I had a single backfire that blew the alternate air device off the bottom of the air cleaner housing, taking some of the fiberglass with it. So I installed an .032 aluminum plate on the bottom of the air cleaner using tank sealant, and it covers an area that is about .15" larger than the outside of the air filter, which also covers the hole where the alternate air device used to be. (I think it will provide a better seal at the bottom of the air filter than bare fiberglass (as designed) because the aluminum plate is perfectly flat.)
I noticed that the alternate air device was almost worn out after only 90 hours of engine time. The hole that the cover plate pivots around is elongated maybe 025" and the screw that the control cable pulls was worn about 1/3 the way thru where the control cable touches it. The control cable end was wrapped twice around that screw, and one turn of the wrap had broken off. This seems to be one of the weakest designs that Vans has done, and now I am wondering if I really want it, since it is so prone to failure.
Has anyone had any problems with the Vans vertical induction alternate air device?
Has anyone significantly improved this alternate air device? Like maybe putting a beaing in the pivot, or putting some sort of sturdy pivoting linkage for the attachment of the cable end for the control?
Has anyone ever USED the alternate air device on a vertical induction injected engine?. It seems that that only way that this device would be needed is if you fly thru precip and you were very close to freezing, such that evaporative cooling caused freezing of the moisture on the air filter, in which case a "carb heat" type of control would provide enough heat to thaw the air cleaner and restore full air supply to the engine. The advantage of the "carb heat" apparoach is that you can shut the control when you no longer need it, whereas the alternate air device requires a reset on the ground after landing.
I noticed that the alternate air device was almost worn out after only 90 hours of engine time. The hole that the cover plate pivots around is elongated maybe 025" and the screw that the control cable pulls was worn about 1/3 the way thru where the control cable touches it. The control cable end was wrapped twice around that screw, and one turn of the wrap had broken off. This seems to be one of the weakest designs that Vans has done, and now I am wondering if I really want it, since it is so prone to failure.
Has anyone had any problems with the Vans vertical induction alternate air device?
Has anyone significantly improved this alternate air device? Like maybe putting a beaing in the pivot, or putting some sort of sturdy pivoting linkage for the attachment of the cable end for the control?
Has anyone ever USED the alternate air device on a vertical induction injected engine?. It seems that that only way that this device would be needed is if you fly thru precip and you were very close to freezing, such that evaporative cooling caused freezing of the moisture on the air filter, in which case a "carb heat" type of control would provide enough heat to thaw the air cleaner and restore full air supply to the engine. The advantage of the "carb heat" apparoach is that you can shut the control when you no longer need it, whereas the alternate air device requires a reset on the ground after landing.