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Engine basics => Engine set up tips => Topic started by: Robin_Holden on July 06, 2008, 01:23:46 AM
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Good morning from a British ex-pat in France.
Would appreciate any advice regarding a Magnum 36 I've just bought off the 'infamous' E-Bay.
Brand new , already converted to C/L with up-graded bearings.It came from a very reliable and capable source in the U.K.
Anyone out there with experience on how to get these to perform for stunt ?
Prop ? Fuel ? Head shims ?
Much obliged , all the best from the Charente.
Robin.
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Good morning from a British ex-pat in France.
Would appreciate any advice regarding a Magnum 36 I've just bought off the 'infamous' E-Bay.
Brand new , already converted to C/L with up-graded bearings.It came from a very reliable and capable source in the U.K.
Anyone out there with experience on how to get these to perform for stunt ?
Prop ? Fuel ? Head shims ?
Much obliged , all the best from the Charente.
Robin.
Hi Robin,
We follow Phil Granderson's advice on running the Magnum 36XL IIS. We use 5% nitro Sig Champion fuel (20% 1/2&1/2 oil) until it gets really hot. Then we change to 7 1/2% or 10% nitro.
Prop, is a Bolly 2 bld. 11-4. We have also used a 10" to 10 1/2" 3 bld. X 4 pitch prop.
Run it is a wet 2 cycle, just back off of solid 2 cycle.
Mongo
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Mongo , very much obliged for the info.
Kind regards from the Charente in S.W.France.
Robin.
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The 11-4 ProZinger, APC 10.5 x 4.5 and Thunder Tiger 11-4.5 are also very good and suitable props for the Magnum XL/XLS .36, if you're not inclined to break $30 props on a tipover at the schoolyard. Which Magnum .36 do you have? Round cyl. head is the XL, squarish is the XLS. The XLS is quite a bit lighter. H^^ Steve
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Hi Robin:
I suggest you check the archives on Stuka; tons (or kilograms) has been written about the Magnum 36. My own 36XLIIS (square head) has a Randy Smith needle valve as the only modification and runs a wet 2-cycle on the stock muffler in a very pipe-like run (in a Vector 40), just as the others suggest. I favor the Thunder Tiger 11 x 4.5 as it is cheap and effective and fits most plastic spinners. Here in Northern California our weather is similar to yours in SW France so the same general setup should work. I use Sig 10-10-10 fuel all year around. This is a very pleasing engine and is in wide use around here, including of course my neighbor Mr. Granderson.
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Many thanks to all the guys who have given me the advice ..... Really very much obliged.
Mines the 'square'ish ' cylinder head model.
Latest 'news' , if you can call it that , is pretty bad !!
Set it up on my bench for my usual running-in procedure for ABC engines viz , about 15/20 short [ 2 minute ] quick/rich 2-stroke runs , up to temp , then let it cool down, on a 10x4 prop.
Started first time just fine , but cut out after a minute or so .
Second time tricky , became difficult to turn over ..... The crankshaft fractured into two pieces !
First time ever with me.Never happened before.
I'm a Tigre / Enya fan and have never known this happen before.
I'm VERY careful with my running-in procedures ....luddite springs to mind .....every engine is different so get to know it in the first hour or so of careful running-in .
Now I've got to look for a new crankshaft !! C'est la vie as my neighbours say on this side of the pond.
Never mind , but thanks everyone.
Regards from the Charente , [ full of retired ex-pat Brits ! ]
Robin.
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http://www.hobbypeople.net/gallery/280419.asp (http://www.hobbypeople.net/gallery/280419.asp)
Hobby People in Calipornia are nice folks...give me very nice service. y1 Steve
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Wow, never heard of a snapped crank on one of these engines. You might consider the new Enya 40 Pro, little brother to the new 61CXS Pro, that has (according to published dimensions) the same mounting hole pattern as the Magnum. I happen to have un un-run Enya 40 (as well as the 61) and it does appear to be narrow like the Magnum. Or the not-quite-available but interesting new Evolution 36 Stunt. (Horizon Hobbies)
Since you have a little time on your hands you will presumably be going out to watch the Tour de France as it rolls through your Department tomorrow from Cholet to Chateauroux. We are watching live at 5 a.m. on the U.S. west coast.
