I could really use some advice on sizing the gap between the filtered air box (FAB) and the cowl snout for my RV7A vertical induction setup. So far I have trimmed the FAB top plate back to where the cowl will just clear the front edge if I drop it straight down. How large should the gap be between the FAB and the fiberglass snout for the rubber seal strips? The seal material is 1.75 inches wide so I am guessing about 0.75 inch overlap with the FAB for riveting, 0.5 inch gap, and 0.5 inch overlap with the snout? Is that about right?
I am concerned about making the gap too small because of the threads I have read about FAB top plate cracking, perhaps caused by forces put on the FAB at engine startup due to relative motion between the FAB and the cowl. But the instructions don't give a dimension.
Note that I have a Catto 3-blade prop so I am also hoping to make the lower cowl as easy to install and remove as possible. So a related question is has anyone had success attaching the lower seal strip to the cowl snout to make cowl removal easier? It seems like that would work but I don't know if it would compromise the seal with a resulting loss of manifold pressure.
I am concerned about making the gap too small because of the threads I have read about FAB top plate cracking, perhaps caused by forces put on the FAB at engine startup due to relative motion between the FAB and the cowl. But the instructions don't give a dimension.
Note that I have a Catto 3-blade prop so I am also hoping to make the lower cowl as easy to install and remove as possible. So a related question is has anyone had success attaching the lower seal strip to the cowl snout to make cowl removal easier? It seems like that would work but I don't know if it would compromise the seal with a resulting loss of manifold pressure.