modifications to an 049

modifications to an 049
View related threads: (in this forum | in all forums)

Logged in as Guest

Users viewing this topic: none

Printable Version

Meister Scale FW 190 D9 - RTF
Seller: 1958 cadillac
Details: $3,100.00 | 11/20/2008 | Classified Ad
We will rotate YOUR AD in this spot if you select "Forum Featured" when placing or editing your ad!

All Forums >> RC Airplanes >> "1/2 A" & "1/8 A" airplanes >> modifications to an 049

Page: [1] 2 3 4 next > >>

Login

Message

<< Older Topic Newer Topic >>

modifications to an 049 - 8/17/2007 4:31:11 AM

500 lb. koolaid man

Posts: 1052
Joined: 5/22/2006
From: Palm Harbor, FL, USA
Status: online

I'm wondering if there is any way, or any available guides, at least pictures of two specific mods to an .049: #1, homemade exhaust pipe, #2, a homemade carburetor to be used on a control line model.
This is where the inspiration came from, this guy made his own carb and pipe.
http://youtube.com/watch?v=zrgbUFCzt_g He has two other good videos of the engine too. Heck, this might even be the same engine from ebay, it looks very similar anyways.

here's the e-bay engine http://cgi.ebay.com/New-Cox-049-Sure-Start-1-2-A-Gas-Airplane-Engine_W0QQitemZ320148229375QQihZ011QQcategoryZ34055QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Posted are both a picture of my engine and the e-bay engine, the two candidates for the mods. Also, since I've decided to make this thread anyways, I gotta ask, my engine is nothing special or rare, rite? I got it for free from a neighbor a while ago and don't know it's history, all I do know is it's a fun engine

Thanks for the help.

_____________________________

I have too many projects already... but I always find more.

RE: modifications to an 049 - 8/17/2007 7:02:29 AM

burtcs

Posts: 456
Joined: 12/20/2004
From: Corvallis, OR, USA
Status: offline

500lb'er:

The second photo (ebuy auction) is a common COX Sure Start. My connection is too slow to download video - sorry. The tube is for choking, every thing is standard. As far as exhaust pipes go they're as close as you nearest swap meet (tatone). There used to be a guy that sold pipes for COX engines, he may still be around though I don't know is web adress. Some one else might.

regards - Steve B.

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 2:49:36 PM

500 lb. koolaid man

Posts: 1052
Joined: 5/22/2006
From: Palm Harbor, FL, USA
Status: online

Thanks for the info, burtcs.
-Do you know how people even hook up exhausts to these engines?
-Do you know if my engine is anything special?
-Is that a built in tank on the e-bay engine? Thanks for the info so far on that engine, you tout me a lot of things I didn't know

-I've been running my .049(only once or twice) with 20% car fuel. I know the manufacturers recommend "1/2A fuel" I now have a gallon of 15% plane fuel, will that be ok for the engine?
Ok, that's the last of my questions.

Thank you very much.

_____________________________

I have too many projects already... but I always find more.

(in reply to burtcs)

RE: modifications to an 049 - 8/17/2007 5:41:27 PM

gcb

Posts: 2472
Joined: 10/24/2002
From: Port Ewen, NY, USA
Status: offline

quote:

ORIGINAL: 500 lb. koolaid man

Thanks for the info, burtcs.
-Do you know how people even hook up exhausts to these engines?

The first I had with an enclosed exhaust was a "QZ". I think the cylinder was removed, the muffler put on, and the cylinder reinstalled. Some throttled versions had the cylinder machined and the throttle sleeve was installed by removing the cylinder, inserting the throttle sleeve, then reinstall the cylinder. The Tatone muffler came in two parts which were screwed together over the cylinder (without removal). All this is from memory so it may be a bit inaccurate.

quote:

-Do you know if my engine is anything special? Is that a built in tank on the e-bay engine? Thanks for the info so far on that engine, you tout me a lot of things I didn't know[

It appears to be a standard later model Babe Bee, before they went to the plastic backplate tank. The fill nipples (with the green tubing) extend only into the tank cavity. If flown inverted fuel will spill out a bit. Either nipple can be used to fill, the other will vent. Later models had one fill nipple, the other a small hole for venting.

quote:

-I've been running my .049(only once or twice) with 20% car fuel. I know the manufacturers recommend "1/2A fuel" I now have a gallon of 15% plane fuel, will that be ok for the engine?

