600 Converting a Vibe 50 to a Vibe 50 BIG block !! with OS 91 engine

coolgabsi

coolgabsi

Super Mod & DEAL KING!
So , as you guys have seen in my signiature, one of the three helis I have is a VIBE 50. IT is a heli made by JR. JR made some bad birds (esp in the 600 nitro class) but then they copied ther JR VIBE 90 design to make a 50 and it was extremely sucessful. And then they copied Vibe 50 deisng to deisng Vibe 90 SG .. haha.. When it came out , it was one of the best nitro 600 helis in the market. The heli inherently is reviewed to fly on rails, and rightly so, man it tracks .. I can let push my sticks one way and draw a straight line.. it WILL FOLLOW! its a freaking train.. Its a bit heavier than its counterparts like Aling TREX 600 and Miniature Furion 50, Velocity 50 (outrage) etc, but it is quality bird. It was all the hoot when it came out , and Curtis youngblood then was a JR team pilot and he flew and tested all its prototypes.

Thats the history..

So, people who have Vibes love them to death. and ofcourse, who doesnt want more POWER!! HAHA.. so I researched and found someone had tried to stuff a YS91 in the Vibe before sucessfully. and they loved the power.. Now obviously the 90 engine drinks fuel, but heck if I cna get 6 moinuites of pure power.. HEY !! Thats good. The mod they had done was keeping the same gear ratio of 8.7 on the drive train.. which I will address later.

So the modding is simple.. I should say Simpler (or tony will kill me :D) .. So The equipment needed:

1) OS 91 HZ engine (DUH lol .. or any 90 size engine.. they make them pretty standard in dimensions.. )

2) Vibe 90 (NOT VIBE Scott Gray or SG .. ) engine mount .. as I explained above, there are tow Vibe 90 variants.. The engine mount you need comes from the Vibe 90 (V9) not Vibe 90SG (VSG)..

http://www.horizonhobby.com/products/engine-mount-v9-JRP996075

3) A Vibe 50 fan hub, and collets. (you can use the one that you already have.. or get another one.. )

4) 11T pinion from Vibe 90.

THATS IT!!!!!!!!!!

So mod:

The engine crankshaft is longer than a 50 size engine .. so it needs to be shortened by approximately 3mm.

The fan hub : the inner diameter of the hub is meant for a 50 size engine. The Fan hub hole needs to be drilled bigger.. This needs to be done VERY carefully as this hub is rotating 16000RPM.. and if the hole is not straight, the heli will eventually shake it self apart.

Different configs call for different washer config.. For example, an OS engine needs only one Prop washer, while Vibe manual calls for two in YS. Play with that, to see what fits best for your engine. I have a prop washer in my mine, and that makes the prop nut screw on the hub just enough so it had a good loctite hold on it. (LOCTITE is what holds your hub to the puller, the screw and threads by themselves arent enough.. )

After that is all done, mount the engine on the new 90 engine mount, install the clutch on it, and stick it in the clutch bell. Line it up and mark holes so the engine mount can be mounted square on the body. .The engine mount will need to marked with the mounting points, and that can be a bit tricky.. as you might have to play with that to get the right hole config.. Mine had to be done in a way that the holes were oval as they didnt quite coincide with the stock holes but were half way there..

Once the holes are marked , the mount will need to be centerpunched. through and through .. so the screws can go through and hold the mount..

OK so the gear ratio.. the Vibe 50 comes with a 10T pinion and a 87T main gear making it a gear ratio of 8.7. GREAT TORQUE for a 50 engine, but a bit too much for a 90.. It wont have the rpm I desire, and will probably end up stripping my main gear as the OS 91 engine makes about double the amount of torque a 50 would. The first mod that was done ran with the stock drive train and they had the engine basically screaming at 17000++ rpm .. the practical rpm of the engine is 16000 for OS and 17000 for YS. They never reported a faliure, but I wasnt confortable enough to run the engine that high rpm or 1700-1800 headspeed on the head ..

OS 91 HZ is rated at maximum power at 15000 RPM and maximum practical rpm 16000 RPM

15000/8.7 = 1724 power band
16000/8.7 = 1839 MAX


So now we install the 11T pinion.. That will make the gear ratio 87(main gear) / 11t pinion = 7.909

15000/7.9 = 1898~~~ 1900rpm power band
16000/7.9 = 2025 ~~~ max

BIG difference.

