Louw is absolutely correct on the use of beam mounts. My choice of words "old fashioned" was poor. I too design and build airplanes with beam mounts. Oak and Maple are the only two acceptable woods for beam mounts. If the model you bought was designed for beam mounts then by all means use them as directed. My comments were directed mostly at ARFs which almost always have firewall engine mounts. The choice of engine mounting styles is usually left to the designer or builder. Nothing is engraved in stone and as you can see from the comments the differences all have advantages as well as advantages.