Ive been thinking a lot about how to mount a saito 100 into the nose of my topflite mustang. the only way to make it look scale is to mount the engine inverted.

If i mount the engine inverted, then, probably, the "valve-pushrods" will be the first thing to hit the ground when crashing?

How durable is the "valve-stuff" that is mounted on a four cycle engine? [sm=sunsmiley.gif]

The valve covers are pretty durable and can take quite an abuse if the plane noses over on the ground. In fact, I prefer the valve covers to hit the ground rather than the cowl. On the TF Mustang, if you crash and the cowl hits the ground first, then the cowl might get pushed back into the pushrod tubes and bend them if it's a hard enough impact.

Saito is a very durable motor. If you crash in soft dirt it should be no problem. If you hit a rock at 100 miles per hour, well nothing can withstand that kind of punshiment.

Build and fly and enjoy your Mustang. Don't look for a crash. You can always get replacment parts if the worst happens.

These pushrod tubes, do they make contact to the ground at all when crashing? or are they "protected" by the crankshaft and the valve covers when crashing in open terrain?

Im glad to here that they seem to be pretty durable after all. But if they break, the valves can go right throu the piston right?

On crashing, the lower front of the cowl and the valve covers will contact with the ground.

ok Richard, sounds good...Is a four cycle engine less durable then a two stroke engine?


haaha yeah why not

last season I lost the entire wing on my u can do .46 in flight about 100 feet up. (wing bolt plate came unglued...) anyway, the plane arced over and impacted nearly vertical, saito .72 first. There was absolutely no damage to the engine at all!!

I lost my H9 Corsair due to a mid air with a P-40, and my YS 110 four stroke plowed straight down into the ground from about 300 feet without any damage. In fact, that engine runs much better today after the crash.

hmmm sounds really great!!! I have always thought that fourcycle engines is much less durable then a two stroker, but im starting to change my mind.


IF it breaks, what "goes first" then? is it expensive to repair?

Blue Moon,
Dont think so much about crashing. Not good for the mind set <g>. Simple nose overs are no big deal. Like was said before, not many engines survive a rock or pavement impact. So some place in the middle you might ding a pushrod tube or scuff some finish up. But I sure wouldnt worry about. I have 3 saito 120s with an average of 80 hours on each and they run fine. I do suggest you adjust the rocker arms at the beginning of each flying season and after run oil if they're gonna sit for more than 4 or 5 months to protect the bearings. The idle on mine are so low that you wait for it to die, but it doesnt. And will throttle up with no problem or delay. Durability depends on care. They DO take a little more care but you'll be rewarded with a fine running engine. The most common failures that I've seen is broken rocker arms because they were never adjusted or rusty bearings because they sat for awhile and still had glow fuel in the engine. Repair expense is relative. I can get bearings local for less than $10 each. I think the last time I looked, a bearing set for a saito 120 at the LHS was around $25 or $30. Many guys in our club just repair them or have the local engine guru fix it. I've had some 2 strokes that didnt fair so well in crashes and you just chunk the engines cause the parts cost more than the engine is worth. I used to think the same way you are right now. Glad I switched to 4 strokes and even happier I started using gas.
Edwin