18hp + Nitrous , for higher altitude

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
Warning: Shameless, Machiavellian, Greedy, Greasy, Capitalist Pig profit-making ulterior motive in full-throttle use:

Bille, I may have an engine that you would be interested in. It is the KFM 30HP 2 stroke boxer, WITH the later belt reduction drive and starter. This is very light and is capable of powering a rigid wing glider like your ATOS (or was it an Exxtacy???) up at the altitudes you're interested in. It would give you excellent takeoff and climb performance, as well as a higher service ceiling.

(sound engineer, cue the Pink Floyd cash registers)

Normally, people would be hoarding and panic-buying these engines like toilet paper, and you'd have to fight your way through hours of standing in line, only to find that they're all sold out.

But not today at The Great L. Cheapo's Aircraft Supply Emporium! We have one left in stock with your name engraved on it.

Just think of yourself soaring above all the hordes of zombies down below screaming "Soylent Green is people!"

PM me if interested.
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
After 6 hours of sleep ; i changed my mind about getting the Moster 185+.
I want more hp.

Kinda looks like dog was correct ! :)

...
you are now officialy a gear head.no getting around it.nitrous and alcohol
injection and gasoline and full power, your a gear
head, welcome to the eternal quest for more zoom

Bille
 
Last edited:

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,227
Location
AMES, IA USA
That is exactly what John said ; the owner of the airport, at the base
of King mountain.
I can pick up a new Moster 185 plus, with redrive clutch and starter
for about $3K ; so it's hard to argue with what ya just said !

Given a choice , I would prefer, a twin apposed , over a single cylinder
thumper ; they run a lot smoother. I wonder how big the crank is on the Moster ?

Bille
===============================

BHP of 21 at sea level and Elevation of 5000 feet is 3.15 HP loss. 21hp - 3.15hp = 17.85hp!

You can Buy a Rotax 185UL off eBay right now for $300.

(62mm x 61mm) 184.2cc/7cc = 26.3hp@6500rpm.

A Skidoo 250 Type 253 Single is 22hp@6000rpm.

Any of the Old Skidoo/Rotax Singles could be made to work, used $50-$125.

250 Type 247
292
299/300
318/320
335/340

Plus the 277UL.
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
Johns airport , sits at 5,500 ASL ; he said i need 25hp to do the
job , with some reserve.

I thought the 185UL was way lower hp ; it was the 277UL that puts
out 25hp ? The 277 with redrive , is much too heavy ; max i would
even consider is 45 to 50Lb (35 to 40Lb) would be more like it.

Bille
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
...

Bille, I may have an engine that you would be interested in. It is the KFM 30HP 2 stroke boxer, WITH the later belt reduction drive and starter. This is very light and is capable of powering a rigid wing glider like your ATOS (or was it an Exxtacy???) up at the altitudes you're interested in.
...
I did a fair search for parts on that engine ; nothing available, but i
could be wrong ?
I saw your add in Homebuilt ; $-2500 is way too much , for an engine
that ya can't get parts for .

I would be interested in purchasing the belt redrive off it though though ?

Bille
 

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
I saw your add in Homebuilt ; $-2500 is way too much , for an engine
that ya can't get parts for .
Oh no... you're not getting off my fish hook line that easy. You haven't seen the "End of the World" Pandemic Pandemonium Price yet...

And numerous additional discounts are available, including SPECIAL pricing for:
  • Hang Glider pilots
  • Kiteboarders
  • Army Intel veterans
  • People with composite body parts

(Let me know when you are actually read to buy it, and I'll make you happy on the price. But wait until you're ready to do business - as an experienced salesman in another lifetime, I learned how to defeat "I'll think about it", "Let me talk to my wife about it", and "I have several other options to cmpare this to".)
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
...

(Let me know when you are actually read to buy it, and I'll make you happy on the price. But wait until you're ready to do business - as an experienced salesman in another lifetime, I learned how to defeat "I'll think about it", "Let me talk to my wife about it", and "I have several other options to cmpare this to".)
My blond neighbor ; she already made me Happy !!
Sorry ----- couldn't resist . LOL

Shut-UP Bille ; don't piss off the guy who can make that dream
of flying King Mountain , from off my buddy's airport , (actually come true) !!!!

