Straight up, I am biased in favor of OS MAX and Yamada engines. Yes, there are other brands, but it's hard to beat their latest small block engines; especially the OS MAX 55HZ series simply because they start and run well, are easy to tune, and hold needle settings perfectly.
These OS ENGINES come in two flavors; the 55HZ-Hyper (15630), which relies on muffler pressure, and the 55HZ-R (15650), which is the version with their Demand Regulated System (DRS). These DRS engines make the same horsepower but cost more because of the added expense of producing the pressure regulation components.
Note; DRS is very, very similar to how Yamada operate their 60SR engine using crankcase pressure instead of muffler pressure. This is a great example of a company, OS in this instance, responding to the competition.
Which is better for you; muffler-pressure, or one of the pressure-systems produced by OS and Yamada? Let's touch on this, next!
Selecting an 55HZ-H
My advice for 99% of you is to buy the HZ-H (-H for Hyper). Especially if you're a Sunday-flier, prefer easy tuning, and/or if you're a seasoned pilot flying for fun.
From where am I coming? I'm an ordinary club pilot. I fly for my own satisfaction and can be pigeonholed perfectly by the term 'sport pilot'. The point of this article is merely to guide you because we don't sell engines (thus, no dog in the hunt).
Anyway, because I'm a pretty decent stick, and because I'm perfectly satisfied with both the power-output and easy handling of these -H engines, then I recommend them. Honestly? My only bitch is what they cost.
By the way, when I self-label myself as a sport pilot it's because I absolutely relish driving home wearing a big silly grin from a good day of flying – and from not having crashed! Honestly, I get enough stress at work Monday-Friday and thus, the stress of performing higher risk 3D maneuvers just doesn't appeal.
So the grin means my model is in one piece. I've been so pleased my face hurts from smiling! It's all down to my not being characterized as a big time risk taker because I don't relish repairing my heli after dumb-thumbing it into terra firma!
Minor point being, I fly for fun. Sure, I may do a few tricks like loops and rolls, fly inverted a little bit, do some pirouettes, and especially, shoot some autos – but – I'm never doing tick-tocks or piroflips six feet off the deck. Why not? Honestly? It's because 3D ain't my thing!
Major point being, if your flight profile is similar to mine, and your P6 is destined for sport or scale, then I suspect an HZ-H is the best engine for you, too!
Selecting an OS 55HZ-R or Yamada 60SR
Switching gears; if your vision of fun involves ripping the sky like a dragonfly on cocaine then straight up, I advise buying either the OS MAX 55HZ-R DRS Ringed engine or the Yamada 60SR. But just because these are the preferred engines amongst 3D aficionados doesn't make them the right choice for 'your' P6 build.
Reason is regulated engines can be a bit more finicky to deal with. E.g a higher emphasis on filtration, selecting the perfect plug, getting throttle transition perfect, and just dealing with an engine at a higher level.
So unless you're actually performing aggressive 3D maneuvers, then you may rue buying a regulated engine. Saying, don't later go whinging about nobody telling you tuning and keeping them operating perfectly can be a pain in the ass.
Basically, regulated engines are 'the' perfect example of; spending an extra $100 doesn't mean better for you! Consider yourself warned.
Exhaust system
Anyway, as regards the exhaust system for these two OS models, they both use the same one; it's their OS-brand PowerBoost Pipe III. Yes, it works great, but they're also really, really expensive. Worth it? I don't think so. Why not?
In part, it's because I have a dog in the hunt. But also in part due to my experience running engines equipped with both it and our ProPipe 55v3. Point being, before reaching for your wallet, since the engine's sound and performance will be similar with either PowerBoost or ProPipe, then a major consideration for most comes in regards to the latter saving you $100.
Honestly? If a hundred bucks doesn't move your needle, then don't bother checking it out. But if you're intrigued, then to learn more, review this article; Exhaust system.
So next, let's change subjects because as it turns out, for some of you, there's another way into 600-class helis. One, which isn't so pricey.
Saying if a new engine and exhaust combo going for between $600-700 doesn't especially appeal, then there's another way . . . so keep reading!
Alternative new engines
First, yes, there are other new engines available; some less costly, some equally so, and some even more costly. These include the Thunder Tiger 53H, Novarossi Rex R57HR3DS, plus Align RC55H who offer what looks like a dead ringer (some claim it's made by OS, themselves, I have my doubts).
Anyway, the important thing is these are all bolt-ins for the P6 (meaning no modification necessary). However, one piece of advice; when buying an engine, what you're 'really' buying is the carburetor.
Really saying engine brand doesn't always matter because it depends to a certain degree on you and your engine tuning skills. Remember, as long as it has fuel, compression, and ignition, then 'any' engine will run.
But the reason cheap engines proliferate on fixed wing models versus helicopters is because they spend large amounts of time at wide open throttle, and while they need to be decent at idle, transitioning off part throttle isn't a principal requirement.
Helicopters are another story. This is because the real question becomes; how does it carburate at part throttle? Think in terms of whilst hovering and during part throttle transitions. And it's at part throttle, especially, where OS and Yamada made their bones.
Part throttle ops is why these two brands dominate amongst heli aficionados. Basically, with the exception of Yamada, nobody equals OS MAX carbs for consistent fit. So because part throttle excellence affects the joy of flying helicopters, then 'this' is why I recommend these two products as the right engine for most people.
And note; this is 100% down to us trying to guide you best we can. Whilst the decision is on you, we're really about you being happy. Meanwhile, and as it turns out . . . brand new engines aren't the only game in town.
Used engines
This brings us to our 2nd observation . . . and it's also as regards happiness. Basically, just like there's a market for used cars, a used engine may appeal when it comes to making you perfectly happy. True, if you have certain skills and experience.
So next, let's touch on the used engine approach to putting a model into the air. Do this with an article titled: About used engines.
