Barry Cazier

My Feedback: (17)

Is the new engine OSFXi shipped in the Hobbico Nextstar the same as an OS46FX? Is it more powerful? Does "i" mean injected? I don't see this engine available seperately. Is it only available with Nextstar. How does it compare to the new AX? Just curious.
Thanks,
Barry

MerlinL14

Barry, I cann't say I have heared of the .46 FXi. This may just be as honest as a missprint on their web site. I doubt that if it were injected that it would be offered with a trainer combo, something as radical as an Injected OS would have been BIG news and we would have had someone post about it.

MerlinL14

OK the FXi does exist, it isn't Injected though. I dont know what the difference is between the FXi and the FX but [link=http://www.hobbiconexstar.com/downloads/hcaa17-engine-manual.pdf]here[/link] is a link to the instruction manual.

britbrat

The FXi is a re-engineered FX, to incorporate cost-saving features from the AX. It has a 4-bolt head like the AX & it uses a plastice rear needle-valve assembly.

It starts easily & seems to produce about the same power as either the FX or the AX.

britbrat

Sorry, double post

duke

Plastic Needle valves used on FXi, La's and Ax break very easy. OS planned this to gain additional revenue from sale of these engines....sad.

MerlinL14

Thanks for the additional info . So the i in FXi stands for "inexpensive parts" LOL.

Barry Cazier

My Feedback: (17)

It just seems odd to me that they would introduce a new engine and have it be so similar to the existing offerings. I'm wondering if this is a hybrid engine. Maybe abc construction but with no bearings. I don't know. Just wondering. Also, I don't see this is available without the airplane.
Thanks,
Barry

britbrat

It has a ball-bearing crank -- think of it as an FX that looks like an AX & runs a little like an SF. It is as good as any current OS BB .46 offering in that size, & a ton better than a .46 LA.

roltech

The OS46AX MAX has four head bolts, not the OS46FXi The 46AX replaces the 46FX
I have both the AX sounds different due to PBOX muffler, I replace the motor on my Nextstar with the AX Max. they are both very good and yes expensive. still don't know what the (i) in FXi stands for.
roltech

roltech

The Oct. 2004 Model Airplane News has a review on the New O S Powerhouse 46AX
In that review indicates that it is replacing the 46FX with 46AX
roltech

Barry Cazier

My Feedback: (17)

So...to me the 46FXi sounds like a typical OS Engine, top of the line. I had a 46FX last year. I flew it in my Hobbico Superstar trainer. Man, it made that plane sing. When I started running it on 30%, it had so much power it was just comical. It would acelerate straight up. Is the FXi only available in the Nextstar? I haven't been able to see it in Tower catalog. Also, would you buy the i over the AX?
Thanks,
Barry

roltech

I don't think you can buy the FXi I have not seen it anywhere in any Hobby shops
But I must say I prefer the FXAX Max a lot more, I will get another one for my new RV - 4 40

boltster

I have FX and FXi the difference is needle valve which is plastic. Instead of buying metal one from OS I bought the cheaper one from TH 46 which is metal and works perfect and is cheaper.
Other than that I think they both produce same power. The AX is a little hotter engine and the ports are ball ground, the head has four bolts. I also bought and extra TH needle valve assemble and put it on a ST 45, no more stiches in my knuckle now, safe and work great.

roltech

What I meant after reading my own post. I prefer the AX over the FXi. It sounds better
and seem to have more power.
roltech

yellerchamp

My Feedback: (42)

If you put the muffler from the ax onto a fx you will gain rpm and they are near identical, the secret to the ax is the big p box muffler

Ace in the hole

My Feedback: (2)

I think I remember reading something once that said the "i" stands for improved. FXi = FX improved. If I remember right, the article said the main differences are that they changed the needle assembly mounting and maybe the timing so it was easier to tune. I'm trying to remember where I saw it, it might have been in a review of the nexstar. Anyway you can only get a FXi in a nexstar, some special deal hobbico made with OS.

I have a nexstar with a FXi and a hanger 9 T-34 mentor with an AX. Both are great running motors.

SBR_RV

first time ov heard of a 46FXi

Ecklund1

OK. I think my brother and I have it figured out. The "i" might mean intermediate. I have the NexStar w/46FXi and he has the 46FX. We did a side-by-side and came up with this:
The FXi BB motor has the 6 bolt head, square carb. and round muff. like the FX. But the separate plastic needle body like the AX and a head that appears to be like neither.
Maybe OS had a crate of motors not quite ready to be released as the AX and dealed them to Hobbico for a deal.

Jeff

sfsjkid

"i" for intermediate may be the most appropriate(?). I briefly compared part numbers in the manuals. FX and FXi share the same cylinder/piston assembly, piston pin, conrod and carb. The FXi and AX share the same front and rear bearings. All have different crankcase and crankshaft. I'll stop the comparison here since my eyes went cross-eyed reading the 3 manuals at the same time

w8ye

My Feedback: (16)

I've been around several FXi's and the head is very different from the straight FX head. They are 6 bolt. They have a AX style needle valve assembly except there is a limiter on it like on the Evolution engines.

I know the FXi doesn't seem as powerful as most FX's. If the Cylinder/piston have the same number, then the difference must be that funny looking head. It must give the FXi a lower compression ratio?

I recently rebuilt two OS 50 SX's. One had a dished piston from someone forcing it when hydro locked. It doesn't run near as fast as the one with a good piston. The owner didn't want to spend the extra money for a new piston. I made it work like it was. This damaged engine has a lower compression ratio than the good one.

Enjoy,

Jim

Tiroloco

My Feedback: (1)

The differences between the 46 fx and 46 fxi are the needle valve and the cilinder head of the 46 fxi is the same of the 46 LA.

Regards.

rcuser002

My Feedback: (12)

Friends,

They say pictures tell a thousand words so, here's my pictures in gratitude for finding this thread!!

and special thanks to boltster for the information regarding the T H replacement metal needle valve (for the fxi) that only costs $12 (free shipping) instead of the $28 that OS wants for the whole coverplate assembly from the 46FX.

I noticed bubbles in the fuel line going to the carb and wondered where it was coming from. Thank God for the problem being recognized on the ground--no dead sticks please!!

The plastic threads were totally stripped from engine vibration, fuel eating the plastic or just "plane" overall wear & tear.

Thanks for this thread-- I've learned a lot from it .....

Here are the differences:

root

95tequesta

My Feedback: (4)

This is directly off the Tower site. To answer the question one must go to the source. Going to the source will not give one the answers unless the answer has a definite questioned. One may not know the correct question therefore one must regress (in this technological, give it to me now era) and READ!



Engine: Pre-installed O.S. Max .46FXi (7.5cc) with high-speed
needle valve extender/limiter that limits the movement of the
high-speed needle to prevent engine from being run too lean,
engine is mounted on IsoSmooth Mount to isolate airframe and
radio gear from damaging vibration


One must also answer the question---does it matter? If one likes a particular item then use it. If one does not, then don't?

shussey

Where can I find the TH 46 needle valve?

Thx