Pocketbike Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
89 Posts
Discussion Starter · #1 ·
I'm new to the PB stuff, but have been flying giant scale RC planes for years.

Specifically, Pylon racing airplanes.

Last year I wrapped up a project that might be helpful to some. I have a plane called a Sundowner. It's got an 80" wingspan and uses a 2.10 cid rotary valve single cylinder 2S made by a company called Moki.

Engine is around 35cc and rated at 5hp on 10% nitromethane glow fuel.

The prop I wanted was a 16"x16 pitch. The stock engine was able to turn it to a peak ground RPM of 7400.

After extensive modification (new head, a water "coil", radiator, full wave tuned pipe, new RING (the point of this) and some other stuff), I was able to get the same prop up to 11,500rpm on the ground. In the air its unloading prolly another 900-1200 rpm for a peak of 12,700.

That's a theoretical ground speed of over 190mph! The plane does nowhere near that due to drag on the airframe, but it's safe to say that it definitely hauls the mail. It's been radar gunned at over 150mph during straight and level flight. This is a 80mph increase over the stock engine.

Not too shabby. :D


Frank Bowman is an old man that lives down in New Mexico. Frank is a sharp ol cat and machines scratch built piston rings for RC engines. His rings are legendary in the gas/big displacement RC airplane community. He made me a ring for the Moki engine and it responded really, really well.



You can find Frank by just Google foo-ing his name along with piston ring.

His stuff is affordable and it WORKS!

Maybe this will help someone with an engine project.


Here's a YouTube of the Plane/Engine:

http://www.youtube.com/watch?v=MWDosPup5L0


 

·
Banned
Joined
·
21,742 Posts
It definately will but whats the cost for one of his ring sets?

does your plane have a CDI ignition or is it a solid state coil to flywheel ignition?
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #3 ·
Rings are cheap. Usually no more than $20/$30 bucks.

Uses a CDI. Auto retard on startup and full crank goes to around 28BTDC.
 

·
Banned
Joined
·
21,742 Posts
Rings are cheap. Usually no more than $20/$30 bucks.

Uses a CDI. Auto retard on startup and full crank goes to around 28BTDC.
Nice price..right in there with the quality Wiseco rings I use now...the cheap chinese rings turn to rubber when heated............I wonder if he'll chop me a discount if I order 10 sets of 44mm and 5 sets of 40mm
 

·
Banned
Joined
·
24,145 Posts
I ran 11.5 to 1 Wiseco pistons and rings in my Kawasaki Pro Stock drag bike, good stuff.
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #7 · (Edited)
Here's another little offering for the Gawds of Speed. (Burt Monroe is my hero!)

NIC Industries in White City Oregon makes a product called "CeraKote." They started this stuff with firearms coatings. We use a lot of it in my shop for customer guns.

338 Allen Magnum Express I built coated in "sniper grey" cerakote:



50 BMG single shot. Another one of our builds"



M4/AR15 done up for 3 gun matches:



They also have a high temp coating division. "Piston coat" is supposed to be one of the new "wigit" coatings that they have. I've not used it yet, just ordered a bottle in fact.

If it's anything like their gun coatings, it'll be pretty bad ***. $35 bucks buys a 4oz sample size bottle. 4oz goes a long, long way. We use right around 40-50ml when coating all the metalwork on a typical bolt action rifle.

Might be worth trying on slugs/rings just to see if there's a performance increase.

Just prep your pieces, spray, and allow it to cure. There's two versions. One is an oven cure (500*F for two hours) and the other is air dry. Air dry needs to cure out for about 3 days.

Use either an airbrush or an HVLP touch up gun with either a .8 or 1.0mm tip.

Good stuff!

C.
 

·
French Fries N Cheese
Joined
·
1,174 Posts
I still find laminated wood give the best results as far as color goes...

Anyways, lets just say I would walk around the woods with the pink AR during moose season, they would see me coming from a mile away, LOL.

I'll take some pics of my 7mm Rugger 1 and my Sako 300WSM. The rugger is laminated green/blue, with full chrome barrel/scope. I've got a 15 power Night Illuminated Leupold VX-RH, full chrome aswell.. It's probably the most immaculate piece in my collection, sighted dead on at 200 yards.

the 300 WSM is just a freaking brute.... Deffinately more punch than 300 Win Mag. I was shooting through quarter inch Carbon Steel at 900 yards with it not too long ago... Also has a 15 power VX-RH, except it's gunmetal grey. 20 rounds and your shoulder is black & blue. LOL.

my most fun weapon to use would have to bee my bolt action .177 cal. 0 recoil, 0 barrel heat, and you can operate the bolt with a single thumb. Grouping the size of a quarter at 200 Yards.
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #9 ·
Wait till you see our bedding jobs. I'll show it sometime.

