So who's doing this reviewing then?
Well I've been building and flying or driving radio controlled models for over 40 years and during that time I like to think I've built up a reasonable amount of knowledge.
I'm also a qualified electronics engineer who has worked in radio frequency, analog, digital systems and software for more than three decades. In fact I designed and built my first RC set back in 1969.
For the past nine years I've also been involved in the design and manufacture of some rather sophisticated engine technology and UAV flight control systems.
So, chances are I've been there, done that and have a huge pile of tee shirts to prove it.
Right now I'm heavily into 3D flying and enjoy all aspects of the RC hobby. I may be old but I don't feel it.
In the Pipeline
Here's just a little bit of what's to come on this site...
RC explained: Demystifying terms such as PCM, PPM dual conversion, single conversion, full-range etc., this feature will explain it all.
Cheap Chinese Engines: Just how good are those cheap Chinese glow and gas engines that sell for half the price of their "brand-name" equivalent? I put several to the test.
Build your own radio gear?: Back in the old days, building your own RC gear was not uncommon and now the arrival of 2.4GHz has made it practical again.
Review: SK90 Model Airplane Engine
JEWEL OR JUNK?
I have to admit that I've had very little luck with cheap Chinese model engines.
Although the Chinese are making some excellent engines under relatively well-known brandnames such as Magnum, ASP and SuperTigre, the lesser-known brands have tended to be a disappointment.
It seems that without someone familiar with Western expectations to watch over them, the Chinese have a lot of difficulty maintaining consistent quality control and lack a full understanding of what's required of a good model engine.
It was with some trepidation therefore that I ordered an SK90 for review purposes.
The engine I purchased cost just US$62 and how on earth could an engine that cheap be any good? I mean let's face it, an OS91 will set you back more than three times that and even a SuperTigre 90 costs over twice as much.
Look and feel
The SK90 is nicely finished. The castings are of good quality with no porosity or other obvious problems.
All machining seems to have been performed to a good standard and on inspection, no machining swarf or other potentially damaging "machining left-overs" were found inside.
This is a pretty conventional engine design-wise.
A reasonably beefy crankshaft is supported on two ball-bearings and the ringed piston runs in a chromed brass liner.
The carburetor is of a design common to most Chinese no-name engines and is secured by a single bolt, like many other modern engines.
The stock muffler is a large and heavy piece of metal of three-piece construction like those provided with Magnum/ASP engines. However, unlike the other 3-piece units I've used in the past, this one didn't work itself loose during testing.
Starting it up
Unfortunately my SK90 (having come direct from China) was provided with no instructions so I had to guess at the needle-valve setting.
After opening the main needle 2.5 turns, choking three times at full-throttle, closing the throttle to what I guessed was a high-idle and hooking up the glow heater, the engine fired right up within a couple of flicks.
This ease of starting continued throughout the test period, the SK90 bursting into life within a few flicks every time, whether hot or cold.
I ran it for just a couple of minutes -- time enough to tune a rich 2-stroke setting and make sure that it would idle without cutting.
The SK90 is ported to favor low-RPMs so I fitted a 13x8 prop which I figured would be a light enough load to not stress the engine during break-in but heavy enough to avoid over-reving.
The tank was refilled and the "Flying Trainer" AT40 I use for testing new engines was sent into the skies with the SK90 up front. Yes, putting a .90 in a .40-sized trainer is not something I'd recommend (unless you want to have an insanely fun time) but in this case it was the quickest and easiest way to get this engine into the air.
Updated: 20 Sep 2012
Here's a blog that will keep you informed just what's going on behind the scenes at RC Model Reviews and also tells you a little more about myself.
23 Mar 2010
How come there's no compatibility between different brands of transmitters and receivers? Why can't you use a cheap Chinese receiver with your Futaba FASST radio?
4 Mar 2010
Since this has become a very frequently asked question, I've posted this simple guide to getting your product, or a product you're thinking of buying reviewed here at RCModelReviews
Useful information on what's inside your servos and how they work.
Important facts you should know about the oils that are used in our model engine fuels.
How well do five different 2.4GHz systems stack up when hit by interference? The answers are here, with more to come.
Yes it does work on model airplanes but there are some limitations involved with this bargain-basement radar speed gun.
These are possibly the world's worst servos, find out exactly why you should avoid these boat-anchors at any cost.
It's cheap but can it really stack up against other glow engines in the .90 market? Find out in this review.
How does this cheap 9-channel 2.4GHz radio system perform when compared to big-name systems that can cost two or three times as much? Have the Chinese finally developed a real contender with the iMax 9X?
Does all this 2.4GHz stuff have your head spinning?
I've done my best to demystify the whole subject so if you feel like a bit of learning, this is the stuff for you!
How can you tell when your engine needs new bearings? Who has the best prices and service on replacements? Just how do you change them? Get all that information and watch a great video tutorial anyone can follow.
The Chinese are now churning out a huge number of very reasonably priced no-name servos. But are they any good?
Nicad, NiMH, Li-Ion, LiPoly, LiFePO4, A123... the range of different battery types has never been greater. So how do they differ and what type should you be using?