Beware of car fuels. Some of them have very little lube because they are run at high RPM under light loads and do not need as much lube. The plane fuel may need some castor oil added because of the ball-socket on the upper end of the connecting rod. That area gets VERY hot if run lean and some synthetics will "flash" off and lose lubrication. It will run OK on 15% nitro. The oil is the questionable quantity.

quote:

Ok, that's the last of my questions.

Thank you very much.

WHEW!!

George

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 5:41:59 PM

500 lb. koolaid man

Posts: 1052
Joined: 5/22/2006
From: Palm Harbor, FL, USA
Status: online

I found out by more research that my engine is a Cox Babe Bee and also that the ebay engine requires an external fuel tank. I also found out that running 15% plane fuel is ok. Looks like I just answered most of my questions.

If I'm going to make a carb or an exhaust, I guess I'm going to have to be creative on this one.

burtcs, I'm confused by "the tube is for choking" on the e-bay engine. I thought the tube is for a fuel line, to supply fuel from a tank?

Thanks.

edit: Thank you very much for the info George!!! I just read your new post.

< Message edited by 500 lb. koolaid man -- 8/17/2007 5:45:17 PM >

_____________________________

I have too many projects already... but I always find more.

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 6:02:19 PM

gcb

Posts: 2472
Joined: 10/24/2002
From: Port Ewen, NY, USA
Status: offline

quote:

ORIGINAL: 500 lb. koolaid man
...I'm confused by "the tube is for choking" on the e-bay engine. I thought the tube is for a fuel line, to supply fuel from a tank?

Thanks.

edit: Thank you very much for the info George!!! I just read your new post.

The choke tube is the gray tube used also to support the needle valve. Earlier product engines did not have this. It makes it easier to put your finger over the tube and flip to pull fuel from the tank to the venturi. This is called "choking" the engine.

BTW, The plastic disk in the picture is supposed to be inserted over the thrust plate. The thrust plate must be hexagonal to match the plastic. Your thrust plate (where the prop fits) appears to be the type used on engines provided without a starter spring or one that uses the type spring that you pull into the prop to use, then it snaps back out of the way. I don't think your spring starter will work. Not to worry, you don't need the spring and you can just dislodge it from the cylinder and remove it. Most guys remove it anyway (including me).

George

Edit: Forgot to mention, the gray choke tube is for air. On the backplate opposite the needle valve is a nipple where the fuel line from the tank goes.

< Message edited by gcb -- 8/17/2007 6:07:19 PM >

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 6:21:30 PM

500 lb. koolaid man

Posts: 1052
Joined: 5/22/2006
From: Palm Harbor, FL, USA
Status: online

Thank you very much George, The help is very appreciated!

_____________________________

I have too many projects already... but I always find more.

(in reply to gcb)

RE: modifications to an 049 - 8/17/2007 6:30:05 PM

500 lb. koolaid man

Posts: 1052
Joined: 5/22/2006
From: Palm Harbor, FL, USA
Status: online

One more question, sorry,

I hope this really is the last one.

Is it possible to make a control line engine "idle" by making it too rich? I can't seem to find any info on this.

Thanks.

_____________________________

I have too many projects already... but I always find more.

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 7:03:21 PM

burtcs

Posts: 456
Joined: 12/20/2004
From: Corvallis, OR, USA
Status: offline

500lb'er:

I think about your only option here is to use a throttle sleeve. Norvel engines pulled it off, small engine, varible throttle and a muffler. COX never did it well, they did use a throttle sleeve which worked ok. This is a sleeve that fits around the cylinder and closes off the exhaust flow. A carb restricks gas flow coming in, the exhaust sleeve restricks flow going out. Ether way works. I don't know of any set up for an exhaust pipe.

A note: the idle on a small engine like your will be quite high. It's not like a car engine. When you drop below 7000 rpm, the thrust coming from the prop is NIL. So think 5-7K as the idle rpm.

The Tatone "pipe" was split and the two halves clamped around the cylinder. It was not tuned, just a pipe about an inch and a half long.

