Originally Posted by Ironflight
Dave Anders has written a number of article on his R-4 speed and efficiency mods in Kitplanes Magazine - you can search for his name on the web site and find them.
I just looked up the links for a friend in Europe yesterday.
There is a THREAD on VAF also about Dave's airplane that points to a PDF file that Dave handed out at a Sacramento RVators meeting. The Sacramento RVators website is no more so the link is broken but I have attached a copy of the handout to this message.
Hope this helps.