HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 03, 2012, 03:11 PM
Registered User
Joined Apr 2012
537 Posts
Discussion
We used to cut a hole in the fuel tank of a Super Bee

Then we'd remove the original, small, curved fuel line and replace that with line that exited the drilled fuel tank and went to an external tank. It seemed like a perfect way to improve, at virtually no cost, the primary draw back to those great reedys, the limited fuel tank volume/tlime in air. Great idea! But I never got it to work, or work well. Seems the carbureator draw was not enough to pull fuel to the spray bar. Has anyone ever used crankcrase pressure to push fuel in reedys? There must be some rubber fuel cell or external tank configureation that works well. Any ideas?
If I could firgure out a good way to adequately fuel a reedy with an external tank or fuel cell, I'd be considering building a nice "Lil Jumpin Bean" or maybe even a "Lil Satan or a very light, no landing gear "Baby Ringmaster"
tigreflyer is offline Find More Posts by tigreflyer
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 03, 2012, 03:34 PM
Registered User
Beaumont tx
Joined Oct 2004
3,731 Posts
I think there are still "tank extenders" that go between the backplate and the tank end. I used to do what you're talkinga bout and had little trouble as long as the external tank was small, close as possible to the engine and mounted a little HIGHER than the center of the stock tank. It's no good for inverted flying, but I wasn't doing that back then.

howell
gwinhh is offline Find More Posts by gwinhh
Reply With Quote
Old Sep 03, 2012, 08:27 PM
Registered User
Canada, ON, Cottam
Joined Jan 2012
1,272 Posts
You could use a low pressure bladder if you like hassles. A "Little Red Cap" works well. It is like a kitten size rubber. A pressure fitting on the side of the crankcase has been tried and works, kind of hard to install.
aspeed is online now Find More Posts by aspeed
Reply With Quote
Old Sep 04, 2012, 07:47 PM
Registered User
flyelectcl's Avatar
Joined Oct 2008
185 Posts
Pressure doesn't work well with a reedy. The needle is too coarse and sensitive. I've tried it. Put a pressure tap on the crankcase. Maybe an external needle would work to do what you are trying.
flyelectcl is offline Find More Posts by flyelectcl
Reply With Quote
Old Sep 04, 2012, 08:51 PM
Registered User
United States, TX, Spring
Joined Jul 2010
197 Posts
Why destroy a Bee tank when you can use a plastic "horseshoe" backplate and any external tank you want?

http://www.ebay.com/itm/Vintage-Ogaw...item3f1bdfa202

or:

http://www.ebay.com/itm/Vintage-Ogaw...item3f1bdfa202

Both with fine-thread needles.
Gnu4FF is offline Find More Posts by Gnu4FF
Reply With Quote
Old Sep 05, 2012, 01:19 PM
I am 5' 8" the Taube is 7' 4"
Clancy Arnold's Avatar
USA, IN, Indianapolis
Joined Jan 2008
617 Posts
I modified the tank on a Cox .020 PeeWee for an external tank feed. It works fine. The rubber balloon is inside the 35mm film can for protection.
Clancy
Clancy Arnold is offline Find More Posts by Clancy Arnold
Reply With Quote
Old Sep 05, 2012, 01:25 PM
Registered User
Joined Apr 2012
537 Posts
Quote:
Originally Posted by Gnu4FF View Post
Why destroy a Bee tank when you can use a plastic "horseshoe" backplate
Both with fine-thread needles.