So I can essentially run the engine at 1900-2000-2100 rpm on Normal - ID1 -- ID2 . Why higher.. cause the head rpm drops when load is applied, so we try to run higher than powerband so when rpm drops it falls into power band and makes continous sweet sweet power.. :D

so that said.. we need the 11t pinion installed.. The pinion installation ::::::::::::::::::::::::::::::::::::::::::::::::::::: (TONY ADDS THIS )


Once pinion is installed on the clutch bell, mount the engine, and you will notice that the backplate of the 90 sticks lower than the bottom plate. So, what you would do, is just carve out the bottom plate shape from the bottom plate, and mount on the bottom plate.


Hook it all up, get the governor set, make sure the new gear ratio is in there and throttle linkage is set right.. and thats it



So did I do all this myself.. (LOL) NO!! I am not a good machinist and not to mention dont have a shop as I live in apartments. So TONY came to my rescue.. All the work done above was dont by Tony.. He machined it all, did all the painstaking installation and modifications and MAN he has done a GREAT JOB! I coudnt have done it without his help. All the KUDOS go to him for making this possible. I just paid for the parts, boxed it up and shipped it to him :D and told him basically what needed to happen. and magic happened there in the middle HAHAHAH..and couple weeks later I had my bird back :D :D :D


SO here it is all installed. I will ask if tont has some more pics of him doing any of this work. I can post the final product ..

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photo 1.jpg

Tell you what.. the MUFFLER LOOKS HUGE on this heli !! and man ! the heli looks sweet! :D cant wait to maiden it!

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X

xokia

Active Member
That thing should scream with all that torque. Congrats complaining about 6 min is kinda snobby LOL hahahaha
I get 6 min on my trex 700 and am very happy to get that lol

My guess is you will get longer run time then you think you will because that motor will not need to work as hard. I'm kinda wondering if it will ever come up to to temp. Maybe run a hotter glow plug? You'll probably have to play with that and monitor temps and see what works best.
 
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Tony

Tony

Staff member
Unfortunately, I didn't take any pictures or video of this swap, even though I wanted to. I was so friggin busy that weekend and needed to get it done and out of my house lmao. Just too many projects, know what I mean?

The modifications that are needed for this upgrade are minor, but take a LOT of time. It took me about 6 hours to get everything aligned perfectly and to finish all of the machining. The fan/clutch hub that bolts to the crankshaft was the easiest part. Just measure the crank, find a drill bit the exact same size, or one size larger, put it on the drill press and have at it. It took me all of about 2 minutes to do the hub.

The crank needs to be shortened on these because of the starter shaft. So, I put the nut on with the fan hub, counted the threads, then grabbed the cut off wheel. Yes, I put the engine in a bag lmao. However, I screwed up here and forgot to put the washer under the nut, but did have it under the cone on the crank, so I actually cut it 1mm too short. But, all but half a thread is on the crank with the nut. Not something that I would worry about. It will hold lol. Cutting the crank is easy as pie. Just mark it, and cut it, then grind the edges, remove the nut that you had already put on and your done. The reason you put the nut on and then cut is when you take the nut off, any threads that may have been damaged will be repaired upon removal. Simple.

I had talked to Gaba about the pinion on this thing and just looking at the one that was currently installed in the frame, shouldn't be an issue. Then I removed it from the frame.... ISSUE!!!!!!

The new 11T pinion was about 4mm longer than the stock pinion. Not a problem you say? It pushed the clutch bell down too far and NOTHING would line up. So, the pinion had to be made shorter.

So lets set the view for you guys. There are two sides to the pinion, one has threads to screw into the clutch bell and the other side is smooth to slide up into a bearing. Great, you can picture that. I had to remove 4mm of the teeth on the smooth side, but to do this, I had to chuck it up in the threaded side. I was very worried about doing this since I don't have a lathe and thought I would jack up the threads. Ah well, lets just chuck it up in my drill press! And that is what I did. I chucked it up in there, grabbed a fine toothed file, and let the shavings fly. It took me about an hour to get this thing perfect. I was taking about a thousandth of an inch off at a time, then checking it.

