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May 23, 2019, 03:59 PM
Registered User
Thread OP
Question

Norvel .074 vs. O.S. .10 schnuerle ported


Would a Norvel .074 have the same or more power than an O.S. .10 ? I have a 36" thin winged racer that originally was electric powered and I have a
new O.S. .10 I have owned for 40 years now . It seems a little heavy for the airplane . These airplanes were sold years ago it kind of looks like a mini
Spitfire . I think they were called Swallows . I think it would be a screamer with the Norvel .
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May 23, 2019, 05:21 PM
ffkiwi
Quote:
Originally Posted by Rocket_88
Would a Norvel .074 have the same or more power than an O.S. .10 ? I have a 36" thin winged racer that originally was electric powered and I have a
new O.S. .10 I have owned for 40 years now . It seems a little heavy for the airplane . These airplanes were sold years ago it kind of looks like a mini
Spitfire . I think they were called Swallows . I think it would be a screamer with the Norvel .
I've never seen test performance figures for the Norvel-but the data for the OS 10 can be found on line:

http://sceptreflight.com/Model%20Eng...010%20FSR.html

I would expect the Norvel to be in the same ballpark-but possibly peaking at a higher rpm than the OS....requiring some adjustment to prop load. Where the Norvel would really win is in the weight stakes-being significantly lighter than the OS. In the debit column though you would have to figure out whether you wanted the hassle of dealing with glowheads-though there have been adaptors made for the Norvel which take turbo plugs....

ChrisM
'ffkiwi'
May 23, 2019, 09:56 PM
Nitro Abuser
Amp Abuser's Avatar
The lower weight Norvel .074 would certainly be worth a go!
Really the best solution with the plane described, the cased .10 seems to be
overkill in weight. Can you post a pic of the plane?

My tests with the .074:

Norvel .074 / APC 6x4 - 17,603 rpm / 30% Nitro 20% Castor (1 min 26 sec)


AmpAbuser
Published on Oct 19, 2016
Stock Norvel .074 / APC 6x4 / 160 deg exhaust timing
17,603 rpm / 19oz thrust / .203hp / 151.4w / 67 mph
30% Nitro 20% Castor

For Speed:
Norvel .074 with new Norvel Turbo Plug adapter 5x4.5 / 22.77K rpm (0 min 57 sec)


AmpAbuser
Published on Dec 11, 2017
Norvel .074 / HQ 5x4.5 carbon / Modified Heli muffler / Turbo O.S. P6 Plug / Norvel Made Adapter
Static 22,771rpm / 14.81oz / .239hp / 178.3w / 97 mph / 25% nitro 20% castor

Best balance of thrust / speed:
Norvel .074 / Heli Muffler / HQ Prop 5x4.5 Carbon 85 mph static. (1 min 9 sec)


AmpAbuser
Published on May 6, 2017
Norvel .074 static stats: 30% Nitro 20% Castor
APC 6x4 - Modified Heli Muffler 19,147 rpm / 196w / .262hp / 22oz thrust / 73 mph


OS .10 FSR 146 deg timing
No muffler:
18,000 / .275 hp / 40% nitro ( per Peter Chinn)
18,000 / .240 hp / 5% nitro
With muffler:
17,500 / .225hp / 40% nitro

VS

Thunder Tiger GP-10 160 deg timing

With exhaust system / 25% nitro
For thrust: APC 6.5x3.7
19,460 / .28hp - 209w / 35.2oz - 2.2 lbs thrust / 68 mph pitch speed

For speed: 5.2x6N
19,380 rpm / .229hp - 171w / .82 lbs thrust / 110 mph pitch speed

Results show the TT GP-10 is the clear winner in max power (as a reference).
The engine is robust and may last longer than the other engines. If the wing loading is good for a
given plane project its a go with a .10. From there the engine can be swapped out for a more powerful
OS .11 or .12 even .15
Last edited by Amp Abuser; May 23, 2019 at 10:33 PM.
May 24, 2019, 05:09 AM
A man with too many toys
What about OS 10 FP vs OS 10 FSR?
Does the FSR have more power?

My airplane needs a 7x4 or 7x5 prop to fly well so all these high RPM numbers are not that useful from a practical standpoint.


I have an FP and wnat to know if a FSR will improve performance in the real world. Want engine in this weight range would have the best performance with a 7x5 prop (muffler installed)?


.
May 24, 2019, 06:53 AM
Registered User
surfer_kris's Avatar
The OS .10 FP is stronger than the .10 FSR, and the FP also vibrates less (the FP has an aluminum piston and the crank is identical between the two).

For the FSR I feel that a 7x4 was about maximum prop, but on the FP the APC 7x5 works very well. I just had to add one extra head shim.

The only issue that I have had with the FP is that it is ABN and the nickel layer will eventually wear off/flake away...

The FSR will do around 15300rpm on the APC 7x4 (using 10%nitro) while the FP will do around 15800rpm. Both with their respective stock mufflers. The muffler on the FP is a little quieter and gives a very good fuel draw at idel. Mine will idle down to about 3500rpm and one can even point the nose of the plane straight up at idle, without the engine stalling out.

