FAB and AFP injection

[RVG8tor]

I am starting the FAB install. The top mount comes with a hole that you use as a guide to install the top mount to the thick plate that would attach to the fuel control with bolts. This makes a pivot point that you then use to rotate the top mount to get FAB lined up with the scoop inlet. Well the AFP injection has a compression ring so the entire FAB can be rotated.

My question with the long explanation is did you use this hole? What I have done so far is fit using the hole but I set it up so that there is no edge distance issues for the holes that will get drilled for the nut plates in the top mount. I am then adjusting the position of the ring (rotating) to get the final fit to the inlet. If the hole was not already there I would drill the plate to the top the mount centered and then just use the rotation of the AFP mounting ring to position to the inlet. So anyone using the AFP injection, I would appreciate knowing if you used this hole or not. If I center the plate then this hole is left open which does not seem like a good idea.

Cheers
Mike

[N427EF]

Mike,

I have installed an AFP system on 2 airplanes and centered the plate first then rotate around the clamp ring to get it lined up with the intake.
The AFP system is somewhat of a luxury when it comes to convenience, not only to get it lined up with the intake but also when it comes to hooking up your mixture arm. Other systems require a cutout on the FAB to accommodate the arm where as the AFP mixture arm does not interfere with the FAB box.
Lastly, you will make the final transition from the intake of the cowling to the FAB and any minor misalignment can be corrected in the fiberglass transition.

[RVG8tor]

Originally Posted by N427EF

Mike,

I have installed an AFP system on 2 airplanes and centered the plate first then rotate around the clamp ring to get it lined up with the intake.
The AFP system is somewhat of a luxury when it comes to convenience, not only to get it lined up with the intake but also when it comes to hooking up your mixture arm. Other systems require a cutout on the FAB to accommodate the arm where as the AFP mixture arm does not interfere with the FAB box.
Lastly, you will make the final transition from the intake of the cowling to the FAB and any minor misalignment can be corrected in the fiberglass transition.

Oh well, I used the pre-punched hole. I tried fitting with the plate centered but I make the left side of the FAB a bit close to the side of the cowl it seemed I had more room by letting the plate rotate a bit using the pre-punched hole. It looks like it will work just fine, I should be doing the layup for the transition to the FAB mouth tomorrow.

I am not certain why this pre-punched hole is there, after I did all this I notice that the hole is there in the diagram of the nut plates but not used for one of the nut plates. I hate when I over think this stuff.

Thanks again

[N427EF]

The good news is, there is quite a lot of room for adjustments in all directions
and not really a down or upside to getting it done one way or the other.
Keep going you are almost there.

[RVG8tor]

Thanks Ernst for that bit of motivation you are right. I realized that Monday some oil lines come in; those and hooking up CHT and EGT wires and my engine stuff is mostly done. Still need to rivet the baffle seal on but an engine start is not far off in my future, not to mention a first flight.

I guess I better get the paper work off to the FSDO, the DAR said 3 weeks would be a good lead time for him. Lots to do still, test fuel system W&B, final once over everything.

I can only hope summer lasts a little longer here in the NW, I can see me passing the inspection then having 3 straight weeks of rain! Oh well she flies when she flies. It is nice to realize that next year I will be flying to all the big shows.

Cheers