Engine Mount "gap" from Firewall

[smithhb]

I drilled my engine mount to the firewall today and after tightening up the four exterior bolts (left top & bottom, right top and bottom), the two lower bolts astride the nose gear weldment are both about 3/32" from drawing up to the firewall. Has anyone else seen this? Should I just "tighten it down" until the mount is snug against the firewall?

 

[cjensen]

This seems to be quite common Bret. Washers are needed to fill the gap. You don't want to tighten them down without...it'll put strain on the mount and probably pull on your firewall.

Looks like a couple of washers would do the trick.

 

[Kyle Boatright]

Brett, the RV-list archive contains a post from Scott McDaniels who says that you should use shims on the two interior attachment points if the four outside corners are in place but hand pressure isn't adequate to push the two interior mounting points in place.

Scott works in Van's prototype shop. When I'm looking for something in the archives, he is one of the people whose advice I gravitate towards.

 

[smithhb]

Thanks Chad,

Any idea what washer numbers would be best suited? It looks like I need AN970-4's.

 

[Mark Burns]

Make them out of aluminum sheet

Thanks Chad,

Any idea what washer numbers would be best suited? It looks like I need AN970-4's.

Bret,
I made mine out of .063 aluminum. I just made the outside square, and they look fine. You may need an .063 and .032 to get your 3/32".

Mark

 

[az_gila]

Round washers

Bret,
I made mine out of .063 aluminum. I just made the outside square, and they look fine. You may need an .063 and .032 to get your 3/32".

Mark

Or.... if you want round washers... just reverse the cutter in your fly cutter and make your own custom size washers... takes no time at all...

Just set the cutter for a straight inner side cut...

gil A - like my washers round....

 

[Frank Smidler]

Hardware store fender washers

I just went to the local hardware store and bought fender washers (large outside diameter). It is not necessary to use AN washers.

 

[smithhb]

All is well in RVdom. I fabricated two "square" washers out of .063 and it is solid as a rock. Thanks for the responses!

 

[cjensen]

That looks great Bret! I kinda like that better than big washers!