Back to the original question, it is more about wing area and total weight of the plane than it is about HP numbers from a website converter using unknown propfactors. So the questions one should be looking at are wingloading (the WCL number), the style of the plane and the desired style of flying.

Any pictures of the plane in question?
Last edited by surfer_kris; May 24, 2019 at 07:35 AM.
May 26, 2019, 08:13 AM
Registered User
Thread OP
I'll try and get some pictures today . Thanks for the comments .
May 26, 2019, 11:02 AM
A man with too many toys
I was out flying my OS 10 FP with 7x5 prop this morning (15% fuel). It does have excellent performance with that prop. I doubt that the Norvel .074 can come close to turning that prop anywhere close to the same RPM (about 14,500 with a slightly rich flight setting).
May 26, 2019, 12:44 PM
A man with a plan
Balsaworkbench's Avatar
What plane were you flying today with the FP?
May 26, 2019, 12:52 PM
A man with too many toys
Quote:
Originally Posted by Balsaworkbench
What plane were you flying today with the FP?
It's my own design. 36" span, 280 sq", shoulder wing, no dihedral, no landing gear. When I have time in the winter I like to do at least one custom design a year. It came out slightly heavier than I planned but it flies well.

I may make some improvements and build a larger version next winter.

.
May 26, 2019, 12:57 PM
A man with a plan
Balsaworkbench's Avatar
Sounds like fun. What kind of airfoil does it have?
May 26, 2019, 01:18 PM
Registered User
surfer_kris's Avatar
Quote:
Originally Posted by RC Man
I was out flying my OS 10 FP with 7x5 prop this morning (15% fuel). It does have excellent performance with that prop. I doubt that the Norvel .074 can come close to turning that prop anywhere close to the same RPM (about 14,500 with a slightly rich flight setting).
Yes, that is a great prop on the FP engine, plenty of thrust and speed with a 5" pitch even at reduced throttle settings.

The Norvel will at most spin a 7x3 or the 6.3x4 prop (they are a similar load for the engine), nothing larger than that.

Below is a 34" wingspan (about 10% thick, nearly symmetric and "laminar flow" wing-profile) with the OS 10FP, flies great with an overall weight of around 22oz.
For sure a Norvel .074 could fly that too, but not nearly in the same way.
May 26, 2019, 03:17 PM
A man with too many toys
Quote:
Originally Posted by Balsaworkbench
Sounds like fun. What kind of airfoil does it have?
My favorite airfoil for small/medium sport planes is NACA2412. Zero degrees for wing, stab and engine. Keep the cg back to about 5% SM (or less) and a low wing loading. That makes a very fun airplane to fly.

.
May 26, 2019, 06:54 PM
Registered User
Thread OP
I bought this ARF kit several years ago and I am wanting to convert to glow.

This is the airplane that I have . I am not interested in a blazing top speed . I just want to run a
glow engine on the thing . I have an old O.S. fsr and a new in the box Cox Tee Dee .049 and I
have been interested in the Norvel engines for a long time . I have never owned one and I see
them for sale frequently . I haven't checked to see if they are still produced .

The electric motor and battery that came with this kit are heavier than a Norvel from
what I read about them . I will weigh them and compare the weights with the OS .10 . But
I really would like to try a Norvel . Thanks for the comments .

200 Kmh Electric Fiberglass Pylon Racer Hobbyking Speedflyer Swallow mit Gyro Kreisel *HD* (3 min 11 sec)


New rare Electric Fiberglass Pylon Racer Hobbyking Speedflyer Swallow mit Gyro Kreisel *HD* (6 min 43 sec)
May 26, 2019, 09:14 PM
//////////
coriolan's Avatar
What size is this plane?
May 26, 2019, 09:51 PM
Nitro Abuser
Amp Abuser's Avatar
https://hobbyking.com/en_us/electric...m-red-arf.html

Electric Fiberglass Pylon Racer 930mm / 36.6"

Will not fly very well at all with your new in the box TD .049
The Norvel .074 with a APC 6x4 or the 6x5 prop would be your
best bet for moderate speed with good thrust. Even still this is
not considered much engine with this size pylon plane. The RX
battery will need to be right under or behind the fuel tank in order
to balance the plane with a low weight Norvel .074

If I was trying to fly it a TD .09 would fit easy enough bit more power.
The plane would need the nose reinforced with a layer of fiberglass or
carbon on the inside back to the wing saddle. The firewall would have
some spruce square stock to give it some good grip and epoxy to set it
in place. 5mm thick ply plate, with epoxy brushed on the wood surface
to last from fuel exposure. The engine cut out done with care should
have a clean look when completed. Note a TD .09 with a 5.25 x 6.25
will bust 130 mph + can use a RC version or a throttle sleeve from a
Medallion engine.

Example of a TD.09 / 31.5" span
DART -TD .09 / APC 5.25x6.25E / 143 mph best pass (3 min 26 sec)
Last edited by Amp Abuser; May 26, 2019 at 10:31 PM.


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