ORIGINAL: Cambo
I was wondering the same thing. I was looking over the firewall and really saw no need to pin it. For the firewall to come off it would have to rip through plywood at 4 points. This is much different that my glows were all it has to do is break the glue bond.
What do you guys think?
Trust me, those four point will come loose. I did not pin mine at first and found that after the one and only prop strike I had, that is exactly where the firewall came out. In one respect that was probably what saved the engine from ripping off the whole front end.
Now, during one of the many checkouts I did on this plane, I did find the glue coming loose on the firewall right where those 4 points are and took a needle and injected some epoxy into the joint and made a mental note to pin the thing because I did not have any dowel rod at the time. Problem was I tore the firewall off about 6 flights later (next day after I re-glued the joints)
You definitely want to pin the firewall when using any gas engine on any plane.