ORIGINAL: k1s1h1
I am going to get the space walker II from horizon but I think I want to get a four stroke. The specs call for a 41 size 2 stroke and a 40-82 4 stroke. It seems like a large range on the 4 stroke. This is my second plane and i don't want to much engine then i can handle. What would be a good 4 stroke. And what are the advantages of a 4 stroke over a 2 stroke.
I suggest the Saito 72. It is an excellent, troublefree, reliable engine. As with ANY 4 stroke, I STRONGLY recommend using a tachometer along with the manufacturer's breakin directions for a trouble free engine.
The 72 is a little over powered for the plane, however, that is why there is a throttle control. As long as you are not flying wide open (unless your skill level is up there ) you will have no problems.
4 strokes have been getting better in performance. A 72 will provide equivelant performance to a hot 46 or an average 61 2 stroke.
4 strokes are more fuel efficient than a 2 stroke. The size tank you can fly a 46 2 stroke on for 10 minutes, will normally fly a 72 4 stroke for 15 minutes or longer.
4 strokes have a more "realistic" sound than a 2 stroke, and while the db level of the exhaust may be the same as a 2 stroke, the 4 stroke is perceived (heard ) as being quieter because the exhaust is at a different pitch.
4 strokes NORMALLY are run about 9,500 - 10,000 rpm, while 2 strokes are NORMALLY run at rpms much higher. Because 4 strokes have a lot of torque, they can use larger props. While a 2 stroke prop is just "whipping up" the air, the 4 stroke is actually making use of the air. A prime example - a 46 2 stroke will run an 11x7 @ 12,000 rpm for a given speed, a 72 4 stroke will run a 13x6 @ 9,500 rpm for the same or slightly higher speed.
Hope this helps.