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HeliProz R'C Heli Engines Index
HeliProz is a Fully Authorized US dealer for all three Major Brand R/C Helicopter Engines. More imortant we have a staff who build and flies R/C helis and we can help you choose the RIGHT engine for your needs and budgets. When you go to our online catalog, remember that we follow the Minimum Advertisd Price policies on OS Engines, so the posted price will always be higher than our actual selling price. Either call or e-mail for pricing, or just order online and we'll adjust the price DOWN to our actual selling price when we process your order. FREE UPS ground in 48 states on all orders over $100
OS .32SXH is the most dependable and consistent of all 30s on the market.   ThunderTiger 36 PRO is a bit of a gamble, price is low. .32 - .36 Engines There are several engines in this class, which is by far the biggest selling size of RC heli engine. Most people start out with a "thirty" sized helicopter due to the lower cost when compared to larger helis. The number one choice in this class is easy ­ the OS .32 SXH engine wins by a mile. Reasonably priced and consistently reliable, the OS .32 is the engine that most 30-sized helis are designed for. With an ABN design (aluminum/brass/nickel) that breaks in pretty quickly and lasts a long time, the OS is extremely user friendly and easy to adjust. It runs fine on 15% nitro and even better in 30% nitro. Timing allows very smooth running on any decent muffler but still responds nicely to tuned pipes. We strongly recommend you use a throttle extension such as D'Best Co's CNC Aluminum units, as the stock arm has a nasty habit of breaking. NOTE ­ as with all OS engines we are not allowed to show our actual selling price on the .32 ­ so you have to call or e-mail us to find out our actual selling price. WE ARE THE BEST SOURCE FOR ALL OS ENGINES ­ Best Pricing, Best Service, and Best Support! Our second biggest selling engine in this size range is the ThunderTiger .36 Pro. The reason it sells is the price ­ we sell it at around $75. If you get a good one it is a real winner ­ definitely has a small amount of added power compared to the OS. The design is rugged and workable. Unfortunately the consistency is poor ­ some of the TT36 engines are superb, some are garbage, and the rest are in between. Ace has been good about replacing bad engines for customers. ABC construction on this engine takes a while to break in but also takes a while to wear out. Mounting dimensions for the engine and it's muffler are identical to the OS .32SXH. Webra engines are well designed but fussy. The Webra 35 is a good choice only if you want to run very low nitro. The carb is not as good as the OS, and even with all of the extra shims installed the Webras don't like nitro. They are well made and have similar ­ but not identical ­ mounting dimensions to the OS .32. The Webras need a fairly extended break in. The Enya 35 is the least powerful and least compatible engine we stock and is an old and tired design. We normally only sell this engine in the ARF Shuttle Challenge ­ it's generally fine in that basic trainer application but just not as much bang for the buck as the OS .32 SXH.
46-50 engines In the old days there were not many choices. These days the decision is even easier! The new OS .50 SXH is an absolutely amazing engine! With an entirely new carburetor design, the OS .50 is the most powerful and reliable engine in this size range that has ever been available, and not by just a small amount! We've run many cases of fuel through the OS 50s and continue to be very impressed. The 2-needle carb is sheer simplicity to adjust and any setting that's slightly rich of peak will produce extremely smooth and extremely powerful operation. The 50 has identical mounting dimensions to the old OS .46 except the 50's crankshaft doesn't have the flat spot on it. BUT you can NOT use your old 46 sized muffler on the 50 ­ it puts out WAY too much power (and thus way too much exhaust volume) for the old 46 mufflers. The best muffler choice is the Hatori 50 muffler. You don't need a tuned pipe for any heli with this engine. NOTE ­ as with all OS engines we are not allowed to show our actual selling price ­ so you have to call or e-mail us to find out our actual selling price. WE ARE THE BEST SOURCE FOR ALL OS ENGINES ­ Best Pricing, Best Service, and Best Support! OS .46FXH and ThunderTigre 46 Pro. What can we say ­ the OS 46 can be made bearable if you modify the carb. The ThunderTiger 46 Pro is a bomb and we refuse to sell it. NEITHER is in the same power or smoothness league as the OS .50. Do yourself a favor and pass on either of these engines unless you absolutely can't afford the OS 50 ­ then go with the OS .46 and modify the carb. ThunderTiger 50 We have not had any of these. Initial user reports are very much mixed. We'll wait to see how they perform before we voice an opinion. Webra 50 See Webra 35. Rugged and okay running, but not compatible dimensions and it hates nitro. We stock these because some guys will not spend the $$ for the higher nitro fuels in which case the Webra is a good choice.
