RE: What Am I Missing Here?????
 

I have a new Tower Hobbies .75 abc that is really tight and will get the heat gun treatment for the first firing. And yes, I have broke a few car engines in with a prop (it is preferred but depends on crankshaft type sg or std threaded):D. It doesn't matter if it is a car, boat, or plane engine. A tight ABC engine is a tight ABC engine.:D The point I was trying to get across is that I preheat the clyinder, and then run them at a couple clicks rich at a normal operating temp, and do not run them at less than half throttle for the first 20 minutes or so (ABC). I fly mainly magnum, saito and YS and have never messed with a painted (sarcastic) on clyinder OS.:D

RE: What Am I Missing Here?????
 

Hey Harry, straightdown into the pavement does a pretty good job of destroying an engine. Actually the only engines I actually saw destroyed running were Control Line speed engines that threw the prop blades and flew to pieces (no throttle) from turning a bazillion RPM and car and boat engines that were run at full throttle with no load ie. upside down or onto the beach or a boat engine that lost cooling.

Usually the rod let go and that took lots of other things with them. Occasionally a C/L combat engine would throw a prop or break the rod but not all that often.

RE: What Am I Missing Here?????
 

Well, I split the difference. I loaded up sixteen ounces of 15% Omega with a lot of extra castor, and ran the first tank "hot" (mainly wide open, at three turns out; IOW, she was spitting as much raw fuel as she was burning) with an 11x4 APC. The second tank had a bit of throttle work, but all in the upper power band.

Then I put the flight prop & spinner, 11x6 APC, on and ran the third tank with straight 15% Omega, going in to two turns on the big needle; again staying in the upper power band.

The fourth tank was at 1.5 turns out on the main needle. I had to lean the low end considerably, but by the end of the fourth tank the engine was holding 2200 rpm steadily at idle, smoothly transitioning to full throttle and holding 11,200 rpm without sagging; and still blowing good smoke. We'll leave it there for flying; no sense in wasting any more fuel on the bench.

In short, this OS .46 AX handled as well as any older FSR or SF I've dealt with, and settled down MUCH more quickly than some of them did. We'll see how it performs in the air, and how it holds up, but so far I've been rather impressed.

I was bit put off by some of the obvious shortcuts OS took (only four head bolts, a really cheap-looking {and loose-fitting} thrust washer/prop driver, plastic needle valve assembly, etc.) but the actual running was as good as you could ask for; IOW, absolutely no drama.

The various comments posted in this thread have been quite interesting, and I now have a greater appreciation for some of them. I'm about halfway convinced that one could run this thing just about any way he chose (except for too lean) and come out okay. Perhaps the "new" metallurgy, or whatever, isn't as el cheapo as some would think; and I believed.

The proof, of course, is in the flying and longevity. The jury is still out on that...;)

RE: What Am I Missing Here?????
 

You break it in EXACTLY like an ABC engine. DO NOT RUN IT RICH. A few clicks rich is it. OS quality is among the best in the world.