Brodak CL Basic Trainer 049

I just had a look back at your other post where you had a picture of the tank installed on the plane.

This may sound like a silly question, but are you connecting the fuel line from the engine to the correct pipe on the tank?
It should connect to the one which points forward.

Thanks for your questions. I appreciate your query very much. The wedge shaped fuel tank has 3 tubes, 2 nos of tubes vertical - one for filing fuel and the lower one for overflow, the one tube that is horijontal and pointing towards the engine,, is for my engine pick up of fuel. This is how is written in the Brodak's fuel tank manual. Still no luck more than 1.2 minites with 11 cc fuel.

Did you pressure test the tank to see if it was leaking? One problem with running on the ground is that the airstream is blowing over the vent pipes. This siphons fuel from the tank. I personally cap the top vent which I fill through after filling. Not only does this slow down tank siphoning, it also improves fuel draw. This would improve your run time a bit more. You really can't accurately gauge your run time on the ground vs flying the model. Personally, if this is your first control line model, go fly it and see how it responds, if needed change the tank out for larger.

Yes, I have pressure tested the tank - it was not at all leaking. Itbis my 3rd control line plane, the 1st one was at the age of 12 years , it's engine was a replica of frog 1.5 cc diesel engine and never flew : after a gap, I reconstructed the old cl plane, fitted with a PAW 15 engine, the engine was running at abt 11,000 rpm, 9 inch x 6 inch propeller, but the model never left the ground. Now the model is Brodak basic trainer with cox 049 engine - I have plan to make senior peacemaker with PAW 15 diesel engine I already have.

I have made fuel :25% nitro, 20% castrol, 55% methanol : the fuel tank is from Cox's starter kit and they say it is 3/8 oz= 11 cc wedge tank; I have measured 15 cc fuel by a measuring cylinder and by a squeeze bottle ( the outlet if the squeeze bottle is nitro fuel pipe if cox, having 1.5 mm internal dia) --- only 4 cc of fuel ( maxm) goes inside thebtank and fuel starts coming out of the overflow pipe ( the tank was tested for leakage and any blockage ) --- it the fuel tank that is holding only 3 to 4 cc fuel maxm - I have started the engine and held the model with its left hand wing vertical andvright hand wing downwards sovthat the vertex of the wedge tank is at the bottom - the engine rubs for 1 min and 25 second - the needle is open for 4 turns... Now why only 3 to 4 cc fuel goes inside a 11 cc capacity fuel tank - repeatedly ran 4 times full tank and the same result... Where is the fault? Is the fuel tank defective? Pls guide

Well, I did a quick calculation and the 3/8 oz. should indeed be 11 ml. Maybe try filling it through the front pipe with the plane nose up. Just keep trying different pipes at different angles for filling.

Maybe the overflow pipe is too short. Flip the plane over and fill through the pipe which was the overflow when upright.

At this point i would buy another tank and try it there not that expensive / or take that one apart and see what is going on with it inside. Also 4 turns seems like a lot is the engine screaming ?!?!?  

Yes sir, I am buying another tank from cox ca.

Yes sir, the sound of the engine of yours

https://coxengines.ca/images/P/cox%20049%20fuel%20tank%203-4%20oz%201.jpg ------>>>i have got this fuel tank, brand new and tested, can I use it on my control line model... Pls guide

That fuel tank is 3- line operation fuel tank.... From cox international

It will work what oz. is it 1/2 or 3/4 ? The mounting is going to bee a little tricky , i would get a small piece of thin rubber and put between the tank and fuselage and just tye strap it on for now with small straps.

This thing ever going to fly?

barun wrote:Yes sir, the sound of the engine of yours

https://coxengines.ca/images/P/cox%20049%20fuel%20tank%203-4%20oz%201.jpg ------>>>i have got this fuel tank, brand new and tested, can I use it on my control line model... Pls guide

I think it will be difficult to mount this tank to a profile fuselage.  It is designed to be housed inside a built-up fuselage.
You really need to stick with a wedge tank like you had before.

Then there is always a bubble bottle tank or balloon tank that would also work nicely for you. Easy to build either, and would work fine.

Oldenginerod wrote:

barun wrote:Yes sir, the sound of the engine of yours

------>>>i have got this fuel tank, brand new and tested, can I use it on my control line model... Pls guide

I think it will be difficult to mount this tank to a profile fuselage.  It is designed to be housed inside a built-up fuselage. You really need to stick with a wedge tank like you had before.

It's a free flight tank but can be made to work, no less worse than the built in plastic rectangular tanks or moulded cavities in an RTF. The fill / overflow tubes are normally stubbed in just inside the tank, pickup tube positioned in the rear lower corner. To simplify installation should be mounted on the inboard side of the profile fuselage instead of outboard. This will allow easy access to fill and overflow, and place the fuel pickup tube in the lower rear outside corner so it can drain properly during flight until empty.

Mind you of course, without disassembly / unsoldering tubes, I am only speaking of conjecture. However, a quick check can be done by filling interior with fuel from a fuel bulb, then lay tank mostly on its side with the pickup tube exiting to the side (simulate centrifugal force of the flying circle). Suck the fuel out with the fuel bulb. Amount of fuel remaining will let you know how that pickup tube is really positioned and whether tank will work without further changes.

The tank is 22 cc = 3/4 oz tank . I have bought 3/8 oz wedge tank from Bernie and on the way . Till suchtime, I will practice with this fuel

If that tank is mounted on a profile with the two top tubes forward and outboard, the pickup is in the wrong place. I use those tanks for mouse racers. I pull out the stock pickup and patch the hole, I then install the new pickup on the bottom far corner straight in to the rear.

The sq. Tank is fitted as shown in the picture. Outboard side. I tried to test in the static I. e in the ground. The fuel% is 25% nitro, accidentally I had added more castrol ( nearly 30% ) and the rest is methanol ( abt 65% ) - the engine started very rich but could not continue ... What is the problem on not starting properly - with the wedge fuel tank there was no starting problem - tomorrow I will again try with 20% castrol ( instead of 30% ) , 25% nitro and 65% methanol --

Dear all __ pls suggest - where I am wrong? ( my 11 cc wedge tank is faulty and takes only 3  cc of fuel) ... I have ordered wedge tank of 11 cc from Brodak... on the way -- pls guide --- sorry to bother all if youv

Sorry missed the pic of my model

Another point I missed, when I put igniter to the glow head, there was a sizzling sound ( putting bacon on very hot oil) - there was excess fuel, I blowed it out and primed again andvtried to start - but not started - if more fuel is taken inside the engine - the sizzling sound increases...

Your tank is mounted correctly, the plumbing inside the tank is incorrect. That's your problem. That tank isn't designed for control line use. As George mentioned, it's designed for a full fuse plane like a free flight. It can be made to work for control line but the piping has to be configured for it.

Hello Ken, thank you very much. Just another thing, castrol 30% , will it effect starting of the engine.. Pls