[RV_7A]

I just installed my engine mount and noticed with all 4 corners flush both of the bolts that go each side of the nose gear has a space. This one right near the fuel pump reinforcement is about 1/8". I removed the bolt and nutplate to clear the mount so there is no interference here but I still have the space.

This other side is about 3/32" from the firewall. My question is do I just use washers here or just tighten down the bolts?

Nice flush fit on the 4 corners like shown here.

Thanks Jeff

 

[dan]

Same here

Here's my setup, same deal: http://www.rvproject.com/20030409.html

)_( Dan
RV-7 N714D (743 hours)
http://www.rvproject.com

 

[RV_7A]

Well since I got to fly in that thing and it flew great I guess it worked

Thanks Dan!

 

[Davepar]

Same here. I made some .063 spacers with the fly cutter. I think that gap might be why the hole in the firewall didn't exactly line up with the nose gear bolt for me. The hole was a bit on the high side.

 

[RV_7A]

Excellent! Thanks guys!

 

[Kyle Boatright]

I had this issue on my -6 many moons ago. Van's said just to use bolt torque to pull the mount and firewall together.

Using a spacer such as a washer in a shear application (like the motor mount to firewall attachment) is a bad idea from a structural perspective. It adds a bending moment in the joint that you don't want.

KB

 

[robertahegy]

Dittos on what Kyle stated. It takes very little to pull the two together. Slight warpage of the mount and/or slight build irregularities most likely caused the slight bow. I just bolted it up tight and it is just fine.

Roberta

 

[osxuser]

But Dan's way is prettier . In all seriousness though, if you can shim the warpage out with washers, it will make it easier to remove the mount later (if you ever need to). The bolts will take a set in a lot hard on yours Roberta, not that that's a bad thing or anything, just ...different.

 

[RV_7A]

Since I have a choice here, I would rather use a spacer than have a constant stress on a chrome moly part. The mount is far more likely to crack over time from stress than these bolts are to ever "shear" off. I think in my situaton due to the space here that the washers are the way to go. Thanks for all the comments. Thats what is nice about this board, you get all kinds of recommendations and make your own decisions.