let us talk about fuel tank clunks....

[orthobird]

for those of you who make your own tanks, what ever they may be, if you like the dubro milk gallon plastic, or the juice bottle / water bottle plastic, or the anodized aluminum caps, or if you use the stoppers with the compression plate...

lets talk about clunks...



i am interested to hear what are your experiences and pros and cons with different types.



specifically, there are the clunks with the felt, and the clunks that are filtered, and the plain old brass clunks with one or two barbs on it.



what are the pros and cons of each....

 

[Bipeguy03]

I usually run the standard dubro clunks, they don't have a filter in them of any kind. Then I use a Sullivan Crap trap between the tank and the engine,



Filtered clunks can get pugged/partially plugged and even with the clear water bottle type tanks you can't see that. With the in line crap trap you can see the crap in it, and if you take it out and blow air threw it backwards it cleans it so you can keep using it.

 

[orthobird]

Bipeguy03;11275 wrote: I usually run the standard dubro clunks, they don't have a filter in them of any kind. Then I use a Sullivan Crap trap between the tank and the engine,



Filtered clunks can get pugged/partially plugged and even with the clear water bottle type tanks you can't see that. With the in line crap trap you can see the crap in it, and if you take it out and blow air threw it backwards it cleans it so you can keep using it.

do you use a machined aluminum cap or the stoppers?

 

[TnAeroNut]

I just bought one of the SWB alloy stoppers. The package says for 5/32 tubing. I was planning on using 1/8 tubing - will that work? Related question... Is 1/8 the right size for a DA60?

 

[Bipeguy03]

Depends.



If I use the Dubro tanks I use the Sullivan aluminum cap conversion. If I run water a water bottle tank, I use the Cap from PSP.



I've used the plastic cap as well, no problems with them I just prefer aluminum.

 

[Bipeguy03]

TnAeroNut;11308 wrote: I just bought one of the SWB alloy stoppers. The package says for 5/32 tubing. I was planning on using 1/8 tubing - will that work? Related question... Is 1/8 the right size for a DA60?

Yep it will work, I just get a 1/8" drill bit and run it through the holes. It will still be tight to push the tubing through the stopper.



I use 1/8" tubing on everything, the engine will only use the fuel it needs as long as it's there!!!

 

[SleepyC]

I use Danhakl Tanks and just put them in.. no worries.





If you build your own, DO NOT leave 1 - 2 inchs of space between your clunk and the back of the tank. In a hover this can be bad... SERIOUSLY.

 

[Bipeguy03]

Bipeguy03;11310 wrote: Yep it will work, I just get a 1/8" drill bit and run it through the holes. It will still be tight to push the tubing through the stopper.



I use 1/8" tubing on everything, the engine will only use the fuel it needs as long as it's there!!!

Edit, I was thinking 3/32" not 5/32" tubing!!!! If the rubber stopper is tight around the tubing it will work!

 

[Ohio AV8TOR]

I have been using the PSP anodized cap and a Fuji bottle. It is a very nice quality cap. As for clunks I have been using the Walbro felt in Tank Fuel Filter clunk. I went that route after hearing that they hold more fuel for downlines. I use a three line system so the clunk pickup is only used for fuel going to the carg so it is an effective fuel filter.

 

[orthobird]

Ohio AV8TOR;11330 wrote: I have been using the PSP anodized cap and a Fuji bottle. It is a very nice quality cap. As for clunks I have been using the Walbro felt in Tank Fuel Filter clunk. I went that route after hearing that they hold more fuel for downlines. I use a three line system so the clunk pickup is only used for fuel going to the carg so it is an effective fuel filter.

do you believe, in any way, that the felt may or could act as an impediment to fuel flow? reason i ask, i have a 91" yak with a 70 cc twin motor.

tank full, cranks right up.

after about 6 minutes of flight, the tank is 1/2 full or so.



i noticed that if i do a humpty bump, then when i am in level flight and begin to pitch the nose down, then the engine sounds like it is starving, for about 2 seconds. i level her out, then sounds fine again. kind of weird. does not happen when tank is full, and the engine is not overheating.



when i landed it



i looked, and surely enough, if i tip nose down by 30 degrees, i can see in the tank that the clunk felt, about 1/4th is not submerged.

seems to me that the fuel would enter the fuel line via the whacking process.



can air get into the fuel line when it is in this position?

anyone else have any thoughts on this?



and in fact, this was the purpose for my post....