Brief Description: Drill/Bolt Engine Mount to Firewall
Since I've been adding a bunch of stuff to the firewall I decided it was about time to drill and install the engine mount. I didn't want to run into clearance problems between the mount and the other items that need to go on the firewall so rather than guessing / trusting Van's on where things should go I decided to tackle the engine mount.First I enlarged the two upper corner pilot holes to almost full size. Then I used a 3/8" reamer to finish up one of the corner holes. I then installed the engine mount and first bolt. Then I used the other upper corner hole in the engine mount itself to do the final 3/8" reaming for that hole and installed the second bolt. The hardest part was drilling through the steal corner brackets mounted on the inside of the firewall.The four remaining holes were drilled and reamed using the holes in the engine mount as a guide. These holes were a bit more difficult to drill since I couldn't really step them up from smaller holes to the final hole sizes. I used a full size drill bit instead so it wouldn't chatter in the engine mount holes as I drilled through the stainless steel firewall, the aluminum reinforcement angles, and the steel corner brackets. The drilling/reaming oil helped but this was a lot of material to drill a 3/8" hole through in one shot. All of the holes came out great and there were no edge distance problems.I torqued the 4 corner bolts/nuts to 185 in-lb's and installed the cotter pins. I'll have to order some washers and longer bolts for the lower center two holes.
