Estes Mini Bertha Clone, #TK-3, Part 4, Slightly Longer Engine Mount?

An engine block wasn't included in the original kit.

I added one, glued in so it's flush with the upper centering ring and body tube edge.

Here's why that engine hook was designed to hang 1/2" beyond the bottom of the mount!

There isn't much clearance and flex between the BT-5 and BT-20 tubes. The low bend of the engine hook scrapes along the outside of of an engine casing when slid into the mount.

It's not impossible to get the engine in the mount, you'll just have some friction when being slid into place.

I pressed the mount into place with the flat face of my sanding block. The Kevlar was fed out the back and layed to the side while pressing the mount into the tube.

The mount is certainly useable with the shorter overhang hook. 

TIP: This is a BMS 1 3/4" engine hook. The cut off ends were a little rough. I smoothed out the edges with a few passes of a small, flat diamond file. The engine slides in easier now.

With the Bertha's fin trailing edges in the way it takes a moment to work an mini engine into the mount.

I'm sticking with the modification I made.