Engines

	Engines
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Note: I have found when you install an engine, it is not a bolt-n-go type install like you would think. You have to angle the engine as you tighten the bolts so that it aligns correctly with the start shaft. If the you turn the start coupler and it does not turn freely backwards, then it must not be aligned straight. I found that I could not get the start coupler to be totally free so I ended up having to drill out the engine mount holes using an 1/8" bit. This allowed the engine to sit at the proper angle relative to the start shaft. The start shaft turned much easier after that.

Thunder Tiger Pro36H	This motor is very powerful. The carb is very sensitive. One click will make a big change. There does seem to be some inconsistencies in manufacturing. Some have reported they have found the o-rings in the carb have been cut. I have seen extra pieces of the rubber from the o-ring mold process come off in the carb. I have found many of the throttle arm nuts were not tight, also the nut (on the main needle side) that holds the carb together came off. One person told me he had one that the crankshaft had 0.009" runout. Having said all this, I must say I have over 400 flights on the one that came in my 1st Raptor and it is running good. Although there does seem to be some engines with manufacturing flaws, I personally have seen the majority of the problems were with improper tuning of the engine. This engine does have a rich spot at 1/3 throttle for the first few gallons. Also it needs to be run rich on the low end. If the engine is not tuned right, this rich spot is more prominent and can be frustrating. Also I don't think the heat sink on this engine is good enough. When the temperatures around here got hot, the engine was overheating until I made a fan shroud extension. This is also one of the reasons you have to run a rich low speed settings. Otherwise it would try to overheat in descents and hovering. Another problem is the o-ring on the main needle wears out and causes air leaks, they did give two extras with the engine, but if they had designed the o-ring to sit farther out from the threads, then engine vibrations would not wear it out because the pivot point would be further away.
Leo37	This is a good engine. I like it a lot. The carb is very good. It even has a finer adjustment then an OS carb. The power seems to be slightly more then my TT36, but where it really shows off is in how well it hangs in when loaded. In other words during a hard manuever the blade rpm would drop off more on the TT36 then with the Leo37. Another advantage to this engine is that the heat sink is made right. It alows proper cooling. Plus the manufacturing quality appears to be much better. I don't know many people with these engines so I can't give as detailed a report as I did with the TT36, but from looking over this engine it seems to have a 'made to last' type design. The engine runs very smooth and consistent. I do recommend this motor if you want the power of the TT36 but the ease of adjustment of an OS. Note: I had to use an KSJ-279 Aluminum Throttle Lever OS32 to the carb lever would not hit the muffler I use. It cleared the stock muffler, but not my Hatori.
OS 32	I have not used one of these, but most people seem to think it's key feature is reliability.
Webra 35H Competition	I have heard this engine is very powerful on 15% fuel. I asked a friend of mine, that has this engine in one of his Raptors, what he thinks about it. He said it still does not have a lot of power, but also figures it's not fully broke in yet. What he means by not enough power, is that it bogs while he is doing flips, where his OS32 does not. I have heard several say the Webra is very strong after the break-in period.
SH Pro 32 Heli engine	http://www.gr8lakesrc.com/sh32heli.html
OS 50 SX-H	Note: testing done with Gr8Lakes custom 46 muffler Good engine but the carburetor does not have a linear mixture curve. Some have done the 'cat-eye' mod with great sucess. This procedure has you grind the opening in the low speed needle in a certain spot. Back before this mod was ever thought of I did get mine running great but it took a lot of tinkering. This engine does suck fuel more then the 30 class. I have estimated I'm using up 1.1 ounces per minute. If you get the engine, get the bigger PV0119 tank (Note this is for the v1, the Raptor 50v1, 30v2, and 50v2 already have a large tank) and you may also want to run a 2oz header tank also. Power is great! Price is nearly the same as a 60 engine, but you are getting a much higher quality engine then the 30 class.
OS 50 with Hyper Head	This engine has a correct carburetor. One of the guys that I fly with has one and it is doing much better then the OS 50SX-H he and I had.
TT 50	After my OS 50SX-H wear out I installed a TT 50 and really like this engine. I have about 500 flights on it so far. The engine has a much better carburetor then the OS 50SX-H. It runs smoother, has just as much power, uses less fuel, and cost a lot less. After switching the the TT50 there was no way I was going to rebuild that OS I had!
OS 61 LX	This engine has a lot of power! At first I had the Hatori SAB9II muffler on it and the idle had to be sloppy rich and it wasn't easy to tune. Later I put a Weston 1pc Genesis muffler on it and that totally changed the engine. It added even more power, but the best part is the engine ran smoother and idled great!