john josey

Looks good. Let us know how it goes.

Remember though, the rudder is super sensitive a WOT. You just have to breath on it for slow or point rolls....good luck.

PAK26499

My Feedback: (3)

If given the choice between the two which one would you guys choose for the Magnum to start off with:

OS. 55AX with the Red Jettstream with I currently have mounted, broken in and ready to go?

or

Evolution .60NX with the Red Jettstream?


I have plenty of experience with the OS's and am comfortable with them but reading the tach forums the EVO is better suited for high RPM. I had a .60NX briefly last year but sold it after what I thought was engine issues. Turns out after I sold it I discovered it was not the engine but the tank that had issues. Poor lazy diagnostics on my part assuming it was just a bum engine. Anyways, I am now able to get a hold of another one for pretty cheap and give it another go if it would be worth it, but have little knowledge of the Evo's and wonder about the longevity of the engine.

If I go with the EVO I would gladly put the OS on my Escapade with the stock muffler for some quiet sunday flying.

Thanks in advance.

Rudeboy

Still have one that I fly regularly... Old West 50 with new P/L set and new bearings... The P/L set was so tight when new I couldn't get it started (scary tight), heated it up with an airgun and started it with an electric starter... it has been one of my strongest running engines ever since... It has a couple of gallons through it now, and it's still nice and tight (but hand-startable now). I prefer the starter though, cause I just don't trust that cold squeak when flooded with fresh fuel. The Jett rods look definitely beefier...

john josey

I used a heatgun on my own west for the first run. I had visions of shreding the rod on that first run.

MJD

My Feedback: (1)

I did shed the rod on the first run of my .50V1. It chewed up and split the big end about 20 seconds or so in, running at the 2-4 break point warming up on a 9-6 prop. Weston initially tried to blame it on the fuel (Omega 10% syn/cas), but I pointed out that if they wish to export engines to North America they better realize that is pretty much a standard. Weston repaired it and returned the engine to me very quickly, I commend them for their service. Since then it's run like a champ.

First run rod failure is a big reason Jett runs their engines before shipping.

Rudeboy

They have a "fitting control issue" if you ask me...
I doubt they hand fit pistons to liners.

My first engine was ok, felt about like a Jett or Nelson Q500 engine when it comes to tightness (what an expression :-P ).... it started and handled like a charm, but it threw a tang from one of the the wrist pin clips pretty early on after I started messing with the header. Messed up the liner big time.

So I ordered a new P/L set, and it came complete with the rod and everything (didn't ask for that)... It was just too tight: no way you would force that piston through TDC without shredding the rod. And I tried: spinned my Sullivan starter up on 12V, then hit the spinner...and it just stuck every time. I had to pull the engine off the test stand a couple of times to pull the backplate to see in what direction I should start forcing things to free that piston....scared the heck out of me! I think the only thing that saved that rod was the fact that I never made it past TDC without heating the engine. If I had hit it with the starter after being stuck I probably would have stretched the big end sooner or later.

So I ended up using a propane torch actually, since my heatgun gave out.

I like my engines tight, but THAT tight is asking for problems...people are invariably going to try to start that thing up, even if it's too tight. And they'll break. They honour their warranty, but that doesn't apply when you order a new p/l set.

Dub is on the money...I really like his "I take the first risk" service!
Nothing but excellent service coming from that man.

john josey

 I think i might just have been lucky with mine and i know he frowns upon using any other fuel than his own.

MJD

My Feedback: (1)

They told me they had run a TD .049 on a shakedown test on their 8% oil fuel and had no problems. I'm sure it may be fine short term, but I'd like to see the fits and the ball and socket joint after a while. Mind you their Magnums go over 200mph while in North America they seem to be 40-50mph slower. Maybe our laws of physics are different too.

combatpigg

My Feedback: (3)

I've restored a couple old engines by honing out the iron liners and making new pistons from steel. The final fitting is really tedious because the piston/rod is used like a lapping tool in the tapered liner. It is a good idea to make a special rod just for lapping the piston to the liner out of steel.
It really is amazing how the factories are able to quickly spit out engines with perfect fits as tight as they are.

bob27s

My Feedback: (19)

Just following the thread

PAK26499

My Feedback: (3)

Ready to roll with engine runs complete.

