Felt clunks
 

Does anyone know why ZDZ does not recommend felt clunks in the gas line? Or any filters in the gas line for that matter.
The question has been asked on the mfg forum but not been answered.

RE: Felt clunks
 

In our jets that we fly we have found fibers from the felt in our post filters after the fuel pumps and in the fuel pumps themselves...Fact is that the fibers WILL find their way eventually to the filter screen in the carb. [:@]--I don't use felt for this reason-- A much better filter is a Festo filter...I would imagine that ZDZ might be afraid that if you use too restrictive a filter or the wrong type it could cause issues. The Festo filters flow VERY well...Here is a link to Todd at Dreamworks RC and the filters.....[8D] The first is a 4mm filter and the other is a 6mm fliter. (mm is the tubing size)--You can easily fit Tygon to these filters...They are rated at 50 micron filtration but flow EXTREMELY well as we flow much more fuel in our jets than in the gassers...I use these in my gassers...The 4mm works well with medium Tygon and the 6mm works well with the large Tygon...Just unscrew the ends, push on your tubing over the barbs and put the compression fitting end back on and your are in leak-free business!!!..Hope this helps..;)...Tell Todd that I sent ya...[sm=thumbs_up.gif]

http://dreamworksrc.com/catalog/prod...roducts_id=776
http://dreamworksrc.com/catalog/prod...roducts_id=777

Kevin

RE: Felt clunks
 

Neat stuff Kevin. Will a 3/32"id neoprene tubing fit?

RE: Felt clunks
 

I have had one experience of fibres from a felt filter partially clogging my Walbro carb fuel screen. The symptoms was that the engine would start normally but would not run above a fast idle.

That Festo filter looks like a good thing to have, but now I simply do a seasonal check of the screens for any debris, plus the fact that the felt filters do such a good job of filtering I still use them.

Karol

RE: Felt clunks
 

I have no idea why ZDZ would do that. If they have concerns about felt fibres entering the carb screen, a small instruction can cure that risk.
If a felt clunk is washed/massaged in gas well before fitting, all loose fibres will be washed out and the filter is ready to go.
It has a few advantages in that it will eliminate suction line bubbles, regardless of fuel foaming in the tank. This clunk type also will draw fuel from the tank until it is bone dry, and it filters absolutely everything out!

RE: Felt clunks
 

So will a sintered bronze clunk without the worries of having to "massage" the clunk or fear of fibers---There are also other types of clunks that filter without causing fibers to sluff off--I believe that Don's Hobby Shop sells a porous nylon? membrane clunk that works well...Also---Have you guys thought about the vent line for a filter??? There is suction on this line when the engine is running and this line will suck up debris from the ground that the prop stirs up..Have a look...I got mine at Don's Hobby Shop for $9.95--

Kevin

RE: Felt clunks
 

Yes---I would use the 4mm filter---It should stretch over the barb---But I prefer Tygon as it is less likely to split or become brittle with age...

Kevin

RE: Felt clunks
 

Here is a shot of a 4mm Festo filter in my jet which is fed by Tygon..Tygon turns dark with the jet fuel and oil in the fuel combo...My fuel in my jets is filtered a total of SIX times before the injector needles see any fuel...The injectors are the size of hyperdermic needles are can't stand to be clogged....My gassers get fuel that is filtered four times before the needle and seat see fuel...The last filter being the screen in the carb..

Kevin

RE: Felt clunks
 

As you all can see I'm kind of anal about filtering fuel---I have YET to have a flameout in any of my jets, nor have I had any dirty fuel issues in any plane that I fly---If you close your system to the chances of dirty fuel contamination (including the vent line) you WILL have less worries and less maintenance issues in the long run...

Kevin

RE: Felt clunks
 

I don't think there is anything anal about someone who takes all possible precautions against dirty fuel reaching their engine. My method is, a fine nylon filter on the pickup line in my fuel jug, a small auto type paper element filter in the line to my manual pump and a felt filtered clunk before any fuel reaches the carb.

I never gave it much thought about putting a filter on the end of the vent line, even though I have on occassion seen signs of crud there. Will think about using one now as I fly from grass fields which sometimes can be very dusty.

Karol.

RE: Felt clunks
 

The bronze filter, that I also use, has one disadvantage, It is not soft like the felt clunk, and will batter the tank bottom to death.
BTW, it is "massage", like kneading, and not "message" like sending a message. You think I rode the small bus?

RE: Felt clunks
 

That is exactly what I do, and my carb screen stays clean very well.

RE: Felt clunks
 

Ha HA HA!!! That's funny!!!:D---I think that perhaps I needed to ride the short buss as I incorrectly spelled "massage"---I edited my post to correct it...When I wrote this I had just awakened---I haven't been up all day as you have...:)---I really like your expert advice concerning engines and power figures---No short buss for you!!!

Kevin