Global* has been refining its Magnum line of 4-stroke engines for more than 5 years, and judging by this latest, .30 displacement offering, the years of R&D work have paid off. This is one potent, nice-running little machine. I've run almost every brand of 4- stroke: Enya, O.S., Saito, Webra, HP, Lazer -even a Czech Velkom-but this is the first time I've sat down to a Magnum, and I wish I had done it a lot sooner! I should have had a clue when I opened the box; the instructions for the .30 are among the best, most complete I've ever seen. Not only are they very clearly written, but they also contain useful glow-engine information that the novice (and not-so- "novice," for that matter) modeler will find valuable in the future. Only the tools were a bit disappointing. The included Allen wrenches were made of too-soft metal for the work they needed to perform. All tools should, obviously, be made of high-grade steel, but this is especially true of small Allen wrenches. At a time when tools seem to be disappearing entirely from 4-stroke engine boxes, I guess this is a picky complaint. Still, if you're going to include them then make them of good, usable quality. BREAK-IN Break-in is dealt with extensively in the instruction booklet, and I suggest you pay close attention to Global's advice. The instructions say to perform all break-in with a fuel containing no less than 20- -percent lubricant and no more than 10-percent nitro. You are also told to break the engine in after it has been installed in an airplane. Personally, I do all my breaking-in on the bench because I feel I have better control. I ran the .30 for a series of short runs on an APC 9x5 for a total of 30 minutes on a very rich setting using Wildcat's* 5-percent break-in fuel with 20-percent oil that consisted of a synthetic/castor blend (80/20). After that, I switched to Wildcat's 15-percent nitro Premium Extra fuel with an 18- percent oil con- tent and ran the .30 for another 20 minutes on a setting that was still somewhat rich, this time with short periods of mixture leaning. At the beginning of the break-in process, I did need to use an electric starter because the ring had not sufficiently seated against the sleeve, and this is necessary for good compression and hand-starting. Don't go looking for easy hand-starting, good performance, good idle, or even good throttle response until most of this break-in time has elapsed because only then will the ring begin to seat properly and only then will optimum performance be realized. After the ring was seated, however, compression seal was very good and got even better during testing. Some engines need more breaking in than others. Generally-very generally - I've found that the longer an engine's break-in takes, the longer the engine lasts-Enya and SuperTigre, for example. An exception to this is Saito; these engines have a unique combination of ringed pistons running in a chrome-plated sleeve. They almost run right out of the box, and they last a very long time. PERFORMANCE All performance tests were carried out using an 0.5. "F" glow plug. I always use this plug; not only to make certain that all " Air Power" 4-stroke tests are as consistent as possible, but also because I believe it is simply the best 4-stroke plug presently available and gives superior idle and throttle response. Incidentally, the Magnum's idle readings were exceptionally good. Using my very accurate TNC tachometer, I got 2,300 to 2,500rpm on an A PC 11x4 and 2,100 to 2,300rpm on an A PC 12x4. These readings are good for any small-displacement glow engine, but for a small 4-stroke, they're excellent. After leaning the low-end mixture needle slightly, throttle response was also quite good. As the performance test proceeded, I became more impressed with this little engine; it's a powerhouse. In fact, it's the most powerful in its category that I've test- ed yet. I was surprised and impressed. On an A PC 10x6, the .30 turned up at 9,820rpm. If the humidity had not been so high (92 percent) during the test, I'm sure the 10,000rpm mark would have been easily attained. Because it has a broad power band, the Magnum has the ability to turn both high-pitch, smaller diameter props at sufficiently high rpm for cleaner designs as well as fine-pitch, larger diameter props that are better for higher drag types such as scale biplanes. Vibration levels, a pet peeve of mine, were quite low. The Magnum .30 pleasantly surprised me. The engine offers very good power and running characteristics at a fantastic price. The .30 can be purchased for about $110* - $40 to $50 less than the competition. This is my first Magnum 4-stroke test, so I can't comment firsthand about its longevity, but I do know a number of guys who are running Magnum 4-strokes for a second season now with no problems at all. You can bet I'll be running more tests on larger Magnum 4-strokes to see whether they're as good as their little brother. If they are, you 4-stroke lovers are going to find a lot of value in the name Magnum, especially considering the relatively high cost of 4-strokes in general when compared with 2-strokes. *At time of review, current price = 129.99 |
