djlyon

Sell an engine!!!!!!!!!!!!!!!!!!! That would be like selling a child!!!!!!!!!!! I ahve been known to give 1 or 2 to a good home though.

Denis

NikolayTT

Dear Fellows,

Thank you very much for the advices !!!
It seems the "way to Webra" is very attractive and will consider to sale
at good price some of the best OS.91 I have in order to move to the
Webra-world as soon as possible. eBay is working just for this
and fine for me, at least so far.

As for the castor oil I support Jan's statement only within the limits of
Scandinavia where in most of the time the weather is too cool for
the castor. Still the best results on OS.91 I have got with with 12%
nitro, 6% Castor and 14% Aerosave(Graupner synth.) oil. After
4-5 gallons of fuel like that the rpms are almost the same as for
new engine.

Regards,
Nikolay

NikolayTT

Sell an engine!!!!!!!!!!!!!!!!!!! That would be like selling a child!!!!!!!!!!! I ahve been known to give 1 or 2 to a good home though.

Denis



Denis, you are unfortunately right and now I feel even guilty to sale anything ...
But maybe I will consider presenting giving the engine with the "toys"
around (plane and servos) to some one who will care about and fly it nicely.
There are so many nice young fellows who suffer like hell from low cost
engines; I feel sorry for them and I still remember those years on my own.
That would give me more plesure than the money can buy; do you agree ??

Nikolay

Steelie

My Feedback: (18)

Hobbsy,
I have two of these older Webra .91 Speed engines. I have yet to use either. I need a muffler solution and I see the ST on yours. How well does this setup work? RPM on the ground/prop? I have the Dynamix on both. After reading all the stuff on the Dynamix, maybe just leave the OS 7D carb off and go with it. I may use one in a AKM Models Su-27 if it will perform as needed. Let me know what you think. Tuned pipe recommendations will also be helpful. Glad to read less nitro is good too.


Thanks, steelie211 Dan

Steelie

My Feedback: (18)

I so agree here. I have more than.......where did this guilt feeling come from just now. I love my engines....and I DID feed the cat last week.

I see the prop/RPM...just didn't read far enough. I wonder if a 13 x ? or even 12 x ? would be too light for this beast.

steelie

Hobbsy

My Feedback: (102)

Dan, putting a Fox .74 muffler on them is much easier than the SuperTigre, you have to cut the bevel down around the ST stack at the phlange and drill new hole in the phlange inboard of the existing ones. If using the Fox .74 muffler you can simply use the Fox as a pattern and drill and tap the engine for 6-32x5/8ths socket head screws, there is plenty of meat there to do it. If you wanted more squeezing power you could use M4 bolts which have finer threads. I don't fool with tuned pipes anymore, if one of yours is an ABN engine it would respond to a pipe from what I understand. Any of them will turn a 14x6 APC about 10,000 to 10,500 rpm on 5% nitro. They hammer pretty good if you try to go over 5% nitro.

Dr1Driver

Those Webras will handle a 14" prop easily. Whatever muffler you decide on, be sure the outlet is fairly large. Webras like to breathe. Keep the Dynamix carbs and find someone who REALLY knows how to tune them. The power will be awesome.

Dr.1

Hobbsy

My Feedback: (102)

Dan, here is where you can read about the carb setups, just scroll down to the DynaMix.

http://www.webra-austria.at/download/motor_e.pdf

SuperViking

My Feedback: (4)

I had a webra 91 old style, it had a pitts muffler from bisson on a Dalotel from zimpro, all I heard was bad things about the Webra 91 until I tried for myself, Mine would eat an O.S. 91 Fx alive with more prop, APC 14x8 at 9,900 0n the ground using TNII carb with perry pump. on 15% morgans with 4OZ of castor added, the O.S. was 9000 with same setup, no pump. The webra would not run good without pump. It was somthing to hear that thing unload out of a split s on the dalotel. later I piped both engines and the webra was scary strong compared to the OS. Been flying webra 2 strokes ever since.

DarZeelon

Quote:

ORIGINAL: Dr1Driver

...It likes nitro. It occasionally kicks-back when starting, due to the high compression.

Dr1,


That part of your statement is a bit contradictory...

I agree with Dave Hobbs... This engine is not particularly a nitro-lover...
The kick-back is one of the symptoms.

Dr1Driver

I've had two Webra Speed .32s that would eat an OS .32 for breakfast. Both would tach the same on the ground, but you could hear the Webra unload at least another 1K RPM in the air. Flight performance proved it, too.

Webra - Quality, Reliability, Power - what else do you need?

Dr.1

lhughes33901

My Feedback: (1)

I have a webra .91 and I was wanting some opinions on running Cool Power 15% nitro fuel?

Hobbsy

My Feedback: (102)

It will run like crap and you'll blame the engine when you should be blaming the fuel. On 5% fuel with 20% castor that engine will last till your Grandson wears it out.

djlyon

Well then let me say this about that. Hobbsy is exactly right.

Denis

lhughes33901

My Feedback: (1)

Ok then. that answers that, I have some omega 10% I will give a try. How about a 15x6 prop, I am going for a flatter prop.....

DarZeelon

Mr Hughes,


After two prominent contributors give you the best advice; to use 20% castor oil and 5% nitro, you try to 'compromise with them' by going half way?

Just get some real FAI fuel (no matter from whom), which is 20/80 degummed castor/methanol and add 5% nitro to it.


It may even cost you less than Omega™.


This engine will not like 10% nitro very much...

lhughes33901

My Feedback: (1)

Fair enough, just was wanting to keep everything on the same fuel, but I guess it all can run on FAI fuels right?

DarZeelon

Mr Hughes,


Wanting to run all your glow engines on the same fuel, is akin to running your Chevy family 'beater', your Lamorghini Diabolo and your Ford PowerStroke™ Diesel truck on the same fuel...

Engines are never 'one size fits all'. Model engines cannot compromise with you.
Each needs at least a certain fuel specification.

Some may run better on a certain fuel, while other engines will not tolerate it...


FAI fuel with 5% nitro added will run very well in all your normal two-stroke engines.

Your YS four-stroke, on the other hand, will just puke on it... 20/20 synthetic is very good for it.


...Just a couple of examples...

lhughes33901

My Feedback: (1)

Well with that, I am more interested in what prop to run, I am wanting to run a flatter prop so will a 14x4 be ok? or should I run a 15x4?

DarZeelon

Mr Hughes,


The 14x4 will be too small a load on that high torque Webra.

I believe Webra recommended a 14x6 as a minimum, for this engine at that time.


A 15x4 is the bare minimum.

And... you might encounter some overheating, if hovering is your favorite mode of "flight"...


I have seen it happen with some other .91s.



This engine was designed for flying at speed, when planes were actually being flown; not hovered...
Hovering is for helicopters, which have engines with a special cooling head to keep them at proper operating temperature, with the reduced airflow.

Real planes; including those that can 'hover'; like the Edge 540, Extra, Cap... all have prop pitches that are at minimum ~65% of the diameter...
That would translate to a 13x8 prop on your Webra, which will actually fly the plane nicely too...

lhughes33901

My Feedback: (1)

Ok, I have gone with 5% fuel and a 14x6 prop on the webra that is on a pheonix models extra 330s... No to see how it will fly....