stunthanger.com

Engine basics => Engine set up tips => Topic started by: frank mccune on September 03, 2013, 01:36:09 PM

Title: I need advice for a good tank set up for profile stunt ship.
Post by: frank mccune on September 03, 2013, 01:36:09 PM

    I need some suggestions on tanks for a profile stunt ship.

    I have used a standard wedge tank. OK but it  wants to go too lean near the end of the run.  Could the tank be too large?

   I have used a standard wedge converted to a uniflow system and it is unproven as of yet.  I want a steady 4-2-4 run or a wet 2 cycle on my Fox and old O.S. .35 and .40 stunt engines.

   What about an old Veco T-34 profile tank? This is the one with the sharp crease in the middle of the outside wall for the fuel to gather.  I have been warned that these will not run correctly.  Would it work well if I converted it to uniflow?

   Perhaps a Sullivan SS-4 with a clunk-uniflow system installed.  Would this be worth the trouble?

   Perhaps I should just buy a Brodak uniflow tank.  If so which model would have a capacity of 3-4 oz. of fuel and run well?

    It has been over three decades since I fretted about profile fuel tanks! What is new?

    The hard tank with a bladder in it sounds really cool.  Is this worth the trouble for a sport flier?

                                                                                           In any case, tanks in advice,

                                                                                           Frank

 

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Balsa Butcher on September 03, 2013, 02:16:36 PM

For profile I recommend the GRW Products profile uniflow. Purchase from Eric at RSM. The 4 ounce tank is HF400U. Tubes are vented from the side to allow more room for mounting. Conventiently, the overflow also exits from the side. They give a very good uniflow type consistent stunt run and are easy to install and mount.  8)

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Bill Little on September 03, 2013, 02:18:31 PM

HI Frank,

Get a uniflow tank of the correct size.  Take the back plate off before you use it and check everything is "correct".  When you replace the back plate, pressure test it under water.  When you get it ready, try muffler pressure to the uniflow line.

BIG Bear
RNMM/AMM

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: frank mccune on September 03, 2013, 05:39:55 PM

     Hi:

     I can not find Eric Rule, RSM,or GRW by doing a search on this site despite RSM being lilsted on the Vendor's information.  How may I contact RSM et. al.

                                                                                                   Thanks,

                                                                                                    Frank

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Bill Little on September 03, 2013, 06:05:17 PM

Here you go Frank:  http://www.rsmdistribution.com/index-2.htm

Bill

P.S.  I looked in his first post under RSM in the Vendor's Corner and the link to his site was there. ;D

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Balsa Butcher on September 03, 2013, 06:09:00 PM

Try rsmdistribution(dot)com. Contact info is there. Unlike my esteemed collegue I don't feel it is necessary to completely unsolder the backplate unless you have a problem with the engine runs you are getting from it. It is a good idea to pressure test the tank though. Just block off two vents and blow hard into the remaining one while holding the tank under water. Any leaks will be noticeable as bubbles.  8)

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Tim Wescott on September 03, 2013, 06:18:23 PM

I seem to have some sort of a curse when it comes to metal tanks.  The only ones I've been able to get to run consistently have been small or modified to clunk tanks.

I just converted a plane from a metal uniflow tank (which was given to me by someone who had used it successfully) to a Sullivan rectangular tank set up for uniflow.

I think I could have converted the metal tank I had into clunk (with uniflow) in less time.

But the tank works like a charm.

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Reptoid on September 03, 2013, 07:20:36 PM

GRW no longer makes tanks, but Eric makes their series of tanks currently.
If you click directly on the link below, it will take you to Erics website: Then click on fuel tanks, then look at the two different types of uniflo tanks available.

http://www.rsmdistribution.com/index-2.htm


     I actually prefer the "Snub nose uniflo (U-Type)" as they are taller and shorter and fit better for profiles but either style of uniflo should give you perfect runs. Make your mount adjustable for height and start with it 1/8" to 3/16" above the centerline. That should be very close to start and you can fine tune the height to get even power inside/outside, or upright/inverted. Make sure you cap off the overflo after filling.
     I usually run a tube thru the fuselage and forward to pick up clean air. If you get a large variation from rich to lean and back in the wind, slide a short piece of 3/32" tubing inside the 1/8" tubing in the section that faces into the wind.
     I never use muffler pressure and don't understand why so many people have trouble trying to run a uniflo tank. The engine run will stay the same for the entire flight up to a lap or two from the end, and should go slightly rich before it leans out and quits if it's set up properly. H^^

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: Geoff Goodworth on September 03, 2013, 07:27:58 PM

I've had success with the Brodak Large Profile uniflow tank. It's deep with a chicken hopper type side and the distance between the spraybar and the tank outlet is not great.

http://brodak.com/large-profile-uniflow-fuel-tank-3.html

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: phil myers on September 04, 2013, 08:41:41 AM

Hi B.B. you could do a lot worse than the J.Miller style clunk tank   Uniclunk2-Model S.jpg
To adjust for lean/rich runs simply move the uniflow tube up or down. I tried to post a link to it here on SH.. I use 2 . one on a Magician (os35s) and a Cobra
Phil

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: phil myers on September 04, 2013, 08:45:40 AM

err.sorry my last post should have been addressed to Frank and not Balsa Butcher.
Phil

Title: Re: I need advice for a good tank set up for profile stunt ship.
Post by: frank mccune on October 03, 2013, 01:37:12 PM

    Hi:

    Thanks for all of the suggestions!

             
                                            Be well,

                                            Frank