The OS .61SXH-WC is the most powerful .61 heli engine that OS has ever sold.   The YS .61's main claim to fame is SMOOTH power and a no-fuss needle valve. Sixtys and Seventies Not the era, the engines! (So put away the bell bottoms and tie dies!) This is the big boy class, or at least it was until recently. The new kid on the block is a new Ringed .70 from ThunderTiger. Unlike the other TT engines, we haven't gotten nearly as much negative feedback on the 70. It seems to have adequate power and decent reliability. Not great, but not horrible ­ which makes it Thunder Tiger's best heli engine so far. At the top of the heap are the OS .61 SXH-WC and the YS .61 ST2. These are the two most powerful and popular engines in this size class. They produce pretty close to identical power output but do so in very different ways. This is the closest matched pair of engines in helis and the choice is difficult ­ although either engine will make you very happy! OS .61 SXH-WC (World Champion) The OS .61SXH-WC is the most powerful .61 heli engine that OS has ever sold. It uses aggressive porting and timing and a 3-needlle carburetor to allow very strong power on mid to hi-nitro fuels. The WC responds very well to a tuned pipe, in which case it beats the YS for power. On a muffler the OS and YS have almost identical power. Most helis come with mounts, collets and flywheels that accept the OS engines without modification. The 8x1mm crankshaft threads on the YS usually require different collets and/or flywheel modifications. The WC can be somewhat fussy to tune, and it will only run smooth if you set it slightly richer than you would expect. We give the nod to the OS by a slim margin, only because it has much better parts support, mounting compatibility, and costs about 10% less than the YS .61. NOTE ­ as with all OS engines we are not allowed to show our actual selling price ­ so you have to call or e-mail us to find out our actual selling price. WE ARE THE BEST SOURCE FOR ALL OS ENGINES ­ Best Pricing, Best Service, and Best Support! YS .61 ST2 The YS .61's main claim to fame is SMOOTH power and a no-fuss needle valve. On a nice spring day you set the needle slightly rich and then fly until winter. (With some stops for fuel, charging, work and other pesky interruptions!) It's a VERY smooth engine. The YS is not very happy with tuned pipes and generally runs best with a good muffler. Besides price and mounting issues, the only downside to the YS is the somewhat complex method in which it gets its strong, smooth power. The unique fuel tank pressurization system has a lot more maintenance points than the "plain old" venturi type carb on other engines. ALL fuel lines must be pristine, and any dirt in the fuel can cause problems with the check valve, regulator ports, diaphram AND needle. Again, it's a VERY good engine and if you don't mind trading more complexity (and somewhat higher cost) for more consistent needle setting, it's a great choice. OS .61 LXH This is OS's "Sport" engine. It has simple to adjust two-needle carb that gives consistently smooth runs. At about 10% less than the WC the LXH is aimed at the sport flyer or beginner who wants an easy to run engine and doesn't mind the lower power output. A great choice if that's the sort of engine you are looking for. NOTE ­ as with all OS engines we are not allowed to show our actual selling price on the .32 ­ so you have to call or e-mail us to find out our actual selling price. WE ARE THE BEST SOURCE FOR ALL OS ENGINES ­ Best Pricing, Best Service, and Best Support!
The OS .91 SXH is our pick for engine of the year and then some.     YS Fans will love the power boost from the new YS 80 Heli Engine - with the same SMOOTH power as the .61ST2 BIG GUNS ­ The YS .80 and the OS .91 SXH-WC HeliProz was among the first to have these engines and we have run a lot of fuel through both. (We have also sold more than any other dealers and have a lot of customer feedback). Let's just say these are SUPER engines! The YS 80 is identical in mounting dimensions and identical in operation to the YS .61 ST2. Again, it is simple to adjust and VERY smooth and consistent. It has a definite power boost over the YS .61 ­ not just a little either! Idle and transition are excellent. Yamada's instructions recommend a gear ratio of 7.0 to 7.5 which is very strange ­ unless you run a 2200 rpm head speed (which will destroy most current helis!) you will find that an 8.0 to 8.4 ratio will put the engine in it's peak torque range. YS 61 mufflers will NOT work on the 80, as it has much higher exhaust volume and needs more expansion area. The KSJ 80 muffler is our favorite. We've run the YS 80 in our Vigors with both the standard 9.3 ratio and with the 8.4 ratio. Even with the 9.3 it ran fine and had tons of power. But you must keep head speed down to avoid over-revving, which of course slows control response. With the optional 8.4 ratio the engine is obviously happier and more responsive. Again, it's about $10-$20 more expensive than the OS .91 but you YS fans will be extremely happy with the power boost. AND THE WINNER and STILL CHAMPION. The OS .91 SXH is our pick for engine of the year and then some. Free from the old FAI 10cc displacement limit, OS tossed the 3-needle carb and (overly?) aggressive porting and gives us more power the old-fashioned American way ­ 50% more cubic inches!! The results are stunning. This engine drops right in to any heli that the OS 60 fits. The 2-needle carb is similar in looks and design to that on the OS .50 SXH and is equally spectacular in operation. Set it rich and fly all year! This is one cool-runnning, smooth operator and it puts out obscene amounts of power! Your old 60 muffler will NOT work, use the new KSJ 90 muffler or the new high volume Hatoris. You may also need to upgrade to a 24 volt Dynatron starter as the ringed engine is very tight and stays that way. But the upgrades are definitely worth it! We have many cases through the OS .91SXH and it's the best heli engine we've ever seen. The power output is WAY beyond the hottest 60 you have seen, and the power is SMOOTH. Idle and transition are excellent. With the standard ratio in our Vigor the engine seemed very happy and power was exceptional. Then we put the 8.4 gears in and HOLY COW! What a Monster! Running slightly rich (and ridiculously cool, CHT measured at 195 degrees F after an entire tank of flipping ­ on a 94 degree day!) the power and acceleration were the best we've flown. The only thing even close is the YS 80. Speaking of cool, one of the Grey Market Japanese vendors keeps trying to convince us that the engine runs hot and so you need some "special" aftermarket cooling head. Of course you have NO WARRANTY in this country when you buy grey market so there's no point worrying about your warranty being voided, but it is NOT needed! At this point (End of 2001) we have sold more OS .91s and run more fuel through OS .91s than ALL OTHER US DEALERS COMBINED and we have had NO cooling issues at all. NONE. And we haven't had a SINGLE CUSTOMER experience any cooling problems either. No doubt some enterprising US dealer will come out with an aftermarket cooling head but we strongly advise against voiding your EXCELLENT warranty by installing one. If you are having cooling problems we'd like to hear about it. NOTE ­ as with all OS engines we are not allowed to show our actual selling price ­ so you have to call or e-mail us to find out our actual selling price. WE ARE THE BEST SOURCE FOR ALL OS ENGINES ­ Best Pricing, Best Service, and Best Support!