Steve is correct in regards to the high amount of vibration the bonnet is subject to.
Even though I have used Camlocks and 1/4 turn fasteners in the restoration of classic biplanes like the Stearman, (which, with the Pratt and Whitney R 985 450 Hp radial engine has pretty good vibration on its own), I have had to replace a good amount of Dzus' that have worn the mounting holes in the panels to failure.
I have tried everything from chafe strips, rubber, shop rags, plastic washers, wood strips, incantations, etc. on the 3-W, with poor results.
Skybolt Aircraft Fasteners now offers, in addition to their excellent 1/4 turn and Camlocks, a new structural fastener called Skyloc EXT. These are built for high-load, high vibration applications where panels must withstand shear and tensile forces, such as in aerospace, defense, motorsport, and advanced industrial use.
The EXT has an external thread shaft configuration that, according to the manufacturer, resists loosening under severe vibration, provides a greater clamp load in primary and secondary structural panels, and has tolerance for installation variability, including curved panel geometry and minor misalignment.
Of course, one has to consider the unintended consequence of panel cracking under load, which leads one to think about the M3W motor mount kit, which leads onto think about cracked exhaust pipes... etc. etc.
More likely this will also be a winter project.
