Lil Tiger - Gloss Pumpkin Orange

Thanks Fred, I wouldn't know how to rig up a balloon pressure system. I have only used muffler pressure on my R/C engines. Isn't there a tap on the crankcase for pressure? I may have to use a Medallion instead. Going to remove it and test it first anyway.

Model was set up for a Perfect tank of which I have many. A "Perfect" fit I would say, slipped right in.



Used a newer one.

I have some 15% off brand and Cox 20 and 25% fuel. Thinking the 25% a 6/3 and Mark.

A bladder is simpler than a pressure tank, and gives a nice even run.  There is a trick to start them.  Run off a prime, and then open the fuel line quickly with your fingers pinching the line, or a wire leadout connector or surgical clamp.  The bladder is just latex tubing tied onto regular fuel line with maybe a knot on the end.  I don't like to use them, because I am never quick enough to get at the clamp, but with two people it works well.  There are a few videos showing how.  https://www.youtube.com/watch?v=fPmO4y_Wfd8 Rusty has  a couple good videos too. A backplate pressure tap is probably better than the nipple on the plastic crankcase, IMHO. The easiest thing is a new venturi as was mentioned. The tank is a bit low but it may be ok.

Having the tank that low is going to be a problem. That wedge design is another. Perfect makes a longer one that doesn't protrude so far outboard. Achieving the centerline of venturi in both horizontal and vertical is optimal. Some of this can be accomplished by shimming the engine off of the bearers with aluminum.  These issues automatically place the engine in a lean condition. When the head pressure of the tank lessens both of these issues will more than likely just cause the engine to quit due to excessively leaning out. I personally would notch out the wing for the tank and raise it. If you don't like the look of the notch you can place fairing blocks around the tank from the fuse to the wing root.

Tank location might work if it were an A.C. Gilbert .074 or .11 Thunderhead. Engine likes the venturi above tank level.

It's not realized how difficult it can be to make a speed plane tank. The forces on the fuel load are responsible for the inconsistency. This can sometimes be quickly recognizeable on launch. Bob's example assuming he provides the stock venturi will run on the ground and one can needle the engine to make it run. Another problem that tends to occur is that in flight when the engine is "On", the speed increase dramatically and then the opposite happens. This is due to the plane yawing out and the fuel pinned in the corner, it feeds, then it doesn't, and back again. This is why a wedge is not a good design for this style of engine run. However, I have had somewhat success with the wedge by pulling the pickup slightly out of the back corner. This might take some trial and error by unsoldering it and pulling it forward a 1/8" at a time. I mention this all the time, a Perfect tank doesn't have it's pickup tube soldered internally, it must be soldered to the side wall of the tank. They pushed the tubes in, put it on a hot plate to solder and out the door it went. The tubes in the tanks can be ANYWHERE.

           Another option is to use uniflow, however I have never had good success using it on a wedge tank. I think turbulent bubbles do funny things due to the rounded inside portion of the tank when the uniflow pipe becomes uncovered. I wouldn't even consider crank pressure without experience first. It just floods the engine if one isn't up to par in the starting procedure and many times the hole for the pressure tap is far too large. You only need a hole that's a few thousandth's.

Bob is that scratch built or a kitbash the fuse almost reminds me of my buster , neat looking plane.TJ

There are a couple different versions of the “Ole Tiger” on Outerzone, nothing on a Lil Tiger.  This is the 14” wing span version.
https://outerzone.co.uk/plan_details.asp?ID=3477

YakNine wrote:Bob is that scratch built or a kitbash the fuse almost reminds me of my buster , neat looking plane.TJ

Thanks, You just helped me stop scratching my head. I knew I had seen something like it before. Yes, a SIG Buster, got one up in the loft with intentions of building it some day.



The Lil Tiger is a Dumas kit.

Bob

We have been racing these Buster and Shoestring Sig kits for the last couple years with LA .15s supplied by the club so no one cheats.  The Buster is quicker.  I think I got first at the last race.  I am usually the pilot hoor.  Get a bit tuckered out in my old age, but need the exercise.

aspeed wrote:The Buster is quicker.

This is understandable, Buster is 24 in. wingspan and 140 sq. in. area. Shoestring is 28 in. wingspan and 150 sq. in. area. Buster is cleaner aerodynamically.

aspeed wrote:I think I got first at the last race. I am usually the pilot hoor. Get a bit tuckered out in my old age, but need the exercise.

Congrats on the win, young man.

rsv1cox wrote:

YakNine wrote:Bob is that scratch built or a kitbash the fuse almost reminds me of my buster , neat looking plane.TJ

Thanks,  You just helped me stop scratching my head.  I knew I had seen something like it before.  Yes, a SIG Buster, got one up in the loft with intentions of building it some day.



The Lil Tiger is a Dumas kit.

Bob

Nice plane there. When you decide to build that Buster, it would probably be a good idea to trace out the parts in case of needing to reproduce them if needed. Or, in case someone else may want to build one....... Always wanted a Buster or Shoestring but never thought I would have an engine that fit. However, I have since gotten a couple engines in that range. I do really like the orange color on yours.

Me too, Chancey. It's come find me orange.

Not very fuel proof though with thinning around the engine and spotting on the wing. Maybe rattle can, could even be that Krylon Orange. I don't recall Top Flight ever offering an Orange color.

If I do use it, I will top coat it with Lustrekote clear.

Bob