We were doing this before the plastic backplates were invented.
tigreflyer is offline Find More Posts by tigreflyer
Reply With Quote
Old Sep 11, 2012, 06:39 PM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,687 Posts
Quote:
Originally Posted by tigreflyer View Post
Then we'd remove the original, small, curved fuel line and replace that with line that exited the drilled fuel tank and went to an external tank. It seemed like a perfect way to improve, at virtually no cost, the primary draw back to those great reedys, the limited fuel tank volume/tlime in air. Great idea! But I never got it to work, or work well. Seems the carbureator draw was not enough to pull fuel to the spray bar. Has anyone ever used crankcrase pressure to push fuel in reedys? There must be some rubber fuel cell or external tank configureation that works well. Any ideas?
If I could firgure out a good way to adequately fuel a reedy with an external tank or fuel cell, I'd be considering building a nice "Lil Jumpin Bean" or maybe even a "Lil Satan or a very light, no landing gear "Baby Ringmaster"
Worked fine for me on RC models. Secret is getting external tank the same height..IIRC..a LONG time ago.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Old Sep 11, 2012, 07:55 PM
Registered User
Joined Apr 2012
537 Posts
Eric Rule says balloon tanks are the best bet for reedys or other .049s.
tigreflyer is offline Find More Posts by tigreflyer
Reply With Quote
Old Sep 11, 2012, 09:48 PM
Old Timer
The Kiwi's Avatar
USA, TX, San Antonio
Joined Jun 2010
831 Posts
I used shaft-valve 049s

Personally, I never acquired any reed valve anything for my own use, although I did have Medallion and TeeDee 049s.

I never paid any attention to the silly spelling for the smallest, weakest Cox Bee. "Baby / Babe" meant nothing to me. However, I couldn't help but see the constant Cox ads in the magazines, and my kids liked little engines, so I'd get them the Medallions. They bought their own Black Widows and some other performance class reed things from their chores earnings.

There was a Golden Bee, and other manufacturers had Super This and Super That, but I am almost certain that Cox never named any reed valve 049 a "Super Bee" ~~ Dodge is the one that did that.


Kiwi
The Kiwi is online now Find More Posts by The Kiwi
Reply With Quote
Old Sep 12, 2012, 12:29 AM
Registered User
Joined Apr 2012
537 Posts
The Cox P40, at least the older ones with the metal fuel tanks, came with Super Bee engines. This name was printed on the P40 box and in advertising for the P40s. The difference between Baby Bees and Super Bees was that Super Bees came with dual transfer ports in the cylinders. This increased power/RPM and fuel consumption. The Golden Bee had the Baby Bee, 1 transfer port cylinder with what Cox called the "stunt tank" an 8CC tank that allowed inverted flight. The Black Widow had the same 8CC stunt tank with the 2 transfer port cylinders. A Baby Bee might turn 17K RPM, a Super Bee or Black Widow might turn 19K RPM. (with the same propeller of course). The last RPM/HP increase came from shortening the piston skirts allowing more air fuel mixture to enter the combustion chamber, and lightening the rotating mass or piston weight in any engine increases RPM this might be worth another 1K RPM. These engines varied tremendously in RPM-some Baby Bees might turn close to 19K RPM-but the slickest trick in increasing RPM in reedys is using a light, mylar reed as the stock Cox reed often starts to float above 17K RPM. I also asked Bernie, at Cox International the power differences between a plastic back plate and a conventional 8 CC stunt tank configureation and he said the difference was negligable and when pressed he said a metal tank might have a very, very slight advantage of around 200 RPM over a plastic back plate. Like the mouse racer said, lapping in the engine and glow heads is essential in increasing reed valve engine performance. Also, earlier in this thread, it was demonstrated that the plastic backed reedys are lighter. I'll build a very light Baby Flite Streak with a Killer Bee. The Killer Bee is plastic backed with the dual port cylinder, fine adjust/better needle valve and a mylar reed and the lightened SCI piston. I know my ST G21 Combat Specials and my OS 35 Stunt engines are less troublesome and far better engines, but I learned 90% of all I know about CL flying flying reedys, thus I'm compelled to build one now that will fly far better than the TD4 and PT19s I learned on 50 years ago.
tigreflyer is offline Find More Posts by tigreflyer
Last edited by tigreflyer; Sep 12, 2012 at 01:35 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Air hole cut outs on a Electrifly super sportster? copperbricks Sport Planes 9 Jun 26, 2012 11:04 AM
Question Can I drill a hole in the exhaust for pressurizing the fuel tank? fixed3d Engines 7 Jul 09, 2009 05:38 PM
holy zagi batman... what do u use to cut big holes in foam Beige Foamies (Kits) 6 Sep 17, 2002 01:17 PM