Still waiting on the dern FED EX truck. . .


Ugh. . . .
 

·
French Fries N Cheese
Joined
·
1,174 Posts
Wait till you see our bedding jobs. I'll show it sometime.

Still waiting on the dern FED EX truck. . .


Ugh. . . .
Lol I cant ride either, 1 link blew off my chain, still waiting on my 5 foot strand of chain from SDscooters.... in the mean time I ordered 1 master link from fastenal... It should be at my shop tomorrow.
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #11 · (Edited)
Well Im stuck too. Bike showed up. Topped off the water per the manual I D/L'd and gassed it up. I used distilled water premixed with some "Water Wetter" from Redline.

Idle was ridiculously high. Fought with that for 20 minutes till I got it sorted out- the throttle cable was set way, way, way too tight and the slide wouldn't register to the idle screw. As a result it was stuck open.

Now the fun starts. . .

Prior to fixing the throttle issue I took the bike around the block for a test run. Definitely hauls the mail. Then it gets a little hot. I could hear the water bubbling in the res. I bring it back and let it cool off. I read the manual again and made sure I did it right. Fill, run for a minute or two, shut it down, raise the front wheel 30cm, burp the system by pulling the bent/bleeder screw, then fill with water again.

Button her back up and then there's this mysterious tuning issue as I piddle in my parking lot. Sounds great with it idling/running. Blip the throttle and the response is very, very snappy. Take it out to ride it again and it begins to miss/sputter when under load.

Sounds like a lean condition to me, ok. Just tune the carb a bit. Can't seem to shake it though no matter what I do.

A miss maybe?

Yesser. Water is weeping out the pump seal. Pulled the flywheel/mag and the seal is leaking. I'm assuming the miss is from water on the flywheel effin with the magneto.

All in all about $30 to fix but I'm a little annoyed at it.

So, long story short, I'm not real happy right now.

Bummed. Parts ordered and on the way. We'll see how this goes.
 

·
French Fries N Cheese
Joined
·
1,174 Posts
which bike??

Check the plug so we can see what the burn is like... if it's lean it'll be one crispy, grey,dry node... your looking for golden brown.

if it was air mail, condensation stuck inside the cooling system could have frozen, and damaged those seals... 2smoker wasn't meant to fly 36,000 feet in an unheated cargo bay.

Also, if it's your blata acting up, the Blata motors have internal pump problems often, so those are parts you want to have handy... Or go for a BZM kit...
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #13 ·
Well, pulled the motor and tore it down.

Heavy corrosion in the float bowl. That explains why the low end/idle circuit was AFU. The idle jet was completely plugged with fungus. Main jet wasn't much better.

Plug wire was loose in the coil mag. I snipped it and reattached it. Much better now.

Bearing for the sprocket shaft is shot. Rattles and shakes like a marble in a can. Replaced it as well.

Cylinder has some scoring. Luckily I have a Sunnen Hone so I'm going to put a fresh kiss on the bore.

Head is shifted to one side slightly. Makes for an uneven quench ring. I'll deal with that as well.

Corrosion was pretty heavy around the waterpump as well. I have some pretty exotic resin systems here that I use on tactical rifles for bedding the actions in the stock. I'll take some of it and fill/deck the pits so there's no leaks.

There was no Yamabond anywhere so I speculate there was some case weepage as well.

I have a gasket set and all the parts coming.

New bearings, seals, everything. If its worth doing, it's worth doing once.

Hopefully it'll get here tomorrow. Off to Whistler to pick up some bearings for the clutch and wheels.

I'm just going to go through everything.

Later,

C.
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #14 ·
which bike??

Check the plug so we can see what the burn is like... if it's lean it'll be one crispy, grey,dry node... your looking for golden brown.

if it was air mail, condensation stuck inside the cooling system could have frozen, and damaged those seals... 2smoker wasn't meant to fly 36,000 feet in an unheated cargo bay.

Also, if it's your blata acting up, the Blata motors have internal pump problems often, so those are parts you want to have handy... Or go for a BZM kit...

Engine is a touch rich according to the plug. Coffee brown.
 

·
Banned
Joined
·
21,742 Posts
Well, pulled the motor and tore it down.

Heavy corrosion in the float bowl. That explains why the low end/idle circuit was AFU. The idle jet was completely plugged with fungus. Main jet wasn't much better.

Plug wire was loose in the coil mag. I snipped it and reattached it. Much better now.

Bearing for the sprocket shaft is shot. Rattles and shakes like a marble in a can. Replaced it as well.

