Magnum 52 XLS
 

which prop have you found to be best on this engine for speed? and with a jett or rossi pipe. did you have to change the timing?

RE: Magnum 52 XLS
 

The Magnum 52 is a very, very powerful engine. They had two problems that they may have fixed by now ..... I hope. The first was the carb; it had a very fat mid range which can lead to a lot of dead sticks at part throttle. You need to try it with your prop/pipe combo to find out. If it has this problem it can be easily fixed by reshaping the point on the low speed screw. Search in this thread for info, post # 233. http://www.rcuniverse.com/forum/m_29...reshape/tm.htm The other problem was crankshaft failure on SOME engines when pushed hard i.e. tuned pipe & speed prop. This engine has a huge crank port = thin wall+power+run time= snap! If it happens, it happens.
On a speed plane (clean), a good starting point prop for this engine with Ultra thrust, Jett or tuned pipe running 15% would be an APC 9X9 and I would expect well over 16,000 rpm on the ground.

Good luck.

RE: Magnum 52 XLS
 

9x9 16K? I dunno about that but the Mag is a sleeper that is for sure. They have come a LONG way since the 80's :D

I would put an APC 9x8 on that thing and your F-20 should scoot out quite nicely...I'll bring some props. to the Revvers thing---

RE: Magnum 52 XLS
 

About a year and a half ago my 52 had many hard runs on it and was getting tired, than the crank went. It pulled the 9X9 just under 16K and it was not in it's prime.

RE: Magnum 52 XLS
 

My new 52 turned 16.1k with a apc 9x8. This was after 5 15min runs...

RE: Magnum 52 XLS
 

I got only 14,500rpm on apc 9x8 and Powermaster 15% on my Mag52 with Jettstream muffler. Bearings in mine lasted only 15 flights. Not nearly as durable as OS46 with same setup.

RE: Magnum 52 XLS
 

Well get ready to replace some more bearings...they are the same...

RE: Magnum 52 XLS
 

i had a .52 on an Ultra Sport 40 with tuned pipe and ran a 9x9 APC on grass and 9x10 on pavement. that engine would scream. i would have to baby that plane off the ground on a grass strip cause of the retracts and small tires but on pavement i wouldn't use up a whole lot of runway.

RE: Magnum 52 XLS
 

I had a Mach Racer with a Magnum .52XLS (an older, well run one), running a Rossi mini pipe from Morris Hobbies and a 9-7 APC. It would scream and the plane was pretty fast. I probably needed more prop. Naturally, I was not looking for mid range.

The photo was before the test flight where I used a 10-6. I did move the servos to the top and left off the gear.