Skymaster Forum  

Go Back   Skymaster Forum > Messages
Register FAQ Members List Calendar Today's Posts

Reply
Thread Tools Rate Thread Display Modes
  #1  
Unread 07-25-11, 12:22 PM
rhurt's Avatar
rhurt rhurt is offline
Registered User
 
Join Date: Aug 2008
Location: Nashville
Posts: 80
rhurt is on a distinguished road
Normally Aspirated Skymaster Cabin Heat Shutoff?

Has anyone experienced problems getting the cabin heat in the normally aspirated models to completely shut off? Has anyone rebuilt the heater/ventilation control airboxes?

The changed the design of the control airboxes around 1970, and I wonder if the earlier design was prone to leak and if the later design solved the problem. Either way these things look tough to access.
Reply With Quote
  #2  
Unread 07-27-11, 07:56 AM
billsheila billsheila is offline
Registered User
 
Join Date: Oct 2006
Location: MA
Posts: 82
billsheila is an unknown quantity at this point
Yes they leak. I have found if you safety wire the control in the full closed position from underneath (and placard the controls "inop" in the summer months) it improves the situation. I think it was a bad design and air flow opens the flap slightly in flight, leaking warm air into the cabin. Also would be real bad of course if your mufflers ever failed...ie no way to really shut off the CO from entering the cabin.

Bill
Reply With Quote
  #3  
Unread 07-28-11, 02:20 PM
Aeromx's Avatar
Aeromx Aeromx is offline
Registered User
 
Join Date: Jun 2009
Location: Chatham, MA
Posts: 11
Aeromx is on a distinguished road
Easier than that & more effective, simply remove the muffler shroud to heat valve box orange SCAT air hose/duct during the summer months.
Reply With Quote
  #4  
Unread 07-28-11, 07:23 PM
billsheila billsheila is offline
Registered User
 
Join Date: Oct 2006
Location: MA
Posts: 82
billsheila is an unknown quantity at this point
Good suggestion. I asked my mechanic about that idea and he was not comfortable with that solution because of what to do with the lower end of the hose relative to it not getting caught up in the cowl flap. Or were you suggesting you remove it at the top end?
Reply With Quote
  #5  
Unread 08-03-11, 07:41 PM
rhurt's Avatar
rhurt rhurt is offline
Registered User
 
Join Date: Aug 2008
Location: Nashville
Posts: 80
rhurt is on a distinguished road
I took one of the mixing boxes off and found that the original design had no seals and the valve cannot completely shut off. They allow heated air in the cabin regardless of the control position. Go figure.

I bought some of the 1970's or later mixing plenums to install. They are cylindrical construction and have seals, so they should provide a much cooler ride. I have air conditioning in the plane now, but I sit up front and roast with the engine heat leaking in while the women in back are freezing.
Reply With Quote
  #6  
Unread 11-12-11, 03:48 PM
Aeromx's Avatar
Aeromx Aeromx is offline
Registered User
 
Join Date: Jun 2009
Location: Chatham, MA
Posts: 11
Aeromx is on a distinguished road
Quote:
Originally Posted by billsheila View Post
Good suggestion. I asked my mechanic about that idea and he was not comfortable with that solution because of what to do with the lower end of the hose relative to it not getting caught up in the cowl flap. Or were you suggesting you remove it at the top end?
Yes, totally remove the SCAT hose section at both ends so it does not hang loose. Save the hose and clamps to reinstall for cold weather.
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump


All times are GMT -4. The time now is 08:18 PM.


Powered by vBulletin® Version 3.6.9
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.