Cylinder has some scoring. Luckily I have a Sunnen Hone so I'm going to put a fresh kiss on the bore.

Head is shifted to one side slightly. Makes for an uneven quench ring. I'll deal with that as well.

Corrosion was pretty heavy around the waterpump as well. I have some pretty exotic resin systems here that I use on tactical rifles for bedding the actions in the stock. I'll take some of it and fill/deck the pits so there's no leaks.

There was no Yamabond anywhere so I speculate there was some case weepage as well.

I have a gasket set and all the parts coming.

New bearings, seals, everything. If its worth doing, it's worth doing once.

Hopefully it'll get here tomorrow. Off to Whistler to pick up some bearings for the clutch and wheels.

I'm just going to go through everything.

Later,

C.
Sounds good and like youre on your way....Watch out how much you hone the scratches out because if its too much youll get piston knock......The best thing about buying pistons in bulk is theyre all a lil different in the sizing...when i honed my 5 port cylinder with a lowely old caliper hone..Luckily for me I found a piston that would of been too tight for a regular bore......Good Luck....
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #17 ·
Its fixed! Lil phugger hauls the mail now too. The carb had a serious yeast infection down in the bowl. Crap all packed in/around the jets and the bleed screw for the bowl. Not it makes sense why the emulsion screw for the idle was cranked all the way shut.

This thing is a brute now! I also found a belt-well almost. Traxxis nitro 4 tech rc car uses the same pitch gilmer belt. Its just a pinch longer. If the right one doesn't show tommorow im debating on making and idler pulley. Cost of the belt was 7.50. That alone makes it almost worth it. I got my bearings/seals at whistler bearing. All new seals/bearings (american made too) cost me less than one belt from midsouth.

Im stoked. Set the quench to .5mm. Throttle is snappy and NO LEAKS! I buzzed one lap in my parking lot eventhough the pump isn't turning yet. Less than 20 seconds total. Powerband is very linear now. Its not grabby/unpredictable at all.

Pretty cool. Im a happy guy again. Plus I used all new ss fasteners so I know stuffs right now. Rear brake was binding up, fixed that too.

Pretty cool. If you haven't done so, SEAL your cases with yamabond! I used it on everything. Man did it make a difference. It actually takes effort to pull the starter now.

Sweet!

Gnite

C.
 

·
Banned
Joined
·
24,145 Posts
Way to Go! Get use to it, have to work on them alot, but it's worth it. Things vibrate loose, and stuff breaks,lol.
On the cylinder hone, or sanding the cylinder walls, I believe its cast alum w/ some kind of thin hard plating for the rings to seal on. Cam2 would know more about that, but its hard when you file it.
 

·
Banned
Joined
·
21,742 Posts
Its fixed! Lil phugger hauls the mail now too. The carb had a serious yeast infection down in the bowl. Crap all packed in/around the jets and the bleed screw for the bowl. Not it makes sense why the emulsion screw for the idle was cranked all the way shut.

This thing is a brute now! I also found a belt-well almost. Traxxis nitro 4 tech rc car uses the same pitch gilmer belt. Its just a pinch longer. If the right one doesn't show tommorow im debating on making and idler pulley. Cost of the belt was 7.50. That alone makes it almost worth it. I got my bearings/seals at whistler bearing. All new seals/bearings (american made too) cost me less than one belt from midsouth.

Im stoked. Set the quench to .5mm. Throttle is snappy and NO LEAKS! I buzzed one lap in my parking lot eventhough the pump isn't turning yet. Less than 20 seconds total. Powerband is very linear now. Its not grabby/unpredictable at all.

Pretty cool. Im a happy guy again. Plus I used all new ss fasteners so I know stuffs right now. Rear brake was binding up, fixed that too.

Pretty cool. If you haven't done so, SEAL your cases with yamabond! I used it on everything. Man did it make a difference. It actually takes effort to pull the starter now.

Sweet!

Gnite

C.
Nice job...........Look up ethanol stabilizers or the same thing will happen again...that bacteria happens when moisture creeps into the carb and the gastank...........I use CRC ethanol stabilizer.....It works.I hope you used loctite or safety wire on those fasteners...Its very much needed
 

·
Registered
Joined
·
89 Posts
Discussion Starter · #20 ·
46 tooth belt from Traxxis works just fine. I've put 4 tanks of fuel through it this afternoon.

Hauls the mail!

I'm not running pump gas. I jetted it for Q16 from VP. 6%oxygenated unleaded at 107octane.

Next is getting some fiberglass header wrap for the pipe. It's cookin my cinnamon ring :)

Seems to love it.
 
1 - 20 of 21 Posts
Top