Bille
 

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
How about this... show me on a map where King Mountain is and where your friend's airport is. I'll tell you honestly whether there is a goor or bad chance that this KFM engine would help accomplish what you want, or if you are better off with something else.
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
How about this... show me on a map where King Mountain is and where your friend's airport is.
...
King Mt Glider park ; elevation 5,503'


John usually holds a glider Safari in June ; but his wife is
kinda sick and he had to postpone this years event. It's
an 83 mile long Mt range ; and he gets permission to open the wave-window
to fly high enough to die without Oxygen.

And when Ya talk to your wife ; please show her this article about me, and
what i do on my fake legs :


Screenshot 2020-03-25 at 2.53.05 PM.png
 

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
Yeah I read that article, that's how I found those four things about your background :)

That airport looks to be maybe 3000 feet long. At 5000 ft MSL I'm guessing a 25-28 HP engine is going to be right on the edge of allowing you to take off safely and establish any realistic rate of climb. On a warm day probably not, on a cold morning maybe yes.

You do have light weight in your favor, the hang glider weighs a lot less than a sailplane. But you would definitely need to tune the engine and propeller for that specific environment.

If you want to fly a rigid wing HG from that airport, IMO you can forget about anything other than a very good wheeled takeoff dolly, or a weight shift buggy like a trike or PPC has.

To make your dream come true with the best chance of success, I would suggest that you cheat a little... or a lot:

Have an engine mounted on the rolling buggy, mount it as a pusher, typical of a trike. Then have a hard point at the front of the buggy with a glider tow release. Put a 200 foot tow rope on a car or pickup, ad have the car tow you (also using full engine power on the glider) to accelerate, take off and climb to 10 or 20 feet AGL quickly, just like they do with scooter tows or winch tows at Wallaby Ranch.

After the tow car has gotten you up to speed and off the ground, and on the good side of the lift/drag/power curve, then release the tow line. The engine and propeller are already in the range to provide thrust. Then you can climb out and get to your wave or ridge.

BUT, with marginal power and climbing slowly, typical sink and wave rotors would easily overcome the glider's ability to climb. The "down" side of a wave rotor can stop a 235HP Piper Pawnee from cimbing, so there is a clear possibility you can be put in a pretty difficult position while try ing to reach the wave.
 

Armilite

Well-Known Member
Joined
Sep 5, 2011
Messages
3,227
Location
AMES, IA USA
Johns airport , sits at 5,500 ASL ; he said i need 25hp to do the
job , with some reserve.

I thought the 185UL was way lower hp ; it was the 277UL that puts
out 25hp ? The 277 with redrive , is much too heavy ; max i would
even consider is 45 to 50Lb (35 to 40Lb) would be more like it.

Bille
===================================

If it Flies well with 18hp at Sea Level, at 5500'. What rpm is it turning to make that 18hp? What does it Weigh?

What is the Prop Spec's you're using at Sea Level? What is your Reduction Ratio?

BHP of 22hp at sea level and Elevation of 5500 feet is 3.63 HP loss. 22hp-3.63 = 18.37hp! A Skidoo 250 Type 253 is 22hp@6000rpm with a Muffler.

BHP of 23 at sea level and Elevation of 5500 feet is 3.80 HP loss. 23hp-3.80 = 19.2hp!

BHP of 24 at sea level and Elevation of 5500 feet is 3.96 HP loss. 24hp-3.96 = 20.04hp!

The Stock 185UL was 9.4hp@5000rpm ran usually in Direct Drive mode, some did use a Reduction Drive. It also used a Low CR and Small Carb. The PTO is 7/8" = 22.225 mm. The Skidoo 250 Type 253 and the 277UL use a 30mm PTO. You could run either one in Direct Drive Mode to Save Weight & Money.

A 2 Stroke, if Built with 11.5cr, use proper Size Carb and use a Good Designed Wide Band Tuned Pipe at 6500rpm it takes on Average 7cc to make 1hp!

A 185UL is (62mm x 61mm) 184.2cc / 7cc = 26.3hp@6500rpm! The 185 is still made today for Water Pumps, so parts are available. A bunch of these 185UL's were dumped on eBay recently by an old Lazair Dealer.

If you want 25hp x 7cc = 175cc+ if using a Tuned Pipe. JLO & SACHS made about 14 different Singles each. Skidoo had about 10 different Singles.