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Robin,
I've have well over 800hours of running time on the Magnum 36 and have never seen a broken shaft. Actually, nothing has ever really broken except an occasional rear main bearing. I run them pretty hard. One caution on bearings as I noted in your original post yours has "upgraded bearings" I did this once and only once! The engine stopped in the vertical portion of the wing over and I lost a very good plane because. The lesson I learned is to just use common inexpensive bearings. They are good for at least 20 hours of actual run time and will generally last much longer. Now on the rare occasion of the stock bearing wearing out, I just replace it with a $3.50 bearing and its good for another 30 or so hours of running! Just my seven years of experience with this engine FWIW
PTG
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Yet more help ....Thanks a million fellas . Keep well and circulating !!
Robin.
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I have a Magnum 36 [ round head ] that the front bearings are suspect after a crash .
Never tried to change bearings before , wondered where to get them and how difficult it is to change them ?
Bill
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Boca Bearings is a good supplier, just match ID, OD, and thickness, usually in mms.
To get the bearings out, remove the crank then heat the crankcase block in the oven at about 200 degrees, suggest not over 250. Take the heated block out and gently tap the case on a block of wood and the bearings should fall out. Rear bearing first, then the front is easily removed by pushing out with a dowel.
Do the opposite for installation, but use the crank as an alignment fixture. Heat the case, put the rear bearing on the crank, then install the crank in the case. A GENTLE push with a large dowel will help to insure the bearing is seated in the case. Put the front bearing on the crank snout and push into place with a wooden block with hole in the center. Use a press, or large vise, with wooden blocks to keep from brinnelling the bearing balls into the races. Tapping here is a no-no, too much chance of ball damage.
Hope Randy agrees with the above!
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Final posting I hope regarding my cantankerous Magnum !
Bought a new crankshaft from Just Engines in the U.K , who are the ASP importers.
Reliable outfit , my new 'shaft arrived after a couple of days and the postal charge was very modest [ un-like some I might mention ! ].
On the bench and after just a few flicks she was away.
Need to get a new NVA as it's set-up with a 'short'ish ' O.S one and the hole in the spray bar is off-set.
I'm sure Randy will have one after your Nats is over .
Managed a dozen short 2 minute fast/rich runs and it's running just fine.
Impressed with the strong 4-stroke ....Oh , I installed an extra head shim.
So again thanks to all who've contributed with help .....Very much obliged .
It's Sunday , around 10 am so I must be off and get ready to go to the field , wind permitting. Regards from the Charente ,
Robin.
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Final posting I hope regarding my cantankerous Magnum !
Bought a new crankshaft from Just Engines in the U.K , who are the ASP importers.
Reliable outfit , my new 'shaft arrived after a couple of days and the postal charge was very modest [ un-like some I might mention ! ].
On the bench and after just a few flicks she was away.
Need to get a new NVA as it's set-up with a 'short'ish ' O.S one and the hole in the spray bar is off-set.
I'm sure Randy will have one after your Nats is over .
Managed a dozen short 2 minute fast/rich runs and it's running just fine.
Impressed with the strong 4-stroke ....Oh , I installed an extra head shim.
So again thanks to all who've contributed with help .....Very much obliged .
It's Sunday , around 10 am so I must be off and get ready to go to the field , wind permitting. Regards from the Charente ,
Robin.
Hi Robin
If you need any parts I will be glad to help you with anything you need, I have setup 100s of these motors, and have most any part you will need
Don't worry about putting good quality bearings in them as I have done the same 100s of times, their is nothing in my high end bearing that wil cause any "ills" to the motor, they will just last much longer, however I also have the stock ones too, as well as the ventuires and the standard PA large NVA assembly fits it very wekk
Stock front bearings are $2.00 each these are shielded
Sealed front bearings are 11.00 each
Phenolic cage hi quality rear bearings are 9.00 each
stock rear bearings are 6.00 each
I sent a PM about the other engine you asked about
Regards
Randy