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Old Mar 09, 2013, 07:57 PM
Bill Mohrbacher, MECA Fox Guy
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Beaver Falls, PA
Joined Dec 2006
656 Posts
NVA for Webra 1.7

Today over at the Lebanon, PA swap meet I picked up a sweet little Webra 1.7 cc glow engine. I need the correct needle valve assembly for it. Any one have one? Is the NVA it uses the same as any other Webra NVA?
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Old Mar 09, 2013, 08:21 PM
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Hartsville, SC
Joined Apr 2006
859 Posts
Quote:
Originally Posted by Twin Stack View Post
Today's Mystery Engine is in the nose of this great looking model

"Stunt Rocket"
American Classic Stunt and Sport Model
The Stunt Rocket was designed by Walter Musciano in 1951 and is considered among the all time classic models. This stunning design features a 54" wing span and is powered by a .35 to .60 size engine. Our kit is laser cut, uses all modern hardware, and contains full size plans. This is one of the prettiest models ever designed by Walt Musciano.
KIT NUMBER: Black Hawk AC 1800
WING SPAN: 54"
ENGINE: .35 TO .60 (Modern .40 recommended)
SKILL LEVEL: Medium
Kit includes:
Laser cut parts
Built-up wing and fuselage
Full size plans
Complete hardware package
Atwood Triumph .49 with OS 703 muffler.
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Old Mar 09, 2013, 08:52 PM
I don't want to "Switch Now"
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Toronto (Don Mills), Canada
Joined Dec 2002
16,709 Posts
I spent some time today getting this old Atwood .049 to run.
Pretty sure this was in fact the motor that would only go "pop - pop -pop", not the OK Cub I mentioned a few days ago.

Initially that was all I could get it to do, bounce back and forth popping.
It had a few problems that caused this:

- Compression is not great
- It was sort of tight for the top half of the stroke, either varnish or perhaps a tiny bit of distortion in the liner. Not so bad that a bit of running would not loosen it up.
But the motor refused to run.
- Biggest problem I think was that the top end of the rod was pretty sloppy. At the bottom of the stoke the piston was up a bit higher than it should have been.
Because of the annular intake port that has a very short open period the piston hanging up was pretty much preventing anything from getting by.
This was confirmed by blowing in the back of the case at BDC. Unless the piston was forced down it was pretty much air tight! No way would it ever run.

The rod is held in with a sort of snap ring, so no way to reset it.

What I did was make up a 0.015" shim to push up the whole liner. I would have used .0.010", but 0.015 shim stock is all I have on hand. You can just see the shim in the first picture.
There were 4 head shims in it, so I took out all but one to try to keep the compression ratio up a bit.

After quite a bit of flipping, more nitro, some 3 in 1 to give it a bit more compression (and a nasty cut from theTE of an APC prop ) it started to run off the prime
Changed out the APC for a safer Tornado , a bit more fiddling with the needle, and it runs

Starting is now about typical for a worn out .049 - prime has to be just right and it takes a pretty good flip to get it going. But from cold it only takes a few seconds.

I have been running it on the 15% Nitro 29% castor fuel i usually run in my Fox 35.
If it won't start, then a couple of drops of 3in1 in the intake helps.

Second picture is of it running, note the slight blur of the prop and all the oil drops in the air Now that it has been run a bit there is no more tightness.
Compression is still pretty bad though

Unlike the OK Cub I posted earlier, I have absolutely no idea where or when i got this motor. I know I didn't buy it, must have been given it at some point.

Pat MacKenzie
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Old Mar 09, 2013, 10:25 PM
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A seller on you-know-where at the moment is getting a bit confused over which model ball bearing Enya he has (he has both of them listed in the wrong box), so below we show the differences. The first 2 photo's on the top row show the earlier Model 5224 Enya 35-III Special. There was no 35-IV, so the later (and last) 35 Ball Bearing became the Model 5225 Enya 35-V BB. Note that the V has a round venturi, "bumps" at the back of the case and has a different shape of prop drive (with a smaller front race). Also, the 35-V has a taller head and an exhaust divider
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Old Mar 09, 2013, 11:42 PM
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Originally Posted by N99JH View Post
Atwood Triumph .49 with OS 703 muffler.
The exhaust is on the wrong side...........
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Old Mar 10, 2013, 12:32 AM
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Belgium
Joined Aug 2004
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A Super Cyclone with an OS exhaust ?
A Bullet glow ?
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Old Mar 10, 2013, 03:22 AM
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Engine Old - dell' Ing. Augusto Serafini ( Bologna ) Italy (3 min 2 sec)
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Old Mar 10, 2013, 03:32 AM
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Danny, how much are these things worth ?
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Old Mar 10, 2013, 03:47 AM
Electrif(r)ied nitroman
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BelgiŽ, Vlaams Gewest, Putte
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Originally Posted by Twin Stack View Post
Danny, how much are these things worth ?
Hi Bob,
Try to answer that the politicians way. They are shure worth something, the value of these engines will be set as soon as someone is offering one for sale and how badly some one want's it.
But, most important You will have to find one first and that calculates in value.

Regards,
Danny.
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Old Mar 10, 2013, 03:49 AM
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http://www.old-engine-model.com/en/k269.zhavici-motory/

Year: 1959
Manufacturer: MVVS Brno
Size: 26
Only 16 examples produced
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Old Mar 10, 2013, 03:52 AM
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Quote:
Originally Posted by danny.act View Post
Hi Bob,
Try to answer that the politicians way. They are shure worth something, the value of these engines will be set as soon as someone is offering one for sale and how badly some one want's it.
But, most important You will have to find one first and that calculates in value.

Regards,
Danny.
Hmm, so we're talking at least US$5000 here Danny ?
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Old Mar 10, 2013, 04:02 AM
Electrif(r)ied nitroman
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Originally Posted by Twin Stack View Post
Hmm, so we're talking at least US$5000 here Danny ?
Looks like an optimistic price tag, but if that's what someone is prepared to pay for, then the value is probably set.
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Old Mar 10, 2013, 04:03 AM
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Belgium
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Originally Posted by Twin Stack View Post
Hmm, so we're talking at least US$5000 here Danny ?
LOL I have been trying for years to buy back the one I sold to him years ago.
It was a different one from the one shown. Unless he's sold it already ?
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Old Mar 10, 2013, 04:04 AM
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Belgium
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Originally Posted by danny.act View Post
Looks like an optimistic price tag, but if that's what someone is prepared to pay for, then the value is probably set.
Optimistic ?
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Old Mar 10, 2013, 04:12 AM
Electrif(r)ied nitroman
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Originally Posted by Reginald View Post
LOL I have been trying for years to buy back the one I sold to him years ago.
It was a different one from the one shown. Unless he's sold it already ?
No, not sold it, it's still in my collection. There's not enough space left on Your engine shelf's to find a place for the Garbo. However, as already told, You will be the first to know if it's for sale.
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