The Skidoo 250 Type 253 would be a better Engine account it already uses CDI, has a Thicker 30mm PTO. Used, anywhere from $50 to $350.

Older Skidoo Singles also used a 7/8" Straight PTO. It's possible on some Older Skidoo Singles to upgrade the PTO. Most of them used either 61mm, or 66mm Stroke or 70mm Stroke. If you can find a CASE like this, it can be upgraded. I think I paid $75 for this lower.

340 Single Upgraded to a better HD PTO 70mm Stroke Crank.
340 CASE ZOOM IN PTO.jpgSki Doo TNT & Blizzard 340 single BILLET CRANK.jpg
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
...

If you want to fly a rigid wing HG from that airport, IMO you can forget about anything other than a very good wheeled takeoff dolly, or a weight shift buggy like a trike or PPC has.

To make your dream come true with the best chance of success, I would suggest that you cheat a little... or a lot:
...
YEP , i'm designing a low profile wheel, with retractable drag sticks, to keep
the wings level on the ground. I also want a very clean pod , to hide the
pilot. I'd rather not rely on another human ; to tow me up ! That's a Definite (.)
Here is what i have to work with :
Span --------------------------------------40'
aria-----------------------------------------160 sq/ft
L/D ----------------------------------------17.5 : 1
AR------------------------------------------10
VNE ---------------------------------------58-mph in turbulent air
Empty weight ----------------------------100 Lb
Max pilot / passenger weight ---------358 LB
MY Fat A$$ weight =============210 Lb

To stay in the VNE weight ; i have ---148 Lb , for the engine / mount / prop
pod , landing gears , with parachute, and gas. If i do that ; i also stay 103
compliant.

You see why i need a light engine with the redrive ?
The pod---
lucky i'm good at mold making , and can beat any glass foam structure
with carbon and Nomex honeycomb , for strength and weight. Nomex
is a bear to work with ; but WOW the results are awesome. The glider
D-tube , is made in carbon and Nomex ; i'm not worried about it breaking
as long as i stay within the VNE weight / speed. I expect my L/D to go to
near 22:1 when finished ; that's rather low for sailplane standers
but i was just fine flying in a SGS 1-26, and thought it was a Blast !!!

Bille

PS :
What do you guys think of the Hirth F-33 ?
 
Last edited:

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
The KFM engine I have is probably going to be about the best compromise between power/weight ratio and cost of purchase.

You can get higher power/weight by using a more modern paramotor engine (Simonini, Polini) but the engine will cost you 3X the amount that I'm trying to pry out of your wallet. So if engine cost is an equal part, then the KFM is a decent choice.

Be conservative with HP and "static thrust" numbers, with a pusher propeller right behind the pilot you are not going to get perfect air flow into the propeller. You'll notice that all those youtube static thrust test videos don't have a 200 pound pilot strapped in right in front of the propeller :)

If you are flying out of a gliderport, and they are launching gliders because there is a wave window, there is going to be someone there running wingtips, flying the towplane, and hooking up the towropes. Desires and dreams notwithstanding, you may not actually be able to do all of this without somebody else involved for a couple of minutes.
 

Bille Floyd

Well-Known Member
Joined
Sep 26, 2019
Messages
199
...

Be conservative with HP and "static thrust" numbers, with a pusher propeller right behind the pilot you are not going to get perfect air flow into the propeller. You'll notice that all those youtube static thrust test videos don't have a 200 pound pilot strapped in right in front of the propeller :)

...
If i keep this a flying wing , then a tractor folding prop, would work Great ; especially
if a gain a bit of efficiency, by using it. All i need to do is rethink my landing gear, and
push the pilot back a bit t, o counterbalance the engine .

At that weight you are in "micro-lift" glider territory, depending on your airfoil and stall speed.
It won't be a micro-lift glider , when it's done ; it was built to handle 358.4 Lb
of pilot and passenger weight .

Bille
 
Last edited:

Victor Bravo

Well-Known Member
Joined
Jul 30, 2014
Messages
7,042
Location
KWHP, Los Angeles CA, USA
If you want to go tractor, see if you can mount the engine above the leading edge apex of the wing, so the propeller has as much ground clearance as possible. Then you can have the shortest, lightest possible wheel. This will require you to put some effort into keeping (your head or your feet, depending) out of the prop arc. Also, the thrust line cannot be high enough to cause other problems...
 
Top