Each time I would check it, I would take it out of the drill press, screw it into the clutch, stick the smooth end up into a bearing to check the diameter, then install it in the frame. Once there, I would install the engine to check and make sure everything was lining up. Once things looked great, it was time to install everything in the helicopter. That is when I noticed the slight gap from the pinion to the bearing. Dammit, now the overall length was too long. So, I chucked it up again, and ground away about 2mm of material so that the pinion wasn't hitting the small bearing on the other side of the bearing that holds the pinion. Once that was done, it was just a matter if installing everything.

I will say this about the whole process, it's time consuming. The most time consuming part, no, not the machining, it was making the holes line up. When I started this, I thought the engine mount was threaded like it is on the Align 600N, but it's not, it's a straight through bolt. And had I known this (had I not been so friggin tired lol), I would have just stuck a drill bit down through the engine mount and BOOM, perfect holes. but no, I had to do this with a micro file. Not fun and my lungs told me about it later. Lining up the holes for the engine mount and the lower plate was by far the hardest thing to do on this. But, it's done.

It was a fun project, and from what Gaba says, there is a kit out there to put a 90 in my 600... hehe. Yeah, just a pipe dream right now.

All that we are waiting for now, is the maiden flight to see if this thing actually will fly.
 
Tony

Tony

Staff member
He told me in a text that he was too skeerd to take it up in the air. It's too much power for him :biggrin1:

And the RCH 600N proved that you can have a crapload of smoke, and still be very lean lmao.

What the hell happened to the "Rc-" on teh tail? All is says now is "Help", which I guess is what the helicopter is saying after this conversion hahahaha.
 
Adam

Adam

Active Member
Proper way to turn off the engine....... I have been wondering this as of now i pinch the fuel line is this correct
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
Yep that works fine.. Been doing it fit a while .. Also bringing throttle trim down works well too...

Nothing wrong about all that. Don't go reading too much. It's an almost nitro vs electric discussion haha

Believe me!! :)
 
Tony

Tony

Staff member
As stated, there are two ways for planes and heli's, and one more for cars/trucks. For planes and heli's, I use the throttle cut which lowers the throttle all the way and closes the carburetor. However, this can suck a LOT of fuel into the engine causing it to flood on the next start, but usually not. Pinching the fuel line also works. But as much fuel as these run, ti takes a while. Your truck should run for 3 seconds, no more no less when you pinch the fuel line. This also is an indication of your bottom end. Then, on cars/trucks, you can also touch teh flywheel and stop the motor. This is the way I ALWAYS killed my nitro car and truck. I just used my shoe since there was a hole for a starter box on the bottom, but this is a little harder on a tmaxx. Hope this helps.

Sorry for the jack, couldn't resist. Thought you finally put this heli in the air. Disappointed...
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
I am too. Tried hard to turn the engine with the old artery. New charged battery came out hot and soft . I tried it last night. I might just try to get the glow plug out and see if there is any fuel in there.

But after that. I am waiting for the battery I ordered from amain hobbies "electron" pack

A little frustrated too.. :/ helidirect order got "delivered" according to usps. But I didn't see nothing. I had ordered frame sides and stuff for the warp there

So warp setup will have to wait too .. Haha
 
Tony

Tony

Staff member
At least you are not being held off from flying because of wasps. I was ready to fly today, all 3 birds, and right before I went outside, they started swarming really bad. I decided to just hold off and fly later lol. Not sure when though.
 
murankar

murankar

Staff member
Sounds massive and boy that first spool up looked shaky. I hope you get the kinks worked out this will be a great flying machine.
 
Tony

Tony

Staff member
The wife said the same thing about the spool up. As I told her, I'm pretty sure it was just the blades not being straight.
 
Tony

Tony

Staff member
Yup, it happens on the first spool up of all birds. I saw it quite often on the live feed from Heli Masters when they sat their heli's down. Spooled them up just enough to straighten the blades and position the heli, then it was time for smack lol.
 
coolgabsi

coolgabsi

Super Mod & DEAL KING!
Didn't video it


Governor kept acting up .. Had the laptop so turned it off and went to basics ... Throttle curves and started the tune process

At stock mid and 1 3/4th high . I already have more punch than a 50 lol
 
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