Technique for Extended Test-Bench Run with 8cc Tanked Engines

dckrsn wrote:Great idea, thanks for posting it Kim.
I'm guessing it would work for vented
backplates too.
My neighbors are gonna love it.
Bob

It's vented, see the plug he made for the vent on the right side. Same way with the Babe Bee backplate if you want to do that.
I may add an extended flying bladder on my Black Widow powered planes. I never get long enough flights with them. I just learned how to make one for my Tee Dee and it works great. It's a balloon with a perforated tube extending the length of the balloon. Suck all the air out and put fuel in it. Works like a charm.
Here's a picture:
http://www.rcgroups.com/forums/showpost.php?p=19851117&postcount=13

Is there a reason you can"t add fuel to the tank while it is running? It obviously it won"t work for flying but what about test runs? Possibly it would flood the engine?

cribbs74 wrote:Is there a reason you can"t add fuel to the tank while it is running? It obviously it won"t work for flying but what about test runs? Possibly it would flood the engine?

I always refill the tank when the engine is running.

So is no modification to the stock 8cc stunt tank required for this?

microflitedude wrote:So is no modification to the stock 8cc stunt tank required for this?

No, other than plugging the other vent so it will pull a vacuum to draw from the external tank. See the capped piece of fuel line on the right vent in the picture.

RknRusty wrote:

microflitedude wrote:So is no modification to the stock 8cc stunt tank required for this?

No, other than plugging the other vent so it will pull a vacuum to draw from the external tank. See the capped piece of fuel line on the right vent in the picture.

Ah, I see now. Wish I had more room in my plane.

Admin wrote:

cribbs74 wrote:Is there a reason you can"t add fuel to the tank while it is running? It obviously it won"t work for flying but what about test runs? Possibly it would flood the engine?

I always refill the tank when the engine is running.

It would flood the engine, but I use a small pair of surgical clamps on the external line 'till the engine is started. I've sure it helps to have the tank a bit higher than the engine to let it siphon into the Bee's tank.

I refuel them when running too, and this extra stuff may not be worth the trouble, but does save spraying fuel on the stand. In the case of the small tanks, it would let you settle in with a long run without fueling the engine every 2-3 minutes.

Also, if you've got the pickup tube someplace other than the bottom of the tank, it won't give you a full tank's run. This way, it'll feed 'till you want to stop it, AND give you a visual reference of how much fuel you've used. Sometimes, I like to start them and let 'em run, with no hurry to get the tach or camera.

It's not something I thought everyone would use...just posted it in case it might come in handy for someone.

Kim wrote:
It's not something I thought everyone would use...just posted it in case it might come in handy for someone.

For folks wanting a longer run when flying (particularly R/C), one option was to drill the tank and plumb in an external tank. I was never inclined to drill the tank (not wanting to ruin the tank being foremost). Kim's approach gives you an option for good flight times using an external tank without destroying an existing COX tank. You do need to ensure the fuel tubing is tightly secured and you must be able to block any other vents.

Yeah, I've got a pretty nice Golden Bee tank with a big hole drilled in it. The hole is plugged with a screw and nut, and works fine...but the blemish just sort of jumps out at you!

Years ago drilling out tank was quite common. Parts were easy to get if you wanted to make like stock again. I never did this as just went to a TD. .049. I see many engine set-ups on this forum and amazed on how long some fuel lines are. I put tank as close to engine and use shortest fuel line that will work. From smallest to biggest.010-.80 sized engines. Maybe its just me but long fuel line is asking for problems.
Dan

dankar04 wrote:Years ago drilling out tank was quite common. Parts were easy to get if you wanted to make like stock again. I never did this as just went to a TD. .049. I see many engine set-ups on this forum and amazed on how long some fuel lines are. I put tank as close to engine and use shortest fuel line that will work. From smallest to biggest.010-.80 sized engines. Maybe its just me but long fuel line is asking for problems.
Dan

It is if the engine has to draw the fuel, but if you've got the tank even a little elevated above the spraybar, the engine won't know the difference and will mostly run just fine. This is ONLY true in sport planes that aren't gonna try to sustain inverted flight.

On my first "R/C Cross Country Flight" to raise money for the United Way, I even connected two tanks in series to make the hop from my company parking lot to a landing at a park 9 miles away. I put a tank under the wing, ran a line for fuel to the internal tank, and a line for pressure from the O.S.'s muffler, and off we went. I still manged to run out of gas because of slow traffic (yes, even in the country...tractors, you know), and had to make a rather exciting landing AND takeoff between the trees on the park's narrow drive.





"...And the Crowd goes Wild!"









Anyway.those were my dealings with it.

Well Kim you do the best things with simple trainers!
What are the legalities of flying cross country?

nitroairplane wrote:Well Kim you do the best things with simple trainers!
What are the legalities of flying cross country?

None that I know of...yet. I just "cowboyed it" out in the boondocks, raised right at $200 bucks, AND had a great time. Of course, a single raghead could change all this, much like what the 9-11 rug-benders did to general aviation and the second amendment, but for now, in spite of ole Box 'o Rocks, America is still a relatively free country !

Trainers and their kind ARE highly underrated! There are limitless things a good stable lifting platform can do. I haven't even started some of the night time experiments I want to do...articulated spotlights on servos, aerial sound systems, and lighted signs towed behind a plane! Figure I may initiate an environmental disaster by causing the local Meth-Heads to flush their stash! Then...Goodbye Snail Darter !

Trainers and their kind ARE highly underrated! There are limitless things a good stable lifting platform can do. I haven't even started some of the night time experiments I want to do...articulated spotlights on servos, aerial sound systems, and lighted signs towed behind a plane! Figure I may initiate an environmental disaster by causing the local Meth-Heads to flush their stash! Then...Goodbye Snail Darter !


LOL yeah i suppose they are perfect for almost anything!
Imagine a cross london tee dee .010 flight

nitroairplane wrote:Trainers and their kind ARE highly underrated! There are limitless things a good stable lifting platform can do. I haven't even started some of the night time experiments I want to do...articulated spotlights on servos, aerial sound systems, and lighted signs towed behind a plane! Figure I may initiate an environmental disaster by causing the local Meth-Heads to flush their stash! Then...Goodbye Snail Darter !


LOL yeah i suppose they are perfect for almost anything!
Imagine a cross london tee dee .010 flight

Now THAT would be cool !!!! But don't even THINK about doing it without video coverage !!! Maybe a lap around Big Ben...but be careful not to hit it...I hear it's leaning !!!!

LOL i was really thinking about getting a .049 sailplane up to about 1,500 feet in central london but the noise!
Still i will do some research.

nitroairplane wrote:LOL i was really thinking about getting a .049 sailplane up to about 1,500 feet in central london but the noise!
Still i will do some research.

MUFFLE, MAN, MUFFLE !!!!!!

yes then i can run better pressure on the tank but i dont know!
Maybe I will maybe i wont but i would love to do it some day.

nitroairplane wrote:yes then i can run better pressure on the tank but i dont know!
Maybe I will maybe i wont but i would love to do it some day.

Cruise one of these sucker across the Thames! INSTANT popularity !

Kim wrote:

nitroairplane wrote:yes then i can run better pressure on the tank but i dont know!
Maybe I will maybe i wont but i would love to do it some day.

Cruise one of these sucker across the Thames! INSTANT popularity !

LOL yeah it would be popular especially with the COD guys
No i think that .010 Spruce Goose would be more fun