ORIGINAL: PowerHouse RC Performance

I have been looking at doing some case volume changes on some engines to see how they react. The one thing I do want to change if anything is the entrance angle at the port window. Alot of engine's cases make the the mixture turn a pretty sharp corner and then they enter at an up ward angle so I will be back filling the transfers to change the entrance angle but also increase velocity right at port entrance. Hopefully this will not only increase throttle response but also increase overall efficiency. The trick is getting a material that doesn't break down under heat and pressure. The oils in the fuel may cause the filler to detach but I have a couple ideas that I will be trying in the future. For the bigger engines, I was using Z-spar which is a two part epoxy used to repair boat hulls. It works very well as it cures very hard, is easy to grind on and doesn't break down with the fuels and oils used in most engines. The only thing it won't withstand is direct exhaust heat but that is pretty understandable considering it's chemical makeup. The trick is getting it to anchor and I usually did it one of two ways: 1.) Drill, tap and insert a screw in the casing for the epoxy to bite into or 2.) grind a few indentations into the material you want it to adheare to in a fashion that when dry, it can't pull away from or move in any direction. This will work good in areas such as transfers, boosters etc.

As far as the K5.9, I think they are are pretty well thought out design. They may not be made out of the absolute best materials in the world but they do run good stock, last awhile and with a race port, they wake up and haul the mail. Every engine has room for improvement and as long as you start out with a decent layout, you will get good end results.