Replacing Engine Mount Extrusions

[swinn]

Decided to replace the extrusions on the firewall on which the engine mount is placed on the Long-EZ. The previous builder had drilled several non standard holes in this extrusion for a custom engine mount scheme that I'm not comfortable with.

 

The old pieces are now removed. I'll be using a heavier engine than was specified in the plans (360) so I'm going to put in steel angle instead of the plans specified aluminum angle. I read in a CP 86 (Oct. 1996) article that at least one person had experienced cracking of the extrusions with heavier engines hung on the aluminum. 4130 was used as a replacement.

 

Anyhow, the only way I can find to get 4130 angle is to make it out of 4130 sheet by way of a 90 ton bending brake courtesy of the local metal shop. Does anyone know if this is an acceptable practice? Should the metal be normalized after this operation? Would I be better off to weld up some angle from two pieces of flat 4130 and then normalize it? Thoughts appreciated.

[Fred N.]

I am also replacing the LEZ original mounts which held a souped-up 0-320. Aluminum is not good for heavier engines. I plan to use this new system designed by Art Bianconi:

 

This subject came up awhile back. Please go to this site

>>> http://www.computer-certainty.com/

>>>

>>> and click on the engine mount button and see what you think of this

>>> alteration from plans mount. Being a non-engineer it seems very much

>>> better than plans mount. Should other canards (ie Cozy MKIV)

>>> consider something like this to make a better mount? Post public if

>>> you wish.

>>>

>>>

>>>

>>> Jim Brewer

>>

>> Absolutely. This is an excellent solution.

 

Take a look. See what you think.

 

Fred N.

[Wayne Hicks]

The link didn't open up for me, but my suggestion would be to make the mount method identical to what the Cozies are using. My hangarmate is building a Long EZ with an O-320. He's happy with his modified Cozy mounting method.

[swinn]

Thanks for the replies. I've got the steel bent now and have asked a few metalheads about the bending, they say it isn't a problem. The 4130 steel angle should work good. I looked at my Cozy plans to see about copying that method of mounting, but my firewall is already in place and I would have to remove/rebuild it to duplicate the cozy method of engine mounting.