achap7

Hey guys (or gals), I'm building an Thunder Tiger 30% yak with a DLE 55 engine and I need to know if I can position the gas tank below the carberator ie below the service tray instead of above. This will put the tank in the belly of the fuselage. I only have experience with glow engines.


Thanx, Tony C.

speedracerntrixie

My Feedback: (29)

You can but it may make pulling fuel to the carb a little difficult for the first run or any time the fuel line may become dry. Is there a reason you do not want to put it on the top of the tray?

Gray Beard

My Feedback: (-1)

You can put the tank in the tail if you want, makes no difference to the engine. Most people like to stick them about center of the CG though. HIgh/low makes no difference. Once it's choked it's good to go.

nonstoprc

My Feedback: (90)

There are two drawbacks.

1. the tank is difficult to access. A minus when you want to check the inside of the tank.

2. if the deck (or the ceiling in your proposed mounting method) to attach the tank is off the center line of fuze, a filled tank will put weight on the belly side of the plane, when the plane is vertical. The plane probably will not fly straight vertical.

The carb should be able to draw fuel with force and I do not see a problem with engine running.

achap7

The reason I was wanting to place the gas tank below the center mount was an attempt to move my throttle and choke servos further away from the ignition (currently where the manufacture placed the tank). I was recently advised that my servo location ~ 6 inches behind the firewall should be okay.

So I think I'll leave the tank above the center mount where Thunder Tiger placed it


Thanx, Tony

FireBee

My Feedback: (34)

Tony,

Just checking. you are not using a standard FM receiver are you? that advice on 6" sounds like what I got and is old school. if you use strandard FM your plane will crash!!! we had same at our field as the "newbie to gas engines "just did not know and his corsir, pilot by our local expert, flew about 5 ft up and then no control. post crash reveiled he was using standard FM receiver.

PCM is good in gas but needs some space seperation between switches, ignition module, ignition batt, and throttle servo should not be metal wire. we have a 3 inch rule where, if you imagine, cut the plane in half and all the electronics for the engine are seperated by 3 inches from the receiver/batt packs and switches for aircraft control.

2.4 is best bet and does not require this space seperation. again, just making sure.

Gas engines do not care as to fuel tank location as others have stated. My G-62 in 1/3 laser is just in front of the wing tube. thus ahead of the CG so weight changes ever so slightly.

FireBee

My Feedback: (34)

also, recommend a B&B tank. nice fuel filter pick up and comes in square or rectangular. you will need 24-32 oz for DLE55 and have plenty of flight time. I use 32 oz for all my 3w-50 and G62's.

They feature a front screw cap so inside fuel tank inspection is also easy. We also file a rough spot and silicon glue the screw cap to the tank lip. 3 of us had a slight unscrewing and we noticed fuel in the threads and thus could not get a reliable idle. silicon fix and no problems in 3 years.

recommend the book on big bird set up: from Don Apiostolie (sp?) . see Don's Hobby shop Salina KS

Gray Beard

My Feedback: (-1)

For FM the rule of thumb was 12 inches. I have even moved everything back three feet and still had RF. PCM cured the problem but you can get away with a lot more if your using 2.4.

nonstoprc

My Feedback: (90)

I have heard B&B tanks. What is the benefit of using it?

On 50cc planes, I use 20-24cc tanks. Enough for 10-12 minute flight and save weight.