therotund1
May 29, 2004, 11:00 AM
!Introduction
| spec2
| @907592
| <b>Published Engine Specifications</b>
|> <b>Displacement:</b> |< 11.5cc
|> <b>Bore:</b> |< 28.5mm
|> <b>Stroke:</b> |< 22mm
|> <b>Practical RPM:</b> |< 1,800 – 11,000
|> <b>Weight w/Muffler:</b> |< 21.2 oz.
|> <b>Manufacturer:</b> |< <a href="http://magnum.globalhobby.com ">Magnum by Global</a>
|> <b>Available From:</b> |< <a href="http://www.hobbypeople.net">Hobby People</a>
!!First Impressions
@907593:From the front...
@907594:the right side...
@907595:the top...
@907596:and finally, the bottom.
The engine was adequately packed and had no damage. It came with some very good documentation including an operating manual, a maintenance sheet explaining valve settings, an exploded-view drawing with part numbers, a quick start guide, a decal sheet and a very detailed troubleshooting chart. The engine also had 2 allen wrenches for service. It did not include a feeler guage for setting the valves, any measurement data, or a glow plug.
!!Measurements
There was not a measurement chart included with the engine so these are the measurements I made. Bear with me, here goes…
|
|> <b>Crank threads:</b> |< 5/16-24
|> <b>Case width (not including mount lugs):</b> |< 40mm
|> <b>Overall case width (including mount lugs):</b> |< 57mm
|> <b>Mounting hole width (center to center):</b> |< 50mm
|> <b>Mounting hole (front to rear, center to center):</b> |< 21mm
|> <b>Drive washer back to front mounting hole:</b> |< 55mm
|> <b>Drive washer to tip of crank:</b> |< 36mm
|> <b>Mounting hole diameter:</b> |< 4mm
|> <b>Height (bottom of mount lug to valve cover):</b> |< 98mm
|> <b>Bottom of mount lug to bottom of case:</b> |< 21mm
|> <b>Drive washer to back plate:</b> |< 86mm
|> <b>Drive washer to rear of carburetor:</b> |< 113mm
|> <b>Drive washer to back of choke bracket:</b> |< 119mm
!!Details
@907597:Notice the low speed needle in the center of the throttle arm and the crankcase re-breather.
Check out the nipples in the intake and at the base of the cylinder just behind the cam cover in the photo above. These are connected together via a short piece of fuel line and make up the re-breathing crankcase vent. It expels excess oil from the nipple behind the cam cover and draws it into the intake to use it again. There are only positives to this arrangement. It provides it’s own “top end” lubricant, it’s eco-friendly and it helps keep your plane slime free.
@907598: The left side of the carburetor, the fuel inlet nipple and a great visual of the choke and it’s “handle”. I’ve sighted down the main needle to create this view.
@907599: The rear of the carburetor, showing the new offset intake manifold that centers the carburetor on the engine.
The offset manifold allows the throttle arm to be a wee bit more ARF friendly...due to a lot of manufacturers pre-drilling throttle linkages for 2 strokes. This puts the arm right in line! No more bending horseshoe shapes in the throttle rod!
!!Magnum comparison pictures...XL.52RFS (left), XL.70RFS (center) and XL.91RFS (right)
@907600:From the front...
@907601:Right side...
@907602:Left side…
@907603:Note the offset intake and it’s advantage.
@907604:Note the new flat valve cover.
@907605:Notice the open air vent nipples on the 52 and the 91 (left and right)
!!Factory Recommendations
@907606: On the stand and purring…
@907607: Purring nicely too!
I broke in the engine per the instructions. Magnum recommends that a fuel with 10% nitro and a blend of 16% Castor/synthetic oil be utilized for break in. They also recommend a 13-6 prop for break in. I used a Master Airscrew 13-6 K series and an O.S. Type F glow plug.
