seen Wingster in action too many times.
It's ALWAYS the same.
As guessin' man with a pretty good average,
I'd say your talking to the wall for a minimum of 7 years.
If I'm wrong, I'll owe you an apology at that time plus the buck. <g>
If not... you owe me a donut on July 8, 2006.
Guido has been notified.
Just to CEMENT the deal. <g>
Bob U.
Lennie the Lurker
ruokR...@mindspring.com (Bob U.) wrote:
>
>
> I'll bet a dollar to your donut, you fall flat on your face with this
latest
> attempt to give this youngster an honest dose of reality.
Time will tell, you may be right.
>
>
> Trust me, I have seen Wingster in action too many times.
> It's ALWAYS the same.
His enthusiasm is wonderful, and he's gaining knowledge, but still has a
ways to go. Youth, it's wonderful. Too bad it's wasted on the young.
>
> As guessin' man with a pretty good average,
> I'd say your talking to the wall for a minimum of 7 years.
I was about to question this, but then saw the "minimum".
>
> If I'm wrong, I'll owe you an apology at that time plus the buck. <g>
> If not... you owe me a donut on July 8, 2006.
Go ya one better, I fill the tanks on your "coupe" at Osh, we fly to
Burlington, head for Hermans sausage, and have some of the best brats
that man or beast has ever consumed.
>
> Guido has been notified.
> Just to CEMENT the deal. <g>
Tell him he's looking for Attila the Hun. Wouldn't want him to come
unprepared.
>
> Bob U.
>
>
Been chopping metal all afternoon, turning a piece of 6 inch dia. by 3
inch long 1045 into a prop hub. All that's left is cut a keyway and
drill the bolt holes. Don't mind it when I miss by a little, but I
missed the first one by 1 1/2 inches. Dumbkopf comes to mind readily.
Bob U.
>> Guido has been notified.
>> Just to CEMENT the deal. <g>
>
>Tell him he's looking for Attila the Hun. Wouldn't want him to come
>unprepared.
>>
>> Bob U.
>>
>>
++++++++++++++++++++++++++++++++++++++++++
Attila the Hun, eh?
Thats the bad dude that uses them knives, swords, axes and hatchets?
Not to worry....
Guido never brought no stinkin' knife to a gunfight!
>Been chopping metal all afternoon, turning a piece of 6 inch dia. by 3
>inch long 1045 into a prop hub. All that's left is cut a keyway and
>drill the bolt holes. Don't mind it when I miss by a little, but I
>missed the first one by 1 1/2 inches. Dumbkopf comes to mind readily.
>
>Richard B.
No need to beat yourself up like this......
Let us do it!
Bob U.
Lennie the Lurker
ruokN...@mindspring.com (Bob U.) wrote:
>
> Certainly, Sir. have at it. I got this the old fashioned way. I
EARNED it!
Richard B.
>
> No need to beat yourself up like this......
> Let us do it!
>
> Bob U.
>
>
--