SJ .50 powered.

PAK26499

My Feedback: (3)

Lets try photo upload again.......

MJD

My Feedback: (1)

Yeehah, looking forward to flight test report.

What prop is that? Looks kind of big..

PAK26499

My Feedback: (3)

It's a 10x6. Gonna use that for the first hand launch till I get used to it. Have two APC 9x8.5 pylon prop's to go on later. I wan't a good combination of speed and vertical.

MJD

My Feedback: (1)

That's actually what I figured you were doing, but I had to ask. Same deal as test flying it with a West .50 on a 9-6 (equivalent test flight prop for the higher timed West).

It will be interesting to see the top end on this with the Jett on the 9x8.5. My SWAG is 160.

PAK26499

My Feedback: (3)

Anyone ever dealt with inaccurate readings from the $22 tower hobbies tach's?

Reason I ask is when I originally broke in the SJ .50 with Omega 15% I could not get it to peak past 16,100 RPM with the 10x6 once the initial richer run in was complete. ( I ran it for over 30 mins with a 9x6 APC @ 17,000 BTW on the stand per the instructions.) I figured it was just bad gas and ordered some Powermaster 15%. Anyways, now that I have the powermaster I fired it back up and once again it wont peak past 16,000 or so even after changing out glow plugs. I still dont want to push it too hard as I know it is new

The engine idles smooth as glass, transitions perfectly, and sounds like it is running strong somewhere around 17,000 or so and has no symptoms of anything wrong, yet the tach only indicates 16,000-16,100 and I know they chart for at least 17,000. Maybe i'm overthinking it and need to give it more time.......

(When I place the tach against a fluorescent light it shows correct calibration of 3,600 RPM for 2 blade.)

combatpigg

My Feedback: (3)

Don't fret about rpm figures with a 10x6 prop. A 10x6 prop will do nothing
but get you nowhere when it comes to going fast. A 10x6 prop is like using training wheels on a kid's first bicycle...just make sure you don't let the engine over heat.
Jett might still have direct support at the engine forum for prop recommendations / airframe combinations..

PAK26499

My Feedback: (3)

Put on a 9x7 and did a brief 30 sec run before the neighbors started yelling at me. 17,500+ while still very rich. Solution solved. Im thinking they may of tweaked the timing a bit since I did specify it was going on a Magnum???

Thanks for the input.

airraptor

My Feedback: (66)

not all APC 10x7 props are the same. The ones that jett used to post numbers on web site dont reflect the newer APC props as they seem to take 200-400 off the older props.

17,000+ on a 9x8 APC is a good number and should put this plane around 140-150

PAK26499

My Feedback: (3)

Flew the Magnum today with SJ .50 and bubbless tank added.....all went well. Ran a 10x5 for the first launch and flew right out of my hand (Peaked 17,500 BTW with the 10x5. Could only get 16,000 or so with the 10x6).

I was completely by myself so I had the transmitter in one hand and the plane in the other. Did the overhead method I was used to with that old modified Duraplane I have.

Switched to a 9x8 for the second go and let er rip. Again the launch went straight ahead like it was on rails. Did a couple high speed passes and straight up vertical's. I estimate in the 140-150 MPH range. So far I am pleased with it and as the engine gets more time gonna start pushing it some more. Gonna have to do some lateral balancing as it is dipping a wing a bit in the loops.

What was most impressive to me was how stable it is in slow flight. Will make landings a little less hairy as my landing spot is pretty tight.

The highlight was the very slow high alpha pass I did courtesy of the added rudder followed by a vertical climb. Even with the 9x8 it accellerated rapidly straight up till it was almost out of sight. Gonna try the APC pylon props I have next go around.

Think im gonna like this thing.......

Strykaas

Where did you set the cg at btw ?

PAK26499

My Feedback: (3)

160 MM. Works great....

Strykaas

Thx !

ledd4u

My Feedback: (23)

always wanted one of those. Do they still sell them?

PAK26499

My Feedback: (3)

http://www.westonuk.co.uk/westonuk2_103.htm