mRqS

Hi ,

I want to buy a new 4-stroke engine for my next project:
1:6 scale Bristol F2b from www.flairproducts.co.uk

As I saw on www.osengines.com a OS Max FS .91 surpass II (without pump) can turn a 16x6 prop, while in Magnum XL .91FS manual I see "only" 14x6.
Is an OS really much more powerful or I can use 16x6 with Magnum as well?


thanks in advance for answers

greetings

mRqS
http://rc.marekszulen.net

coomarlin

My Feedback: (1)

Once again a perfect example of a company making exagerated claims. I don't think there are too many people with 91 surpasses that are turning a 16x6. I think the 14x6 that the magnum quotes is much more realistic. I have a Saito 100 which is a more powerful engine than a 91 surpass and I turn 15x6 and 16x4w props. I'd like to see rpm numbers of a surpass turning a 16x6 prop. I'm sure they are not impressive.

The OS will have a slight advantage in power over the magnum, but both are good engines. If you are looking for more power go with a saito 100, it's lighter than both the mag and os 91's.

91zulu

My Feedback: (2)

The os has more power, but cost more. a lot more. A better engine would be the TT 91 it cost less. but has more power that both of them.

OS-$229
Mag-$189
TT- $179 at tower

Gry101

My Feedback: (8)

I have two OS91FSIIs and tried a MA 16X6 and got only 7800 RPM. Way too low for this engine. Try for around 9500. I have an APC 15x4W at 9700.

Andrew

mRqS

Hi Friends!

Thanks for answers.
I don't know a TT engines.
Probably I'll buy a Magnum.

btw, What about a quality of Magnum 4-stroke vs OS?
I've Magnum 2 stroke XL.61 in my Extra 300s and it's a great engine.

greetings

mRqS
http://rc.marekszulen.net

Sport_Pilot

TT = Thunder Tiger

http://www.acehobby.com/acehobby/pro...ies/index.html

w8ye

My Feedback: (16)

Magnum, ASP, SC, & SY = the same engine. Try www.justengines.unseen.org in England.

My XL 91 FS turns a 14-8 at the same rpm that my Surpass I turns a 14-6. I would have to assume that the Surpass II would be about as good as the newer Magnum style engine.

Jim

edge 3644

Mrqs,
Thunder Tugre 91fs is a very good engine. You can expect over 10k revs on 10-15% fuel and APC14X6 prop, what is better than OS or Saito same size.
Needs longer break in and is 2oz heavier than OS, but I do not think it really metters.
powodzenia
Robert

Flyboy Dave

My Feedback: (21)

I run the OS, and the Magnum .91's. For all practical
purposes....you cannot tell them apart. One tankfull
on the ground, and they are ready for flight. I run them
on smaller props....12-9's, at 9500 static....on 15%.

The Magnum at the usual sale price of $150. is the best
buy, and most user friendly of the lot. I have the YS .91's,
and have had the Saito. For me it's the Magnum for sport,
the YS for performance. The middle of the road (other)
.91's don't have much advantages to offer, except higher
price. As always....your mileage may vary.

Dave. [sm=biggrin.gif]

IronCross

I have never had an OS fs but I do have a couple of the Magnum .91 fs engines. They are sweet running engines. I was a little hesitant at first to buy them but the on sale price drew me in and I have never looked back. I have several gallons of fuel through them now and have yet to have a dead stick. Great engines

Gone to a Higher Plane

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