I have been flying my spitfire for 3 yrs now and the OS46 is tired. I was wondering what engine to buy for it , Its time for a change, what about the evolution engines or the super tigre in a 51 size? anyone have comments on the the two? Let me here the pro's and con's It's a kyosho spitfire with a 54" WS
Thanks

Go with the ST.51. No 109 can catch you. Just my opinion.
Edwin

I never owned a ST or an evolution what are the like ? I ran OS for a long time, but now I think it's time for a change!

Go with the ST 51. I had a ST 51 on a VMar P51 several years back and it was quite fast. Much faster than my Kyosho bf109 with an OS 46FX.

If you mount it inverted use an OS F plug. They are hotter and make for a more reliable idle and transition.

isnt the F plug a four stroke? and yes the engine will be mounted inverted! If ST is a good engine why such a big price differance between OS and YS or RCV.. I don't mind paying the extra money for quality and reliability but the differance is quite large...

Why are the STs so cheap? is that your question?

Didn't ST go out of business a few years ago and didn't they recently reappear as a Chinese based company?

You get what you pay for. YS is a high performance engine, and it will blow away both OS and RCV. However, just like a Ferrari, it's not for everybody. BTW, I'm using YS four stroke in almost all of my warbirds.

Check out my website to see and hear the spectacular performance from YS engines: [link]http://www.warbirdobsession.com/[/link]
Especially check out the Kyosho Zero and the Dymond Bearcat, both of which are similar in size and weight to your plane.

The ST .51 is an outstanding engine. All STs are great engines. HISTORY: When STs were distributed by World Engines (also the distributor of OS) they were the cream of the crop. ST engines were much more rugged than OS. OS was considered the newbie's plug and play toy. In 1985 Great Planes bought the import rights from John Maloney. OS received its fame as a out-of-the-box item while ST required some care as it just got better with age and use. The OS remained a favorite of the newbies coming into RC during those times, because they did not have to do much with them. We older more experienced modelers knew where the real man's machine was and ST was it.

When GP bought ST and moved the production to China from Italy there was a period when the ST was not available. Couple that with so many engines now on the market, and GP, IMO, simply has not been able to return ST to the unlearned market, thus the prices have tumbled. I LIKE THAT.

Once you get a few tanks of fuel through that .51, you will not want to trade it. Dependable. powerful and user friendly and I was flying a Profile thing with one just this day.

The OS F plugs are for 4 stroke motors but work great for 2 stroke motors that are mounted inverted. The F plug has a longer element that generates more heat which is needed for 4 strokes, but for inverted 2 stroke motors, the extra heat helps idling and transition since there is natually more fuel / oil gathering at the head.

Regarding price, OS and YS are made in Japan (higher cost) while ST are now built in China (lower cost). ST never went out of business. They were originally made in Italy and were around for a long time, but they moved operations to China a couple years ago. Probably to reduce cost and price to improve competitiveness. During the transition, it was hard to find some of the ST motor sizes especially the 51, since it was so popular before.

Give the ST 51 a try. I think Tower Hobbies has some discounts if ordered before the end of this year.

I've been using a tower hobbies .46 for about 2 years now and it has been 100% reliable. It is also a real power house compared to a lot of others out there, comparable to the O.S. FX series in power. Its also dirt cheap so I dont think you can beat it for the bang for the buck factor. Anyways, just something to consider.

P47 thunderbolt
You just sold me on the ST 51. I'll give it a try, Thank you all for the input...
Greg