J

Jedtek

Member
I'm about to start fitting a Van's filtered airbox to my 0320 RV-4. Mine was originally built without a filter. I'm not sure if I can mount the new intake in the centre of the lower cowl or does it have to be off to one side? The original intake is offset but I can't see why it has to be like this. It looks like the new intake is slightly offset. Any input on how to do this and save me time and heartache would be great.

Thanks
 
Hi Jed...

....My friend has a -4 in my hangar and the FAB is offset so it nestles in the also offset lower cowl. The carb is offset so this has to be.

With both top and bottom cowls off, either cleco or duct tape the FAB in place and lift the lower cowl and see how it accomodates the FAB. This is a real trial and error deal, no quick way.

Regards,
 
Jed, built correctly from new it does all fit....just. As Pierre says everything is a little offset. In fact quite a bit. See the last picture here. One thought. If yours was built without a filter from new it would have been possible for the builder to lift the lower cowl a little resulting in you not having the room you need. I doubt that is the case though because a circle behind the spinner and the match of the lower cowl to the fuse below the firewall control that height.

My guess is it will be all right....just. Steve.
 
Thanks Pierre. You know, every little bit of info helps when starting something like this. I thought it was offset but it just seemed possible to fit it otherwise! I went to the hanger earlier today and bolted the top plate to the carb after a few mods had to be done and will now try the lower cowl for clearance. Steve, thanks too for the photo. Seeing it helps a lot. I have the weekend to play with it, I hope it all works out!
 
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Air box progress...

...Well, after spending a day cutting and fabricating my cowl and new airbox, I think it's looking about right. I looked at the carb again and it really is pretty much in the centre of the engine/airframe.

3740116293_5b7a15bc3e_o.jpg


The airbox is tight to the lower cowl when in position but I think I can improve on that.

3740116385_22ccdcf76b_b.jpg


After trying the new intake in various different positions on the lower cowl, it now is only very slightly offset. The old intake was far more offset than this new one will be. Does the offset have anything to do with airflow or propwash (as well as carb offset), as someone mentioned to me today? Thanks again for all your input!
 
Jedtek;343873 After trying the new intake in various different positions on the lower cowl said:
The whole front of the engine is offset to the right of the airplanes center line. It's to offset that spiral propwash.

L.Adamson --- RV6A
Click to expand...
 
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