At 07:15 AM 9/9/2016, you wrote: >If you put a full 1/2 inch pice of 9 ply wood and then. The >aluminum 3 inch angle. Behind it. With the 5 attach points engine >mount. From great planes. >What does the neters think about this compination ?? +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Way over built !!! The firewall itself is not what breaks it's the attachment to the boat. see: https://dl.dropboxusercontent.com/u/32133949/100_1231.JPG Jeanette Rand once stated that an engineer once analyzed the firewall and it is good for 22G's. I did add a single layer of KR clothe to the vertical edges with a two inch overlap on the ply sides. I also used 3/4" X 3 1/2" spruce cross pieces top and bottom instead of the 5/8" X 3" spruce. My 0-200 hangs on a HAPI VW mount which does not place the mount near the longerons but more to the center of the firewall. Marty Roberts had a stock firewall with the same mount for his 0-200 and pulled 6 G's. Is thats strong enough? I'll admit to never having made a hard landing :-) to check my setup and have not pulled more than maybe 2.5 or 3 G's ever but my engine is still hanging out there. Larry Flesner
