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FAB intake alignment (Spacer OK?)

AJ85WA

Well Known Member
Hi Guys

First of all, I am building a RV6 and the cowl is the older style where you need to attach the intake scoop yourself. My engine is a o-320 E2d and the carb is a Ma4 spa.

My problem is that when I have the scoop in the correct position the top plate of the FAB is 3/4" (18mm) higher than the scoop inlet. (I have noticed most builders end up lower:confused:


I believe the easiest way to fix this issue is to mill up a billet ali spacer to go between the carb and the FAB. In the picture I made a temp wood spacer to check what size I needed. (Is this ok? has anybody else done something like this?

DSC08582_zps50a1006b.jpg
 
That sounds like you might have an O-360 scoop rather than the O-320. The O-320 carb is about that much shorter than the O-360 carb.
 
360 scoop

Hi Doug

I did not know they were different but then I checked vans online and they do have a 320 scoop. Mine is written on 360:p

I still think I would like to use the 360 scoop incase I would like to upgrade some day.

Can't see it causing much more drag?
Would the spacer cause any problems? any comment would be greatly appreciated.

AJ
 
I believe the easiest way to fix this issue is to mill up a billet ali spacer to go between the carb and the FAB. In the picture I made a temp wood spacer to check what size I needed. (Is this ok? has anybody else done something like this?

exactly what I had to do. It is about 1/32 at the back and 3/32 at the front. I have a io-360 180 hp that required the shim to get it to match the cowl. I riveted it to the top of the FAB so it is not a separate piece.
 
The O-360 scoop is also required if you want to add fuel injection to the O-320 due to the servo length ( at least for the silver hawk). I doubt the larger scoop would add any significant drag.

I have no idea about the impact of such a spacer.
 
SPACER

I had to make a spacer for my O-320 when I switched from a standard carburetor to a Rotec TBI because the TBI unit was a about .75" shorter in height. I did not have any problems using a spacer. Instead of aluminum I used a piece to teflon and it worked out well.
80WD
 
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