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From:  n295vv [at] aol.com



well, the plot thickens.  you will recall  my comment last week-i was flying

to the homecoming, and the heater flapper valve was letting hot air into the

cockpit--lots of hot air?



i have an early IV.  there are two tubes welded on the back of the turbo

intercoolers.  they are there to bleed very hot compressed air from the

intercoolers and provide the hot air to heat the cockpit, hopefully during

cold weather.



this system has a flapper valve actuated by a push-pull cable to control flow.

i have noticed several things about it over a period of time:



1) at less than 31" it doesnt heat at all in the winter. (well, duh, the

engine is actually

        sucking air, not producing a higher than ambient pressure which can be

bled to

        the cabin--this has somehow escaped the attention of the folks at the

factory--

        no one at the factory could understand this--apparently they  never

have to use

        the heater in oregon.



2) it leaks hot air like crazy at all times at 31" plus-summer or winter



3) the leakage with the valve closed drops MP and reduces top KIA by 10 Kts--i

dont    

        even want to guess what the drops are when it is fully open.



4) since at less than 31" it doesnt blow hot air, i assume it is sucking

unfiltered                      

         cockpit air into the turbos



After talking about this problem with the factory, i have gleaned the

following information--the leaking flapper valve can be solved by replacing it

with a new tubular assembly for $400.  well, leave the leaking valve inline,

and add this to it.   ok.



the minus 31" problem?  Engineer--"well, we have never heard of this, are you

sure that this is happening?"   "well, yes, i am--do you want to talk to my

wife?"   "well, you could just connect it to a heat muff like we are using on

the ES."  "fine, i want to buy a heat muff."  "we dont sell heat muffs"

"where can i buy a heat muff?"  "i dont know."   and on it went.  i finally

decided i am going to weld up my own damn heat muff and disconnect the

plumbing from the intercoolers.  i dont have the foggiest idea of what heat

system they are supplying with the current kits--maybe it is still the system

i have--i saw an engine there with the tubes coming off the intercoolers.  if

so, a lot of people are freezing their hind ends off in winter.



am i missing something here?  am i the only IV pilot with the turbo bleed

system?  do you other guys have exhaust crossover pipe heat muffs?  if so,

where did they come from?  most importantly--have my wife and i got

alzheimer's, and only imagine that the system produces no heat at less than

31"?  please, please email me if this is happening to you also--i will cancel

my doctor appointment if i find i am not the only one.



and, oh, by the way, the homecoming was wonderful.  lots of good food, good

people, great looking planes, and wonderful weather.



david jones

pecatonica, illinois   n295 v v @ aol.com