OS -160 conversion
 

I finally got around to doing the conversion on one of my OS-160 FX engines, I am still waiting for the IGN to hit so I can't add the magnet and time it, but I think the rest is finished. The parts was some leftover materials I had on hand, Alum & delrin. I also went with the 1/4-32 plug for now I can always change it later if need be. The carb is from Davesmotors it is a WT-499 11.1 MM bore. I modified the stock hub for the magnet and put the pulse hole in the side and not at the rear like some I have seen.
I would like to thank w8ye for his input on this project the man knows his walbro carbs and much more.
If they will load here is what I have so far.
P.S. Just how does one turn the inlet fuel barb W/O breaking it off?

RE: OS -160 conversion
 

pinchers

RE: OS -160 conversion
 

The fuel inlet has a brass barb inside.

If you try to do anything with the fuel nipple it will break off leaving the little brass stub sticking out.

So the usual proceedure is to break it off and pull out the stub with pliers

You can get new ones either plastic or steel from Horizon, Bennett, or several other places.

The new one taps in with a small hammer

http://www.horizonhobby.com/Products...ProdID=ZEN6275

http://www.bennettbuilt.com/page2.htm

RE: OS -160 conversion
 

Richard if you are careful they can be turned with pliers as mentioned above, I have done it. Also if it does break it is easy to change. I keep a couple of the metal ones on hand in my parts bin. Btw nice job on the conversion. It looks real good.

RE: OS -160 conversion
 

What oil ratio are you going to use with this converson? Thanks Capt,n

RE: OS -160 conversion
 

Thanks guys , I think a 20-1 oil mix will be fine. still alot less than glow fuel.

RE: OS -160 conversion
 

Very nice work as usual Richard which brings back recent memories of your DLE back plate, but I have one observation. I know that you hardly ever do anything without thinking it all through, but why locate the pulse line so close to the engine mounting lug?

Karol

RE: OS -160 conversion
 

Hi Karolh, thank you.
I have done this type of a pulse set up for many glow engine useing a pump or regulator, Only I sunk it in some to make sure it was nice and flat for a good seal and to also prevent it from being knocked off in case of a crash. It won't weaken the mounting lugs and will clear the mount ok. I get a nice strong rush of air each time I turn the engine over by hand where it is at, so I think it should be fine
I originally was going to put it in the rear on one of the top bolts, but I didn't have the neccesary hardware on hand to do so, and to make it is not feasible for what they cost.
BTW that side of the carb is getting rather busy with the pulse, Gas, and throttle hookup on it but all will clear now so things should be good, however I am still thinking about a different throttle arm, that one is to long and sticks out a mile and it would be less work to change it than to mod the one thats there now.
I was able to turn the fuel fitting but it took alot of pressure with pliers, I will get a all metal one headed my way in case of leaks.
The throttle hookup with the exsisting arm on the other side was almost impossible to make work in its original configuration and be a pull throttle, and a push throttle I don't care for on a spring loaded carb such as a Walbro.

RE: OS -160 conversion
 

Yes it takes lots of pressure to get it moving. I used some rubber on the pliers so I wouldn't chew it up.

RE: OS -160 conversion
 

Excellent.

Karol

RE: OS -160 conversion
 

I love the ping ping sound my converted OS 160 makes around idle. It has an all around nice handling quality from starting to in the air performance.

RE: OS -160 conversion
 

Bob it was your conversion that Ralph did for you that made me decide to make one of my own. I have 3 of the 160's while
the 160 sips glow fuel for it's size I can only imagine what it will do on gas, What really got my attention was your statement about how reliable the engine is now on gas was the deciding factor. I know I will lose a little power but the plane it is going in never needed all of the power of the 160 to start with.
As soon as the IGN hits i'll be doing some bench runs with different props to see where I stand on that end. The weather here is trying to break so maybe I can even get a few flights in.
Who knows if this works out well I just may convert them all over to gas.

RE: OS -160 conversion
 

I look forward to your results. I am extremely curious as to how it will perform.

RE: OS -160 conversion
 

Your OS looks brand new compared to mine. I follow Ralph's advice and run 10:1 oil. I have no doubt yours will please you with one tiny caveat: it is kind of 'snappy' so wear glove. I do not know if that is due to mine having the CM6 plug or not. BTW, I bought a muffler for a G62 from rcextremepower. It fits fine and is much lighter than the original OS muffler.

RE: OS -160 conversion
 

Where can one obtain one of the magnets for the ignition?