After running 40 ounces of fuel through it, the engine remained trouble-free. I had to richen up the low speed needle only 1/8th of a turn to get a flawless transition. I then changed to the maximum nitro content in the form of 15% Cool Power with Byron’s Castor additive.
@907608: Let’s check the valves…Magnum recommends a valve lash of between .04mm and .10mm. No adjustments were necessary after break in.
!!RPM Readings
The following RPM readings were taken at 300 RPM below absolute peak.
|
|< <b>Brand</b> |< <b>Diameter-Pitch</b> |< <b>RPM</b>
|< Master Airscrew K series |< 12-8 |< 10,500
|< same |< 13-6 |< 10,400
|< same |< 14-6 (largest recommended) |< 8,800
|< APC |< 12-7 |< 10,800
|< same |< 12-8 |< 10,600
|< same |< 13-4W |< 10,800
|< same |< 14-4W |< 9.800
|< same |< 14-4W |< (Idle) 1,900
!!Flight Testing
For detailed flight coverage, watch RC Power for an upcoming review of the Global Decathlon, including flight testing with this engine!
!!Hear Her Purrrrr....
+907609:Two minutes of tuning and testing on a stand...what a great sound! (9MB)
+907610:A quick look at the 70 running...tached. (6MB)
!!Conclusion
*The Good Stuff
*Great power.
*Value priced.
*Centered carburetor choke.
*Maintains it’s needle settings.
*The Not So Good Stuff
*No printed dimensions and measurements.
The Magnum XL.70RFS is one sweet engine. All throughout the testing, it never gave me so much as a hiccup! It’s ruggedly built, trouble free, strong and inexpensive. This is a no brainer. An engine that delivers premium performance at a value price needs your attention! It has a rapid and seamless transition, even when swinging the big flat blade 3D props. It’ll idle down to 1,900 RPM, reliably. As a matter of fact, The RPM numbers for the MA 13-6 AND the APC 14-4W props match my O.S. FS-70 S2 exactly!!!
I would not hesitate to recommend this engine to anyone.
| spec2
| @907592
| <b>Published Engine Specifications</b>
|> <b>Displacement:</b> |< 11.5cc
|> <b>Bore:</b> |< 28.5mm
|> <b>Stroke:</b> |< 22mm
|> <b>Practical RPM:</b> |< 1,800 – 11,000
|> <b>Weight w/Muffler:</b> |< 21.2 oz.
|> <b>Manufacturer:</b> |< <a href="http://magnum.globalhobby.com ">Magnum by Global</a>
|> <b>Available From:</b> |< <a href="http://www.hobbypeople.net">Hobby People</a>
!!First Impressions
@907593:From the front...
@907594:the right side...
@907595:the top...
@907596:and finally, the bottom.
The engine was adequately packed and had no damage. It came with some very good documentation including an operating manual, a maintenance sheet explaining valve settings, an exploded-view drawing with part numbers, a quick start guide, a decal sheet and a very detailed troubleshooting chart. The engine also had 2 allen wrenches for service. It did not include a feeler guage for setting the valves, any measurement data, or a glow plug.
!!Measurements
There was not a measurement chart included with the engine so these are the measurements I made. Bear with me, here goes…
|
|> <b>Crank threads:</b> |< 5/16-24
|> <b>Case width (not including mount lugs):</b> |< 40mm
|> <b>Overall case width (including mount lugs):</b> |< 57mm
|> <b>Mounting hole width (center to center):</b> |< 50mm
|> <b>Mounting hole (front to rear, center to center):</b> |< 21mm
|> <b>Drive washer back to front mounting hole:</b> |< 55mm
|> <b>Drive washer to tip of crank:</b> |< 36mm
|> <b>Mounting hole diameter:</b> |< 4mm
|> <b>Height (bottom of mount lug to valve cover):</b> |< 98mm
|> <b>Bottom of mount lug to bottom of case:</b> |< 21mm
|> <b>Drive washer to back plate:</b> |< 86mm
|> <b>Drive washer to rear of carburetor:</b> |< 113mm
|> <b>Drive washer to back of choke bracket:</b> |< 119mm
!!Details
@907597:Notice the low speed needle in the center of the throttle arm and the crankcase re-breather.
