CH 701 912 ULS Cooling

Now that summer is here in Idaho and I want to fly on the really hot days - sadistic - I wonder what those of you out there have done to increase the cooling air through the cowl by adding a "lip' at the rear bottom edge.

I have molded a ram air scoop for the water radiator inlet and also built a scoop for the NACA duct. There was a little imrpvement - about five to eight degree drop -but wondering how the "lip".

on the cowl bottom works.

Any thoughts on this would be appreciated.  Attached a pic showing both of my scoops..

ttfn

Phil Smith

Views: 363

Attachments:

▶ Reply to This

Replies to This Discussion

Permalink Reply by François Balaux on June 6, 2016 at 9:27am

Hi Phil

From past experience I think you will have more improvement by working on getting the air out of the cowling. If if can't get out the pressure will raise and fresh air won't get in.

Did you trim the cowling around the gear leg?

Regards,

Francois

Permalink Reply by Phil Smith on June 6, 2016 at 9:53am

I haven't done anything to the bottom of the cowl.  Do you or anyone else have experience with modifying the outlet area.  The setup is a Zenith FWF with a rotax 912ULS as supplied from the factory.  I have seen mention of the lip idea...in fact it has a service kit for some older 172s.

The problem is not a show stopper just an aggravation on 95 plus degree days.  The oil and the head temp creep into the yellow - thought if there was an easy fix I'd try it.  All I'm looking for is about five to ten more degree reduction.

tnx

Phil

Permalink Reply by François Balaux on June 6, 2016 at 10:27am

I have not modified my 701. As I live in Quebec City, Canada I have to block about half of the radiator with a plate most of the time to have correct temperature.

However in the assembly guide, cowl section, there is a note : "NOTE: Wait to trim outlet till flight testing. Trim away the bottom cowl as required for proper cooling."

I had to fix a few cooling issues on industrial electronic/mechanic stuff and it is always easier to work on the air exhaust than the intake. 

Regards,

Francois

RSS

New from Zenith:

Zenith Planes For Sale 
  

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith:

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Zenith Homecoming Tee:

Zenair Floats

Flying On Your Own Wings:
 A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

Aircraft Insurance:

 
 

West Coast USA:

 
Pro Builder Assistance:

 

Transition training:

Lavion Aero

K&S Aviation Services

Aircraft Spruce & Specialty for all your building and pilot supplies!

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

© 2024   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service