RE: OS -160 conversion
 

I went to Radio Shack to get mine and all they had was some short ones and larger in dia than I wanted.
Here is where I got the ones I use on the engines I make, when I reorder I will get the 1/8"x1/4 and not the 3/32"X1/4 although they work fine it takes a little more figureing to allow for the Dia of the magnet when placing the hole in the correct place.
I went with the Neodymium Magents due to the strength prolly an over kill, a good rare earth magnet will work fine. Just remember to pass it under the hall sensor to see which way it needs to be installed, one way it will spark and one way it won't.

http://www.kjmagnetics.com/proddetai...prod=D36%2DN52

RE: OS -160 conversion
 

Hello Bob the timing could be the issue on the kickback did Ralph tell you where he happen to set yours? I plan on the standard 28 Degrees before TDC and adjust as necessary if needed.
The reason the engine looks new is because I just rebuilt it and soaked it in the old Crockpot for a few hours which really does a job of cleaning them up. While it was not all that dirty it still removed any castor buildup it had and came out looking almost new.
I can't tell you how many gallons of glow fuel that engine has thru it, but its alot. It needed bearings so why not go the whole nine and stick a new ring in at the same time.
Frank Bowman has them in stock and I have never been dissapointed with his work and this one is no difference. I think I got the bearings from Paul at RCbearings .com
A very lite kiss on the sunnen hone with some fine stones and I was off and gone.
A g-62 muffler eh never thought of that, i will keep it in mind if the Bisson I have gives me any issues. Thanks
Richard.

RE: OS -160 conversion
 

Hi guys
My Ign hit here today so I had a chance to run the 160, after a good warm up and some initial needle tweeking the engine would maintain a steady 1700 idle RPM with a high of 8850 -8900.
My set up was this
20-1 penzoil aircooled
88 octane pump gas
18x6 wide blade APC prop
Timing set at 28 Degrees BTDC.
Jtec exhaust diverter, not a muffler actually and made for a 108 to boot.
Elev. 4500 ASL
(Sorry no density altitude I forgot to call) But it was trying to rain*L*
New Bearings
New Bowman ring.
The engine before took a little to wind a 18x6 wide up, now its almost instant acts like a wood prop, the thing I really noticed is the smoothness of the engine, it seems as smooth as it was on glow fuel.
After some more run time and minor needle tweeking to get it dead on I really think I will enjoy this engine.
The low tick over at an idle is something to behold, I let it idle for a few mins while I walked outside and when I came back and nailed it, it was top RPM's instanally, no sag or flooded condition.
The low end needle is a little bit on the sensitive side but should be ok, the high adjust like a typical gas engine.
I did notice something, the ring looking thru the exhaust port is completly shiny now, I did get a little of the black splatters out of the exhaust which is normal, but the ring seated in very fast.
Compression feels good and it was one flip starts with no sign of a kickback.
All I can say is so far is that I am very pleased with the conversion and the amount of gas it used was considerablly less than glow fuel.
I have a xoar 18x8 laminated prop I may throw on it just to see what that will do, maybe to much we'll just have to try it and see. I have used a 16x10 APC pattern prop on it in the past with very good results, but I don't feel I will be able to run those props now again we'll just have to see.

Bob I can now understand what you have been saying all along, all I can say is what a little sweetheart of an engine with this set up.:D:D:D

RE: OS -160 conversion
 

My old 160 with a Pitts wrap around ran 8000 to 8200 depending on the day with 10% with a 18x8 Xoar. Let us know how it runs on gas when you get the chance Richard. Sure sounds sweet so far. :)

RE: OS -160 conversion
 

Doug what is your alitude up there?
I figured that I would loose alot by doing the conversion but so far It seems to be far less than what I had imagined.
I know it would spin a 16x10APC pattern prop at 93-9500 on 15 % glow fuel.

RE: OS -160 conversion
 

We are at 1500' at our flying field. The average tempature during flying season is 70 to 80 degrees.

RE: OS -160 conversion
 

Short runs won't be a problem but me thinks you might have rod bearing trouble at the crank end unless you run at least 16:1 fuel/oil ratio. My ST 90 will run several hours at 20:1 but eventually starts eating the rod bushing. It has over 50 hrs at 16:1 and the rod is holding up fine. Glad yours is up running.

RE: OS -160 conversion
 

Richard,

You were right about mine having excessive advance. Right after I read your previous post, I went and checked. Eyeballing it I think mine was around 40 degrees. I will reset it to 28. Thank you, sir.

RE: OS -160 conversion
 

Hi Jezmo
The oil content has me scratching my head a little bit also, my brain is about fried tonight . I did however pull off the bqck plate and have a look inside there was approx 1/2 teaspoon of oil or more just laying around in there. I will follow that advice and richen it up to 16-1
Oil is cheap as compaired to engines, besides its only another .8 ozs of oil per 1/2 gallon of gas useing that type of oil.
As well as the little engine runs and preforms I sure would hate to mess it up due to running it low on oil.
Thank you for your input.
Richard.

RE: OS -160 conversion
 

Good deal Bob, you are more than welcome, mine seems to like the 28 BTDC degrees just fine, Starts just like it did on glow fuel, a little prime and One flip and it's off to the races. But I am concerned with all the black I was getting out of the exhaust, I hope that it's just some minor ring wear, I did notice a slight drop in compression after it ran for a while when restarting it which is prolly the norm, but after things cooled off it seemed to be back up to the normal compression.