Check out the nipples in the intake and at the base of the cylinder just behind the cam cover in the photo above. These are connected together via a short piece of fuel line and make up the re-breathing crankcase vent. It expels excess oil from the nipple behind the cam cover and draws it into the intake to use it again. There are only positives to this arrangement. It provides it’s own “top end” lubricant, it’s eco-friendly and it helps keep your plane slime free.
@907598: The left side of the carburetor, the fuel inlet nipple and a great visual of the choke and it’s “handle”. I’ve sighted down the main needle to create this view.
@907599: The rear of the carburetor, showing the new offset intake manifold that centers the carburetor on the engine.
The offset manifold allows the throttle arm to be a wee bit more ARF friendly...due to a lot of manufacturers pre-drilling throttle linkages for 2 strokes. This puts the arm right in line! No more bending horseshoe shapes in the throttle rod!
!!Magnum comparison pictures...XL.52RFS (left), XL.70RFS (center) and XL.91RFS (right)
@907600:From the front...
@907601:Right side...
@907602:Left side…
@907603:Note the offset intake and it’s advantage.
@907604:Note the new flat valve cover.
@907605:Notice the open air vent nipples on the 52 and the 91 (left and right)
!!Factory Recommendations
@907606: On the stand and purring…
@907607: Purring nicely too!
I broke in the engine per the instructions. Magnum recommends that a fuel with 10% nitro and a blend of 16% Castor/synthetic oil be utilized for break in. They also recommend a 13-6 prop for break in. I used a Master Airscrew 13-6 K series and an O.S. Type F glow plug.
After running 40 ounces of fuel through it, the engine remained trouble-free. I had to richen up the low speed needle only 1/8th of a turn to get a flawless transition. I then changed to the maximum nitro content in the form of 15% Cool Power with Byron’s Castor additive.
@907608: Let’s check the valves…Magnum recommends a valve lash of between .04mm and .10mm. No adjustments were necessary after break in.
!!RPM Readings
The following RPM readings were taken at 300 RPM below absolute peak.
|
|< <b>Brand</b> |< <b>Diameter-Pitch</b> |< <b>RPM</b>
|< Master Airscrew K series |< 12-8 |< 10,500
|< same |< 13-6 |< 10,400
|< same |< 14-6 (largest recommended) |< 8,800
|< APC |< 12-7 |< 10,800
|< same |< 12-8 |< 10,600
|< same |< 13-4W |< 10,800
|< same |< 14-4W |< 9.800
|< same |< 14-4W |< (Idle) 1,900
!!Flight Testing
For detailed flight coverage, watch RC Power for an upcoming review of the Global Decathlon, including flight testing with this engine!
!!Hear Her Purrrrr....
+907609:Two minutes of tuning and testing on a stand...what a great sound! (9MB)
+907610:A quick look at the 70 running...tached. (6MB)
!!Conclusion
*The Good Stuff
*Great power.
*Value priced.
*Centered carburetor choke.
*Maintains it’s needle settings.
*The Not So Good Stuff
*No printed dimensions and measurements.
The Magnum XL.70RFS is one sweet engine. All throughout the testing, it never gave me so much as a hiccup! It’s ruggedly built, trouble free, strong and inexpensive. This is a no brainer. An engine that delivers premium performance at a value price needs your attention! It has a rapid and seamless transition, even when swinging the big flat blade 3D props. It’ll idle down to 1,900 RPM, reliably. As a matter of fact, The RPM numbers for the MA 13-6 AND the APC 14-4W props match my O.S. FS-70 S2 exactly!!!
I would not hesitate to recommend this engine to anyone.