GCB gave you good anwsers, just add and once of caster oil to your car fuel. I run engines on 10% all the time but the fuel is fortifide with caster. For spot flying use 20-25% but 15% will work.

regards - Steve B.

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 7:25:03 PM

gcb

Posts: 2472
Joined: 10/24/2002
From: Port Ewen, NY, USA
Status: offline

quote:

ORIGINAL: 500 lb. koolaid man

One more question, sorry, I hope this really is the last one.

Is it possible to make a control line engine "idle" by making it too rich? I can't seem to find any info on this.

Thanks.

Speed Control 101:

Somewhat. The first attempts at speed control on glow engines was a two needle setup. There were several ways to set it up. One way switched needles. One was set rich, the other lean. I think the more popular way was to have one needle connected all the time with a lean setting, then one turned on and off with an air bleed to provide a rich setting.

Next came exhaust restrictors which had either a butterfly or a rolling baffle arrangement to restrict exhaust to slow it down. Its downside was that it caused the engine to heat up a lot.

Next was a flapper valve that would cover the intake to provide a partial choke and cause it to run rich. A hole in the flapper would provide air adjustment. Some engines started using combinations of the flapper and exhaust restriction.

Next came crude throttles of various types, usually coupled with an exhaust restrictor. Sometimes the exhaust restrictor was not used if a muffler was installed (mufflers were quite restrictive in those days).

Sometime during this period, the idle-bar glow plug came about to help keep the engine lit.

Improvements continued until we have throttles available that run well through the entire RPM range.

The chronology may be incorrect, but it is the way I encountered it...

George

(in reply to 500 lb. koolaid man)

RE: modifications to an 049 - 8/17/2007 8:02:44 PM

lz-23

Posts: 231
Joined: 6/3/2007
From: Chicago, IL, USA
Status: offline

Hi guys, I was wondering if there is a way to convert Sure Start to diesel? I know that there is a conversion kits for TeeDee's, but can't find anything that might work for Sure Start's.

(in reply to gcb)

RE: modifications to an 049 - 8/17/2007 8:33:48 PM

gcb

Posts: 2472
Joined: 10/24/2002
From: Port Ewen, NY, USA
Status: offline

The same diesel conversions that fit on a Tee Dee work on the Sure Start, BUT, diesel conversions to any Cox reedie requires a high performance crankshaft like the one sold by DDD. The reed valve engines are just not intended for diesel conversion. You can do a search on this web for discussions about it.

To that end, so far my only Cox conversion is a TD. I have an old version of the DDD crankshaft but have not yet used it. I understand they have improved it.

IMHO, if you want to run diesels, get diesels.

The Sure Start is a nice little engine when used as intended.

George

(in reply to lz-23)

RE: modifications to an 049 - 8/17/2007 8:57:19 PM

lz-23

Posts: 231
Joined: 6/3/2007
From: Chicago, IL, USA
Status: offline

Thanks a lot George! I'm going to stick with glow in this case. Can you share you opinion about TD to diesel conversion? How it behave? Is there any improvements/drawbacks? How is the power after this mod?
Thanks again!

(in reply to gcb)

RE: modifications to an 049 - 8/17/2007 9:39:39 PM

burtcs

Posts: 456
Joined: 12/20/2004
From: Corvallis, OR, USA
Status: offline

Iz-23:

IMHO a dieseled COX is somekind of joke. I trashed three of them so I have some experence here. COX engines will not take the strain, they will fail. Bob Davis has milked his COX head about as long as he can. But, I understand, everybody thinks this won't happen to me. It does. MEOA heads work better with the same result - DEAD COX. If in doubt do a search.

If you want a 1/2A diesel buy one (think PAW or some other purpose build marquee here).

regards - Steve B.

(in reply to lz-23)

RE: modifications to an 049 - 8/17/2007 10:20:44 PM

Posts: 10105
Joined: 11/22/2003
From: arlington, WA, USA
Status: online

Ditto on Cox diesel conversions. All that the Davis Diesel crank ensures is that it will be the rod that fails. If you love your Cox engine, just say NO to diesel.

_____________________________

Led Zeppelin is NOT "old fogie" music.

(in reply to burtcs)