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Kitfox IV with a VW engine

Posted By:
Brian Rex
#1 Posted: 9/14/2009 23:01:04

I would like to build a Kitfox IV (I know where I can get an unbuilt kit) and put a VW derivative engine in it.  Aerovee, Great Plains, Revmaster, etc.  However, before I do, I would like to talk to someone who has actually done it.  Anyone out there with a model IV and a VW engine?

Peter Thomas
Homebuilder or Craftsman
#2 Posted: 9/18/2009 17:40:23

In Australia I flew a certified ultralight version of the Kitfox, called the Skyfox. It was powered by a VW derived engine and flew very well. I believe it was 1915 cc,with electric start and alternator etc.

Remember though,  this was an early very light version of the Kitfox, not loaded down with options and heavy avionics.

Mark Scott
Homebuilder or Craftsman
#3 Posted: 9/21/2009 07:30:00

The definitive source for Kitfox info is the Matronics Kitfox list.  The link is here:


There have been a few people who have gone the VW route.  You should be able to search the list at the above address and find the info you're looking for.  In general I would say that it sounds like it's possible, but you will have to engineer the installation carefully to get adequate cooling, and your ship needs to be lifht. 

Kristine Bennett
Homebuilder or Craftsman
#4 Posted: 9/26/2009 22:07:30

The one thing you may want to do if you use a VW motor is out a Re-Drive on it. That way you can put a large prop on it and spin the motor up so it can make power. VW type one motors do not like to be lugged, they are happy to be spun at 3500 to 3800 RPM all day long.

The Valley Engeneering re-drive is one of the simplest and lightest out there. They started out life as a drive system for swamp boats and they get used hard and put away wet and surive.


remember KISS, Keep It Simple Stupid as well as add lightness to what you are flying!
Jon McDonald
Homebuilder or Craftsman
#5 Posted: 9/26/2009 23:21:14

Also, check with the matronics Zenith 701 lists, as well.  the 701, although it is metal, is the same size as the Kitfox IV, and is also a STOL bird.  Several folks have used VW conversions on these planes with different results.  In addition, call Steve Bennett at Great Plains.  I know that he was selling VW firewall Forward packages for other Kitfoxes (I-III maybe?).  He is a straight shooter and will tell you whether one of his products is a good fit for your aircraft, even if it costs him a sale.

Jon McDonald Building Sonex #1287