Viking OS 49

Am I being led to believe that no one out there has ever used one of these engines????????????

I suspect the OS .49 in question is a big brother of the OS .40H series. Seems likely it's too big, too heavy and maybe even too much power, tho I can't believe I'm writing that. Pretty sure that D.Dirt flew his with a Fox .35. Steve

It doesn't look at all like a Super Cyclone. I didn't think it was to big as I saw Kaz using a ST 60 in a Humongous. Fairly similar sized planes aren't they?

>It doesn't look at all like a Super Cyclone. I didn't think it was
>too big as I saw Kaz using a ST 60 in a Humongous. Fairly similar
>sized planes aren't they?

The V60 is "medium-sized" for its displacement. If the OS 49 is basically the 50 in an earlier model, it is going to be both much bulkier and heavier than the 60's so loved by the east coast's Pattern Master fliers. The Humongous seems to come out lighter in weight, or just has more lift with its better airfoil, although the wing may also have more area. Versions of either one aren't too big for many 35's. The only one of either kind that I've seen fly often was relatively recently, Jim's Humongous with a Series 71 K&B 40 in it and it flew quite well with that. A Super Cyke would be really neat- looking (and period-correct) in any Humongous or Viking, however.

My own Viking will have a GH Torpedo 45 in it when it is finished. I've had one of the OS 50's. It was too big- looking for "my own Viking". My 50 had a physical appearance that was similar to the Max-H's, but it had a finned cylinder unit similar to a Max-III (although they are aluminum fins), instead of a drop-in sleeve the way the Max-H's do. I didn't consider it particularly powerful or speedy for its size, just big & heavy.

.
Kiwi

I never saw an OS Max 49 as a C/L motor. We did use them in R/C in the early 70's. They were nice runners but not the most potent engine on the block.
The only 50 that I ever remember OS making before the current helicopter version was the 50 FSR This was a dykes ring motor and was a really great runner as were all the FSR series. Again no C/L version that I remember but, there were several converted that I know of. They certainly were capable of flying any of the old larger models of the period. Parts are a little hard to get for this motor so you don't see it advertised for sale very much. Dennis

Bill,

Form your initial post refering to "Vintage" I am assuming you are refering to an OS spark ignition engine, is that correct? If this is so and you have an early OS sparker I think I'd find something else only because the engine is probably quite rare, at least here in the US. OS did make a repro of one of there sparkers 25-30 years ago, but I think it was a .35. Georgeous piece but I've never heard one run let alone seen one in use. I'm no expert on these engines, but OS has a history far preceeding the glow series.

Gents, for the record, OS has made model engines since the 1930's with many sparkies in its early lineup. Some were pretty original, but allot were at least influenced by American designs of the era.

I always thought that "vintage" refered to earlier glow engines and "antique" was the ignition engines?

The OS 49 is from the early to mid 1960's. Unless there was an earier OS 49, it is not OTS vintage. It is a single bearing engine. This was before the H series OS engines. It was used primarily as an RC engine. In fact, if memory serves, Jim Kirkland won the pattern event at the Nats with his Beachcomber with the OS 49 sometime around 1964. This airplane was published in MAN in the mid 60's.

I used an RC version in a CL scale Messerschmitt Bf 109G. It was a nice and smooth running engine. Unfortunately, it was destroyed, along with the airplane when trying a loop in the scale event at the 70 Nats. (That was an interesting day.)

I have another OS 49 that has been reworked by Tom Lay for CL. It has not been run. Looking at the Chinn articles from MAN, the OS 49 was probably not quite as powerfull as the ST 46 and the weight was comparable to the ST 46.

The successor of the OS 49 was the OS 50 which was still before their helicopter engine.

And after the OS 50, they came out with an OS 58. It has a BB in the rear and a needle bearing in the front. Looks like a Max-S 35 on steroids. Almost an once lighter than the ST 60. I'm flying one on a Fancher Immitation, but alas, it is no yet a stunt engine. The 2-4-2 break is not satisfactory although an extra head gasket helped. The timing is reasonable. Anybody got any ideas how to improve the 2-4 break and runaway?

Thankyou for all the responses! The engine in question is deffinitely not a sparkie. I have seen these engines for sale on EBAY many times. Some used and some NIB. The ones in box that were U/C said Stunt on the box. I have all 3 versions, 49 50 and 58. Just wanted to run something different from the usual engines normally seen. Interestingly enough when the 49 is in the plane it balances perfectly, no need for any nose weight added. I would think a 13" prop would be a good starting point?

>Thankyou for all the responses! The engine in question is
>deffinitely not a sparkie. I have seen these engines for
>sale on EBAY many times. Some used and some NIB. The ones in
>box that were U/C said Stunt on the box. I have all 3
>versions, 49 50 and 58. Just wanted to run something
>different from the usual engines normally seen.
>Interestingly enough when the 49 is in the plane it balances
>perfectly, no need for any nose weight added. I would think
>a 13" prop would be a good starting point?
>
>Bill

I'd be interested in knowing what "balances perfectly" means and your source of reference. My Zilch X is in many ways closely related to the Viking, and the former balances at 12 1/2%, a mere 1.5 inches back from LE. Chord is 12 inches.

Took an aluminum spinner and nearly two ounces of lead to move balance point forward to where I was happy; and it wasn't bad before throwing weight at it, 2003 NW Regionals, first place, OTS, in a squeaker over Mike Conner.

