Phoenix Top Star 60

[crankestein]

A friend had it gathering dust in the basement for years w a Magnum XL .52 two stroke, shut bearings, servo mounts loose, old electronics, incorrect fuel tank relation to the carb, had to reroute and make new firewall line holes.

Went w a Magnum XL .61 w some port work w a OS flap carb, FHSS 8 channel rx, fresh 2200mah NIHM battery, reinforce firewall, servo mounts and ready for the its maiden. Had no manual and no online info, guessed it the CG w some common sense. Almost no up elevator when flying inverted.

Did some basic 3D, but w the current cg is not ideal or easy to do.

13x6 ASP propeller
10% Omega fuel

[Alpha]

Looking good! How did you go about reworking the ports? What was the problem? I'm guessing after that many years everything was stuck together... I had an old Saito as a hand me down that seemed it have spent a decade in the core of the earth. After a year of fiddling and a minor rebuild though it ran just fine.

[crankestein]

The porting is done on the sleeve, the main intake and both boost ports. With a small fine dremmel I make a fine knife edge type line in an angle pointing up and away from the exhaust. The key is to make a small channel and gives a jetting effect. I can tell the difference in transition and peak rpms, the engine sounds crisper giving that raspy note on the exhaust.
I dobt go too big, else engine will load up and be rough. I start w two small lines on the main, and one line per each port.

I notice the engine tends to run cooler. There is another line I do on the button top near the glow plug, and that gives it crazy top end but not all engines take it well. I have done the button mod on rc buggies and the engine is very snappy.


Will see if I snap a few photos and upload.

[Alpha]

I'd appreciate some photos, your technique sounds interesting and I haven't tried a Dremel. I've used files and lapping stones, which took forever as some areas are difficult to reach and the work overall is inconsistent at best. I tried to chuck it up in a machinist's vice to use a mill, but the endmill wasn't long enough.

Are your running temps noticeably cooler? Or just slight?

[crankestein]

I apologize, completely missed your reply.

Been busy this past week at work, and almost no time to log in and even tinker or fly the planes.

Ebay sells a set of fine dremel bits. The work is done on the sleeve, not on the crankcase. So its simple to pull it out and work on it.

[crankestein]

Here are a few shots.

The crank porting is very similar to the one done on Jett engines. Had unlimited vertical on a Alpha 40 trainer which is a very heavy plane.

APC 11x7, easy to tune, no dead sticks, nice raspy sound and clean transition.

It would toss around the Alpha no problems, loops, rolls, climb and then glide back down. Its one of my favorite engines, people at the field ask what engine is it because of how quick and maintains the rpm, lets go off the throttle and is as if it shutdown, but stays mellow at idle.

#1 picture of the crank, cut at an angle, helps on fuel flow.
#2 picfure, cut on the side of the weight to compensate for the amount cut on the center top.

#3 Crank has a porting bowl from side to side and then port the mouth like s bowl funnel to open up as if a trumpet.

#4 and #5 the sleeve has very fine channels done pointing up and at an angle on the side ports TOWARD the main boost port. Always at an angle away from the exhaust port.

[crankestein]

Unfortunately it was way too much for the plane and on its maiden day the wings gave up,the center wing rod in about its 4th flight doing a crazy loop ksmikaze down at full throttle....

It sure was a lot of fun, will miss the Alpha....

Its strange, the airplane crashed on this yr 2019, on the number posted on the wings, an airplane that was about 7 yrs old had a stamp of 2019, ja ja

[RCjunky]

I just picked up a Top Star. I'm trying to get it balanced. It wants a lot of nose weight. My starting point is on the spar. Any recommendations would be appreciated.

[crankestein]

This plane will take a two stroke .61 and still needs some nose weight. Mine has a Magnum XL .61 w the stock pipe and about 3/4 ounces added.

It flies fast, and fly extremely slow w a predictable stall, rolls and snaps are quick, sometimes wonder how it does not rip the wings.