Intake Ports for a Non-Piped Engine

[durabol]

I am trying to build a 100cc twin cylinder opposed/boxer style model airplane engine. Because this engine is design to direct drive a propeller the rpms are fairly low (around 4000) so a tuned pipe would be pretty long and I want to keep the design simple (avoid having to build a pipe and to keep the engine cool). I was wondering about the differences in the porting of a piped vs. a non-piped engine. Since this is a mildly tuned engine I have read about using a restrictive exhaust. Since I don't have a pipe to help with scavenging I was thinking that the boost port (port directly opposite exhaust port) should be smaller to prevent fuel from escaping but this is just a hunch.

Brock

[powerchute50]

Check out desertaircraft.com and their DA 100. Sounds just like your design. They have a bunch of different pipes and mufflers for that engine listed on the web site.

DonM

[durabol]

Yes similar idea although their engines puts out almost twice the power and are much lighter. The DA-100L has 9.8hp and only weighs 5.6lbs; my engine will put out about 5hp and weigh 15lbs.

Brock