Since my obsession with this design has not diminished since I was a young boy I'll share some of my findings with you.
I actually did exactly what phil suggests on my straight wing version. I'm not going to disagree with Phil because I have heard that. After many conversations with Larry, he always comes to the leading edge reinforcement being the culprit. He really never cared for the 1/8" 5ply leading edge brace. He said his all used 1/4"x3/8" Spruce reinforcement behind the leading edge rather than 5ply. The area in question is the notch for the engine. The 5 ply was a suggestion by Carl.
The two taper wing version 12 planes so far have not folded with the 1/8" doubler. The straight wing version with spruce doubler and sheer webs can also be used as a surf board. I had did the sheer webs on that because I thought I needed the added rigdity because I was using monokote. I have since met Andre and he has a Monokoted Taper wing with no mods. His ofcourse is fitted tremendously well. A key to this design.
I plowed the straight wing in nose first at 120mph and the only things that survived were the leading edge and trailing edge, due to the sheer webs. Keep them light is key if you really want to maximize performance. I have 1 flight on my newest and I can see the improvements from 17 to 18.5 oz. He gives the suggested wood weights on the plan. Make sure you bush and put "L" bends on your stabilator pins! ask me how I know. I have some pics of interest to share.
Everything that Tom sez.
My Scrambler design(M.A.N.-1971) , which has been flown to 119.7 MPH on 35% nitro has some of the Super Satan DNA. We built ours with the 5 ply brace and identical pacifier pod as the Super Satans.
No folds.
Two reasons:
1)The five ply was grain oriented properly; that it is span-wise.
2) Larry Scarinzi's pod is an INTEGRAL component of the the center-wing structure. If some other fuel cavity device(e.g.- Hormel Can, Miss Clariol soft nylon bottle, etc.) is used, all bets are off.
My Scrambler uses a "Warren-Truss" rib arrangement and thus no center spar. Never a fold.
I witnessed one fold in the late sixties by a NYC combat flyer who neglected to use Larry's fuel pod design.