Vortexgen
Posts: 397
Joined: 3/12/2003
From: Fortitude Valley, AUSTRALIA
Status: offline
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The Conversion Kit.
The kit contains the following?E
Longer Tail Pipe (anodized blue)
Longer Tail belt
Solid engine mounts (anodized blue)
Clutch shaft to suit 46-50 engine.
You will then need?E
46-50 size engine (glow plug and gasket)
46-50 size muffler, silencer, or tuned pipe
600mm Main Rotor Blades.
Let me begin by saying the caliber 30 was not designed with the thought of possibly installing a 50 size engine, so the stress, heat, power and performance factors of a 50 were not considered. As such, I would be concerned with simply slapping in a 50 on a standard caliber 30 to see how it goes.
The nature of the mod and upgrade would really only benefit people that can outfly their caliber 30 as it is. If you don?t understand this statement, you?re probably not ready just yet.
As an idea, my caliber 30 has the following upgrades already (from using the TT39) which make it more capable of handling the bigger engine. Im not trying to impress anyone but are trying to raise the point that you should have your caliber ready to handle the extra grunt with at least a few upgrades. Particularly the linkage system.
2.3mm linkages all round (not the standard kyosho ones)
QUICK UK Blade grips (metal 12mm blade grip, standard is 14mm)
QUICK UK cooling fan (metal)
QUICK UK mixing arms (metal)
Kyosho HG Swashplate (High grade ?Emetal)
Kyosho HG Aileron and elevator mixing levers (metal)
Kyosho HG Servo tray brace (prevents servo tray from flexing)
Kyosho HG Clutch Bell (metal)
Wide Skids
FT Canopy.
I also use a Governor GV1, with GY-401 on the calber.
Installation?E
Its relatively straight forward with a few exceptions.
The tail boom is easy and just replaces the original. The tail servo would then be mounted further aft on the tail boom, however, in my case, I ordered a longer tail control rod and kept the tail servo close to the frame. The boom is about 5 cm longer.
The blades are straight forward.
The engine is a bit tricky. The clutch shaft comes with 2 small screws that will be used to hold the fan on. They are very short. This became apparent because a 50 engine has a longer crankshaft, which when you screw the clutch shaft to, will protrude up into the area where the fan screws go. This means that the original fan screws cannot be used, and very short ones (supplied) have to be installed. Knowing the previous problems with fan screws coming loose, I decided to grind about 3mm off the 50 crankshaft and use longer screws. The end of the engine crank no longer interfered with the fan screws. (see pic below)
The glow plug has to be removed to get the engine installed ?Eit fouls on the forward skid as the engine is lifted into place.
The Left sideframe needs about 3mm shaved from it because the engine exhaust port is too close, and depending on the exhaust system will touch and melt the sideframe. (see pic below)
I used a Hatori silencer, and it was touching the fuel tank, so I had to make some aluminium spacers to push the pipe outboard further. The spacers were installed as if gaskets. Once again, it will depend on the exhaust system you choose, no doubt a tuned pipe and header combo would not suffer this problem.
EDIT 29th August - I now use a header and tuned pipe, no problems with spacing the silencer anymore. Be careful what you order, as hobby shops dont have headers specifically for a caliber 30 with a 50 engine, you may need further mods. -EDIT
Then it?s the usual engine and throttle linkage setup, and you?re ready to fly.
Flight?E
It has instant grunt! There is no question that the 50 engine in a caliber 30 is far more powerful than standard. The bigger blades make it more responsive, faster, and the 50 certainly keeps the power to the blades without problems.
The tail response is surprisingly even better (the caliber M50 has the same tail rotor diameter and gear ratio), I had to adjust my gyro gain up a bit, and piro rates were wild. Inverted acceleration, tick tocks and flips can be performed almost endlessly with good collective and cyclic management before noticing any power drop. Climbout is impressive, to say the least.
Autorotation is incredibly forgiving, in fact I oversped the rotor a number of times. You can auto and take off to about 2.5 feet then land again before the inertia is gone.
Downside?E
I used to get 11 min flight times with the TT39, now I get about 8.5 mins. I?m using the OS50Sx-H. (flight times calculated with the GV1 on and maintaining constant rpm from start to finish, obviously practicing autos or a normal throttle curve will extend the flight times)
The engine, engine mounts, sideframes, and everything nearby get very HOT which concerns me. I have added more cooling holes in the FT canopy (standard canopy is probably ok with its massive inlet), richened the mixture up, and added a spoiler to catch the forward air and direct it to the engine head. Still I?m experiencing high engine temps. I use 23% nitro, but may switch to 30% for more cooling. I now fly the 8-9 minutes then let it cool for about 5 before flying again.
EDIT 29th August - Cooling is no longer an issue, probably just new tight engine getting hot in its limited space. Now after 5 or so gallons, I dont think its a major concern, but would still check the temp periodically. I have gone to 30%, but the last gallon of 23% was not getting the engine that hot anyway, Ill go back to 23% after this 4 gallon drum of 30% as its cheaper. EDIT
The mechanics so far ( after 1.5 gallons) seem to handle the added power and stress ok.
I did destroy a clutch liner with the added power, from doing a power recovery (after auto). The power recovery was necessary because I was running on and the heli just didn?t want to come down out of ground affect! It drifted off the end of the flight area so I powered out. I believe the instant feeding in power destroyed the clutch liner. The liner was however, very worn, and may have only lasted a few more flight with the TT39 anyway.
I will continue to monitor the clutch liner, and see how my one way bearing handles the power. (its still original)
In conclusion, I don?t want to go back to the TT39, and if the caliber continues to withstand the added power, I can?t see a need to.
It?s definitely more powerful, more responsive, more forgiving, and yet more stable, and still a cheap platform to practice, practice, practice without the worry or high expense of destroying a 60-90 size machine. (been there-done that!)
here are the photos, starting with the simple kit. It retails for 9000 Yen, which is currently about $75 US.
< Message edited by RCadmin -- 9/11/2003 8:47:43 PM >
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All Forums >> RC Helicopters >> Kyosho Helicopters >> Caliber 30. 46-50 Engine conversion review. 
Caliber 30. 46-50 Engine conversion review. - 
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