I have a major increase in air flow , pressure(relieved by relief valve), and noise when I select cabin heat or defrost air.  Should this air be reduced by venturis in warm-side pressure hoses from the intecooler?

 

Thanks,

Tim

LNC4,  N524JG

Tim, in working over the intercoolers and baffling system on my Lancair prepared TSIO-550 I found that the sonic venturis that were on the "hot" side of the intercoolers were installed backwards.  The sonic venturi should be found attached to a nipple that comes off the input side (aft side) of the intercooler.  It would be possible to either leave these out or turn them around backwards.  I don't know the effect of turning them around.  I never flew with it installed backwards.  Here are a couple of images of the sonic venturi.  Some of the sonic venturis have an arrow scratched onto them to show flow direction.  The image here has the sonic venturi installed BACKWARDS. I have also attached a drawing to show the correct orientation for flow.  In order to know which way they go, you must either have an arrow on the venturi or take them off entirely to visualize the internal contours to get the orientation right.

Barry Knotts
LIV-P, Conti TSIO-550