ORIGINAL: LarryQ
I thought about washers...but after tightening the mount...and given the vibration...I would think the washers would just "Sink" into the Wood of the firewall....
It would be much better to spread the load over a larger area...to insure the mount doesn't work loose over time.
Larry,
There are [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXE953&P=7]thrust plates [/link] made by Ernst. They make them according to the size of the engine/mount. Tower, yeah I said the dirty word, sells them for less then $3 each.
I have used the screw method myself and it works fine. But if you are having some reserve about them pressing into the wood I would suggest the thrust plates.