There has been a link on the Cowl/Cooling page entitled FransVeldman's Cowl for PH-DIY. That cowl was Frans original modification which proved unsatisfactory.
Frans continued to experiment and test and ultimately derived a cooling solution that performs well. I’ve not been able to contact Frans to ask him to write a detailed article, but this thread on Matronics describes his cooling system in detail along with notes from Paul McAlister concerning his similar effort ; http://forums.matronics.com/viewtopic.php?t=90686&postdays=0&postorder=asc&start=0
Frans message is #13. You need to study the entire thread for complete understanding, but to summarize, Frans has replaced the factory coolant radiator with a thin radiator, flush with the underside of the cowl with an adjustable cowl flap, replaced the factory oil cooler with a Laminova oil to water heat exchanger with a small oil cooler to reduce oil warmup time, rerouted the exhaust so the cowl opening for the exhaust pipe points to the rear and provided cylinder cooling air.
The coolant radiator is similar size to the one available from Rotax and used in many European 912 powered aircraft.
These two links have more photos and details concerning the coolant radiator.
http://forums.matronics.com/viewtopic.php?t=92940&highlight=cooling
http://forums.matronics.com/viewtopic.php?t=92913&highlight=cooling
As is evident from Frans notes and Paul’s comments, this is not a trivial modification but does seem to offer improved performance.
During our buld, we concentrated on ensuring that our radiators are well sealed to the cowling so that all air that enters passes through the radiators. With that, we do not experience cooling problems with our 914 powered XS monowheel in over 900 hours operation.
Jim & Heather Butcher
N241BW
