MK-Aurora & OS 61 RF "Hanno Special"

Ha Bas,

Ja, de Mach 1 is inderdaad een snelle jongen. Je kunt er echter ook heel goed langzaam mee vliegen, dat vraagt wel wat behendigheid. En je moet geen langzame bochten gaan vliegen, dan valt hij als een steen uit de lucht !
Rechtuit vliegend voor de landing kan de Mach 1 sterk achterover hangend landen. Dat is wel een apart gezicht, "vroeger" heb ik dat nooit gezien bij Mach 1 vliegers.

Is het de Sultan die ik wel eens in een ander bouwdraadje van jou voorbij heb zien komen op een foto ?
Ben benieuwd hoe de Sultan bevalt. Zal ongetwijfeld fijn vliegen, doen vrijwel al dat soort modellen, mits ze niet te zwaar zijn.

Grt,

Arnoud.
 
A .61 engine. Alway's!

Trying to restore one. Bearing house is quite fragile and breaks easily on the lugs.
Later ones are improved on those spots. But became a different motor...

The holder of the carb is vulnerable too. It was made as light as possible.
So the front housing is very thin and short.
Even the crank was made light and could breathe very well...
Front bearing is an easy one, rear a special nasty size.
The motor is true ABC.

The predecessor had almost the same shape. Rounded head. But
measurements... very different. I learned. And parts not interchangable.
So... much different on sizes but looked similar.
Had ABC, but with a ringed piston. Had a smaller diameter crank to carb inlet
due to smaller diameter of de axe.

To mount the resonator, this ST had a special bracket/connector.
Making the construction stiff from front to end... instead of a silicon tube connector...

Motor is early '80ties... Was flown shortly by Prettner, but the motor could not keep up
in the type of flying Hanno needed to winning competition.
OS made him a deal an a dream budget to conquer the world.
Super Tigre could not offer, the power needed, nor the financial support...
lost on it and the race in sales, battle for the customer.
And became forgotten...

I expect the motor to run well when set in tune with a nice and correct set pipe.
And for a nice day's fly in a classic?
It needs 5% nitro... not a drop more...


The brittle casing... this engine has zero hours... hangar rash...
Was mounted and failed... and put aside...

IMG_3236.jpg


X61_RE_TST_1981_World_Champion_Hanno_Prettner.jpg
 
Laatst bewerkt:
if you need good bearings tell me i convinced big brand to produce hybrid bearings for engines, and it works like a charm. for fuel, 5% is indeed the best, with some klotz oil.
if i decide to sell, where is the best place to put the announce is it here or other good forums? trying to avoid scammers and such..
 
Original bearing of ST are more than good.
Italians used to make better ones than SKF!
Italians know how to cast aluminium. Most car carburetors came from Italy. Solex and Weber. :)
Marelli...
But ST made it to it's limits. So no nose overs!

Motor is fine, but the fixed exhaust port makes it less versatile
The header/collector is the problem.
The engine looks nice and tidy... probably a boxed life... and is there for nice!!!

Hmmm Klotz... alway's rust...
Airosave is gone... perfect brand of oil.
Now on Prosynth 2000 of Weston UK
Seems very good oil :) Motors look and stay sound with it...

Where to post, and what to ask? Wild guess....

You can post here on MBF and post on RC-Network.
And on Marktplaats and the Belgian 2dehands.be (same owner... eBay)
Here on MBF you need to put asking price.

See them go for as low as 80,- and higher...
Cost on eBay can be higher... way more charges and loads of crappy restrictions.
It has become a bore...

And parts for it? Impossible. Nothing left out there :(
 
Laatst bewerkt:
thanks. belgium 2dehands has not the right public i think, the motor has to come to hands of someone who understand.
is there a forum here of "for sale?
 
Strangely the head is mounted wrong.
It has been loosened for inspection.
It won't damage. Motors can be inspected.
But you need to be very careful and a 100% good fit with a screwdriver.
The fins are quickly broken. Bolts always to tight... and then... things go wrong...

Look at my photo how it should fit...
 
Saw your price. To high estimated... OS whould make that.
ST not...
Expect 125,- around. Then you are a happy man...
 
It is just what I learned... all those times.
If you are sympathetic to it, just keep it.

If top end... box must be pristine and unused.
All papers and stickers, as factory new even a original receipt will improve on it...
Those are true rarities.

A good Webra 61 RE wil set you back between 100 and 200 euro.
Friend bought recently one NIB for around 100 euro and now flies it on his Arrow RC1.
Motor is a true known powerhouse. It humbles an ST!
He build an e-version of that plane, with same wing... noticed that is even super fast...
humbling the Webra. Now his Scorpion powerd Arrow has the freference...

Rear exhaust... actualy the rear exhaust setup hinders the flush of fuel in the motor,
because it is more hindered by the balancing weight.
And must be compensated to get it even the same power as an side exaust.
The sole advantage of the rear exhaust is the possible streamline.

It is not about ultimate speed, but about constant speeds. The motor is not a pylon engine.
But more of a tractor peddeling though the exact paterns to be flown.

If you want speed, and want that lasting.. a simple low bucks ASP 61 will do best.
And many seasons. Does a better performance than any OS Prettner.
As I tested. Never expected so much incredible power...


Only with OS you are able to hit the jackpot when complete and new in box.
Those are now sought after exotics and gems. But the ABN cilider sets are brittle.

Even knowing that... The Pumped RF, and side exhaust and ringed can go up to to 350,-

A Prettner RF with the RE exaust, production numbers stamped on it,
and special porting to raise the required torq at low rpm... those hit the + 450 mark at asking price.
Deals are often lower. That jewel feeds the brain of many collectors.
A Prettner will perform on 10.000 rpm and with a prop 11 x 10
And +9.000 rpm with a 12 x 10. Exact data are on the net...
All tools for a constant flight speed, low noise level, zero nitro FAI fuels,
and compete with other talents of flying perfection :)
That all in the league of a thick PR sauce.
A small band-width to work with. And interesting to read and learn about.

Naturally I'd like you to see it go for that price.. but is not very realistic? Very sorry.
The ST is nice, but is what it is. Does not fall apart and is made in Italy.
So is my car... and that sounds good :) Stays put and make all the right noises.
 
Laatst bewerkt:
i have some engines which at the moment dont have a plane. but i might take it back from sale, we will see.
do you know who might have RC1 models for sale? looking for something interesting, e.g Aurora, Arrow, Magic..
 
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