I'm ready to move to my second plane and need an engine for it. I have been flying a Sig LT-40 with an OS .46 engine and haven't had any problems with it. My second plane is a Sig 4* 60 and I have to choose an engine for it. I was thinking about putting the OS AX75 in it and was advised that due to our altitude here (~5,000 ft) that a 75 would be preferable to a 61 for the plane.

My question is: How much better is an OS engine versus the others? I can get a Tower 75 for $100 less than the OS and it seems that all the OS engines in this 61-75 range are $50-100 more than their competitors. I'm having trouble justifying putting a $200 engine in a $95 airplane. On the other hand, nothing frustrates me more than an engine that's unreliable and consumes all my flying time messing with it (not to mention the fun of poor flight performance and dead-stick landings).

What say you?

If it makes you feel any better you'll put $150 (at least) worth of radio gear in the plane too.

I feel like the extra money is worth it. Take care of the OS you'll have it for a very long time. It'll go through two or three planes easy. Looking at the OS75 on Tower Hobbies you can get a 91FX for a few bucks more (Nice engine.) It's over kill for the 4*60 but might be more versatile if you plan to build something a little bigger in the future.

I have an OS 46SF that's well over 10 years old and still runs strong.

Hi Carson doc
A lesson i learned a long time ago is You only get what you pay for Seriously you wont get any better than OS I have been using them for years ,both 2str and 4str and havent had a bad one yet The quality of OS is IMHO can't be beaten
All the best
Styk

I see guys every weekend fighting bad engines. They have starting troubles, dead sticks, poor idle, lousy transition and so on. Sure, a lot of it is in the tuning but a good quality engine just makes life easier. All of my OS engines start right up, idle perfect and transition well. When you do have to play with the mixture, it's usually straight forward. This is just my opinion but I've found that the OS 2-strokes are the best all around engine for a balance performance, ease of use and reliability.

Never skimp on the engines ! Cheap is expensive ! OS and Saito are all you need.

If you really want great quality, look at Jett engines. Sure they're pricey but if run correctly and maintained properly, they'll outlast the best OS by far.

[link=http://www.jettengineering.com]www.jettengineering.com[/link]

For a general sport flyer on a budget I dont think the Jett engine is a good fit for a 4*60.

I see most engine problems have more to do with operator error than the engine. I fly almost all super tigre, tt, and magnum engines (budget engines) and dont have any problems. In fact I cant even remember the last time I had a dead stick. There are other folks in my club flying OS and they are always having problems. Its not the engine.

As far as lifespan that also has a lot to do with the operator. If the engine is run lean and not taken care of it wont last long. Even economical sport engines have an incredible life span. A friend of mine has a .60 bushing 2 stroke that is 15+ years old and has hundreds and hundreds, if not thousands of flights. It still runs like a champ.

OS's are nice engines but overpriced. Look at the ST 75 or 90 or the magnum 90. Those are great engines at a good price. Also lots of folks here sing the praises of the tower 75.

On a side note, the actual model is the cheapest part of the plane. On a warbird kit I just bought I think I will end up paying 4X-5X for the radio, retracts, engine and other accessories as I paid for the kit.

Also, dont even consider buying a 60 sized engine. You will find that .75-.90 sized engines weigh the same but you have the advantage of more power.

I have to agree wit GRINGO Flyer here.

In my shop I have many types of engines Webra, Thunder Tiger, Super Tiger, and yes OS. IF you take care of the engine it will last 10 -20 years.

The key to happy engines is knowing how to tune them, use the right fuel and don't try to get 20,000 rpm out of an engine designed to run at 13,000 rpm. BTW - I also beleive in Caster Oil vs Synthetic oil.

IMHO it has a much better ability to lubricate and dissipate heat.

If you get a GOOD Tower engine they are great. However MANY Tower engines are plagued by air leaks and transition problems (and some also have faulty carbs ). Do a search here on Tower engines and form your own opinion. As for me, I have owned 2 of them and will never own a 3rd one.

I had a couple of the 46's and wouldnt buy another one. Neither one ran right. I have never owned a 75 but I havent seen the complaints on it like the 46.

