engine mount alignment

[shiney]

Today I decided to put the engine mount on the fuse. I cleaned the holes out with a 3/8 drill and drilled out the top two pilot holes (QB fuse) on the fuse. When I matched the mount up to the fuse the holes did not align. Now this is a QB fuse so the fuse holes were pre drilled, I now cannot drill out the bottom two in fear of causing more problems Where has it gone wrong and what can I do to rectify it?

Shiney

 

[yakdriver]

Here is the sequence to follow for the engine mount. First of all get a 3/8 reamer as a drill bit is too course and tends to elongate the holes. As you can see the holes in the firewall are drilled under size. Ream out the holes on the engine mount first. Then start with the upper right hand corner and drill with a 23/64 drill and ream the firewall hole. Hang the engine mount on that corner and get it leveled. Now with a 23/64 drill drill the lower left mount using the engine mount hole as a guide then ream both together with the reamer. Now bolt it down and you have the upper right and lower left corners holding the mount on. Now go to the upper left drill, ream and bolt then the lower right and finally the two lower middle mounts. When you are done the bolts will all have a precise passive fit. One other thing I do is drill all of the bolt holes one size under and ream on everything. That way everything fits perfectly with no slop. Very important on things like mounting the stabilizer. Don

 

[alpinelakespilot2000]

Today I decided to put the engine mount on the fuse. I cleaned the holes out with a 3/8 drill and drilled out the top two pilot holes (QB fuse) on the fuse. When I matched the mount up to the fuse the holes did not align. Now this is a QB fuse so the fuse holes were pre drilled, I now cannot drill out the bottom two in fear of causing more problems Where has it gone wrong and what can I do to rectify it?

Shiney

Your instructions should say to use the mount as the drill guide, since not all welded mounts are exactly the same. You cannot just drill the pilot holes in the firewall up to full size.

The instructions Don gives above would work great if you hadn't drilled any holes yet. However, since you've already drilled two holes without the mount on, I'm not sure what you can do at this point, but you probably need to call Van's. It looks like you'll need to do a signficant modification. Good luck and hang in there.

 

[rph142]

I made the same mistake on my 3. I ended up just replaced the upper steel brackets. Its really not a big deal because the firewall does not offer structural support between the engine mount and steel brackets. After receiving new brackets it took about 5 hours to fix. Good luck.