I purchased a used Cherokee with an OS .46LA on it.
When I started it up I could see the engine had some movement when throttling up.

I removed the engine and there is a crack in the firewall running from the bottom up through where the blind nuts are.

Can the pastic top half of the fuse be removed for access? How is it held onto the bottom half? I removed some already peeling " tape " from the wing forward and it looks like that was all that was holding it together? Not sure what I'll find if I peel all the way back towards the tail?

I was thinking of 1/8" ply epoxied over the front of the existing 1/4" ply firewall. then remount the engine mount through both plys into the original blind nuts.

Without removing the top of the fuse it would be difficult to reinforce the firewall from behind?


Steve

If the firewall has been fuel proofed you may have a problem......as the wood has already been epoxied you won't get good penetration from the new epxoy........if that's the case it would be best to replace the firewall......
If it hasn't been fuel proofed then the 1/8 ply would probably be ok....
You ought to call the people you bought it from and tell them they can have their plane back...or reduce the price...of course they don't have to do either....
good luck on your fix</p>

Do you know what type of cherokee it is? I have the great planes cherokee shownin the link below and the top plastic canpy covmes right off by removing one screw on each side of the fuselage. See Link This will allow you access to the back side of the firewall.

http://www.greatplanes.com/airplanes...-cockpit-2.jpg

Must be a different cherokee.
on this one the plastic top half of the fuse runs the entire length of the fuse.

Steve

I am sorry I cannot help you much then. I am pretty new to all of this myself.

Just a thought, and I would defer to someone with a great deal more experience thanI have, but I wonder if you could epoxy the 1/8 ply to the front of the existing firewall, and then use several small screws to help hold it in place to compensate for the weaker epoxy bond between the fuel proofed wood and the new ply. I would think that with the bolts for the motor mountsandwiching it all together that thiswould be pretty strong. Again (Disclaimer) I am pretty new to this so I would default to more experienced flyers.

perhaps 4 small wood screws and some triangle stock at the sides would be ok......put the screws outside of the motor mounts.....I think you'd be ok...remember that will move your motor forward an 1/8 inch...