NX4 OS55 upgrade

[LegndarySaiyan]

Does anyone know if the y.s. engines work with this? I can't think of a reason they wouldn't. I have a 56 and I'm thinking about stretching mine with the 50 mount kit.

[Glenn Goodlett]

If the head is even 1 mm taller, it will not fit.

I was hoping a YS 60 would fit but I don't think it will.

The specs for the kit say OS 50 or 55.

However, I fell sure you could force it to fit with some extra cutting and grinding.

[LegndarySaiyan]

The cylinder head clearance is the issue? I think the ys head is a bit shorter than the os. I have an old os 50 hyper if the ys doesn't fit so I think I'm going to give it a shot in the near future. If the ys doesn't fit I'll just use my 50.

[Glenn Goodlett]

Problem is clearance everywhere. I had to cut the fan shroud at the carb as well. I think that was due to running the 20 tooth pinion and moving the motor as far forward as it would go.

[SlezY83]

If you have the YS engine, some photos here and in user manual for OS MAX engines (50 and 55 as well) are dimensions; you can measure it and will see...

Even though, I would say, that the engine would fit there (maybe some minor modification like cutting or work with very small rasper...).

If you realize it, let us know, whether it fits there and what modification are needed...

[LegndarySaiyan]

I ordered the 50 conversion kit, 475 X4 tail parts, 480 blades, and fresh bearings for my 56. I'll will see how it goes and report back. I have no problem using a Dremel if necessary.

[ChuckL]

Here's the thread from the first guy that I'm aware of that put a 50 in this bird he used a YS50.

https://www.helifreak.com/showthread.php?t=665916

[SlezY83]

Well, here is what I mentioned about one week ago:
Kit for 50 Type Engine
http://www.fast-lad.co.uk/store/prod...ducts_id=35348

[Glenn Goodlett]

Originally Posted by LegndarySaiyan

I ordered the 50 conversion kit, 475 X4 tail parts, 480 blades, and fresh bearings for my 56. I'll will see how it goes and report back. I have no problem using a Dremel if necessary.

Thanks for that post. I didn't even know that 475 was an option. It seems like a better option than the X5 tail since it will be less tail heavy. I ordered the same.

Do you think the 20 tooth pinion is too tall of a ratio for this set-up? Seems like a headspeed of 3000 would put you in the sweet spot of the pipe, but dam that's scary fast.

[LegndarySaiyan]

I'm running the stock pinion (19t?) with 465 blades on the 37 currently. Can't remember my headspeed but I would guess I set 2700. I'm sticking with that for now. I agree though, the x5 boom seems to require added weight to balance and I'd like to avoid that. I may get a chance to start working on my conversion this weekend if parts show up in time.

[godjc]

I,

Have you mount a washer on the crankshaft before the fan hub ?

With my fan touch the fan Shroud.

Jc

[Glenn Goodlett]

Originally Posted by godjc

I,

Have you mount a washer on the crankshaft before the fan hub ?

With my fan touch the fan Shroud.

Jc

Yes, I have a washer between the front bearing and the fan hub.

[Specter_03]

Hello,
can you tell me is we can stay with the original gear (17T?) or must a supperior?

Thank you

[Glenn Goodlett]

Yes, you can stay with the original 17 tooth pinion gear. I am just experimenting with different ratios.

[Specter_03]

Ok thank you, good after a little calculation quickly, I may have only 2450RPM with 17T is not ennorme I think.
the problem is to put the 19T option, you have any other option ... it is quickly climbing the final bill ...

and sorry for my English, it's google translate

[godjc]

I,

I have mount a TT53 and 20T upgrade.

http://www.france-helico.com/topic/2...grade-os-5055/

regards

Jc

[LegndarySaiyan]

Got my nx4 all together today. Ys56 fit fine. I cut the fan shroud quite a bit to clear the carb and head. Also had to add shims between the the bottom carbon plate and frame braces to clear the head but other than that everything went smooth.

[LegndarySaiyan]

Here's some pics.

[Glenn Goodlett]

Looks good!

I'm impressed that you could keep the tail servo on the right side, with the OS 55 Hzr you cannot due to the regulator.

I flew mine today with the 480 mm mains and 80 mm tail blades. It flew fantastic at 2850 with plenty of pop and it autos much better now. I think it could take a little more pitch or a little more aggressive blade as it is unbogable now.

I bet with the stock (17 tooth) pinion, it would have no problem swinging 500 mm blades. However, I would hate to add more tail boom to an already tail heavy machine. I wonder if there is any chance that 500 mm blades would fit the 475 tail boom?

[LegndarySaiyan]

I hear you there. Mine is a little tail heavy now with the 475 boom and 480 mains. I do have a set of 500 mains I can try later on after I get the maiden and tuning out of the way. I was eye balling it earlier and there's a chance they could clear. I'm curious about your hs though. My math put my engine at 18,300 with a hs of 2600 which is a 100 rpm drop from what I ran with the 37. Seems to be the sweet spot on a 17t. I would love to keep my 2700 but it seems I'm above the practical rpm of the bigger engine.