If you dont want to go tower you can buy super tigre or magnum and still save some green over the OS.

I've become a pretty big fan of Super Tigre over the past couple of years. It's true that they need a little more attention to the set up than an OS but once set and broken in, mine have been a pleasure to fly. At first I was really frustrated with them but that only highlighted that I had alot more to learn about the tuning process. It's made me a better "mechanic" when it comes to the engines - and that's a good thing. I have some OS engines I run as well and they are great performers but I really wish they weren't so much more cash. If cash wasn't a concern I'd probably go with the OS in all honesty but don't let the lower dollar amount of Tigres fool you. If I was having deadsticks and other issues all the time, they would be out the door. Looking forward to firing up my new ST 75 in my King Kobra.

Dan

To each his own with engines. I really like OS engines. But, I own two GMS .47s and I have no compliants; a ST .61 ringed; OS .10LA; OS .25LA; the list goes on. I am at 800ft above sea level though.

In practical theory, if you use less nitro content fuel at higher altiudes your results may be better. Due to the leaner air less nitro may be needed. Just imagine having a container filled with a combustable liquid, if there isn't any oxygen in the atmosphere it will not ignite, unless of course, there are enough oxygen atoms in the said combustable liquids composition.

A guy I met here in Indiana flies helis goes around the U.S. for shows, Lou (his name) told me that he has no problems with engine performance when he adjust for the nitro content at different altitudes. I have never been able test this out though.

For my money, I'd go for a Magnum/ASP. From my experience their 4 strokes are great engines and great value, but I don't use 2 strokes so can't advise you on that. I do have a friend who tested a number off ASP's for an importer here, and he said the .61 was as good an engine as he's ever tested.

Put this on the For What It's Worth file, I've got OS's, Saitos, SuperTigres, gassers and Magnum engines. I've seen any of the above run great and I've seen them not even able to get off the ground. ANY manufacturer can have a bad engine but there's so much to tuning that makes an engine good or bad that it's almost personal as to whether an engine will be good or bad. I would say to take a look around as to what everyone at your field is flying and THAT would be the best spent money. They know how to tune them, repair them and maintain them. Your knowledge base is already expanded by their knowledge and support. IF you are the type of person that likes to take the road less traveled, you can step out but remember, you're on your own so listen to everyone but make up your own mind based on what YOU think/know is correct. I figured out early on that EVERYONE has an opinion and they're willing to share it, just remember, they don't have to live with the results of what they suggest.

For what it's worth, most of the older guys in my club use OS 2-strokes or Saito 4-strokes. The younger (or younger in the hobby anyhow) guys have a mixed bag of engines.

I have a SuperTigre G-75 in my 4*60 and it has been an excellent engine. As already mentioned, initial set-up and run-in were more involved than some other engines, but now that it is thoroughly broken in it starts beautifully, transitions smoothly and idles at 2000 rpm or less. I ran it with a 13x6 prop for a while, but it gives better power with a 12x7 or 12x8.

When it comes to engines, the money is spent for nickel. The higher the nickel content, the better the engine. They are all pretty much CNC machined nowadays and all have great tolerances. The price difference is for the nickel. OS Max might cost more, but offer years and years of reliable power and they have great customer support. My OS Max engines all start easily, run strong, and require the slightest adjustment only when the seasons change. I wouldn't even consider running anything else.

Do you mean the nickle content of the aluminum alloy engine case, or do you mean having a nickle liner on the piston sleeve? If you mean the sleeve, I've got news for ya'. Nickle plating isn't worth a dang in such an application, it's crome alloy that you want in there not nickle.
I cannot tell you how many times, and engines, that I have seen that are not too used that have the nickle flaking off - this is really bad news and will destroy the engine on all levels.
The 'cheapo' (Chinese made) engines I have actually have been better performers than some of the higher end engines (Japan production).
Perhaps I am bised since GMS.47s only cost me 50 bucks; ST .61 Ringed 55 bucks from a local friend. Even if I had to pay the marjed down retail it would still be worth it to me.