Dan, the reason that a Fox 35 isn't going in this plane is that I just don't like them. Only got 2 Fox engines that I like, the GMA 40 and the 59. The others just don;t appeal to me. Nothing wrong with them, just don't like them from the way they look. Doesn't make any s
sense I know. Just something for everybody when it comes to engines. Pretty much a fan of OS ST and ENYA engines.

Dan, am I correct in assuming that you live in the N'West? I used to live in Springfield Oregon many years ago and used to go the Regionals as well. Did most of my hobby related shopping at Eugene Toy and Hobby and at Elmers in Salem. What a gold mine of kits Elmers was! If EBAY had been around back when his kids were selling off the store stock they would be very rich by now to say the least! Bought a Sterling Skylark there for $20 bucks because the plans were missing! Never find a hobby store like that again. Bill

I agree with dirtydan about a good Fox 35 on the Viking. I built the Brodak Viking this summer and started out with a 40LA and it now has a modified 35FP which is still alot of power for the plane. I replaced alot of the kit would to make it light and I think it turned out too light. Mine doesn't handle the wind very well at all, but it's a ball to fly! The Brodak Viking has a stronger wing but the outside dimensions when compared to a set of old Viking plans is right on.

The OS 49 was short lived engine in the early 1960s. It was produced for five years and finally replaced with OS 50. The early RC pattern flyers were using the K&B GH 45 up till about 1960. Clarence Lee and the Veco line of 45s began to dominate and then specially prepared Veco 61s. God forbid the US flyers would use an engine marketed abroad. The early top RC pilots were a tight group. This engine may not produce a stunt 4-2-4 stunt run but may work very much like the Enya 35. I have one and had the same idea as many of the early engine designs were based on the same design concepts. Competition was the fuel for everything that took place in the late 50s and early 60s as proportional radios came onto the market. This was the era when CL began to take a back seat and domination of RC began. Jim J

Crash2Much,

Yes, I live in the Pacific NW. Bothell, bedroom community to Seattle.

Balance of a Viking at 2" from LE is fine. It's just that in a convoluted manner I got the advice from Bob Whitely to push the balance point forward to, among other things, get better line tension. Worked as advertised.

Dan,
How does more nose weight give you better line tension? I have to try it!

>Dan,
>How does more nose weight give you better line tension? I
>have to try it!

I know a trick question when I see it...

Nothing trick, just interested.

I'm going the same way, Super Cyke and Viking, maybe next winter.

Jim, thankyou for the first positive response to my selected engine! Bill

6 inches from the leading edge, I think I'll pass on that one. That flight report will have to come from someone else.

However, here's a pic of my Viking.

The first time I flew my Viking, it pulled like a 49 Buick and was just about as sluggish. I built the plane very light, 49 ounces ready to fly – see the photo. Besides the OK Super .60 and metal spinner, there is the usual assortment of spark goodies – three “AA” cells, coil, condenser, switch, etc. How much power does the OK make? It turns a Top-Flite wooden 12-8 at around 7,500 RPM.

Why so sluggish? Turns out, the balance point was just about on the lead edge! I started adding tail weight and got up to around two ounces and it became a superb flyer (AND, you were right, Dan), the pull was considerably less. It now balances around 2 inches back.

As I figure, since there was considerably more weight forward of the bellcrank mount (vertical pivot), centrifugal force made it yaw out - I seem to remember the inboard wheel being a bit forward of the outboard. Should account for some extra pull, right? When I fly it now, the pull is still adequate but the yaw, as seen by the wheels being more in line, is substantially less.

Read on – When trimming my Brodak Nobler, I had to add quite a bit of noseweight – nearly two ounces to make it fly stable. I could not believe how much more it pulled after that. The wheels seem aligned now but I can’t recall how they were before but line tension was very light.

Jim and Randy – The OK works extremely well in the Viking – I’m well over 300 flights and I clean the plug every 30 or so flights. I switched from alkaline to NiMH batteries and it reduced the weight by about 1.5 ounces. Runs about 8 flights on a charge. Notice the size of the tank. I run gasoline and castor – nothing else, and two ounce is good for around 7 minutes. The Super Cyke should also be an ideal choice.

By the way, we test flew John Brodak’s original kit Viking in October of 2002. John built it very light and it did well with a Fox .35.

Bob Z

I think you shoud go for it. If it weight to much you can machine a alum. bearing with a brass bushing,I have done this an it works good, you lose at least haft the weight of the bearing. You may have a great stunt engine . But on the other hand how come you don't use a V51 st the old bushed one just thinking that all. Good Luck

I flew an OS 49 in the mid 60's in a Shark 45. As someone noted it might not give a 4 2 4 break. My experience was that is true. The engine is not a powerhouse but was quite adequate in the Shark even at the 4300 ft elev of Salt Lake City. The engine was run with both open exhaust and with the OS Jetstream muffler. It was actually a fairly good combination in the Shark but just didn't have that Stunt Engine Sound but otherwise ran fairly well in a pretty constant speed fashion.
The engine did have some weak points. I had the big end of the rod give out at a contest in Denver once. Rusty Brown gave me a bad time about blowing up my stunt motor while none of the racing and combat flyers did. I replaced the rod at the contest with one taken from one that came from an engine someone had given me that had a broken crank. The crank disk had broken from the shaft due to a sharp undercut at the shaft to disk transition.
As I recall I ran it on a Top Flite 11x6 prop and it seemed quite happy with that. I think a 13" prop would really overload this engine. All in all an OK engine but surely not one of the greats. It would probably be more engine than needed in a Viking.