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Mixture firewall penetration (RV-7A)

Radomir

Radomir

Well Known Member
I searched the forum and did not find much *useful* info... You'd think everything's well covered by now :)

I'm converting from carb to F.I. (*vertical* induction) and need to figure out best place to drill a hole in the firewall for the mixture cable. (this is on my -7A) I am using the VA-182 bracket. Any suggestions? Would drilling a hole right next to the throttle work? Do you need a longer cable then (I have both on hand)

I have to consider a possible interference with the Weldon pump, which will be installed in same place as the old Facet pump (just different angle)..

Would love to see/hear what worked for you...
 
Thanks Don... saw those.. but it's definitely more challenging for us blessed with the nosewheel :) Your cable goes right through the area that's blocked by the nose gear socket on my plane..
 
I think Bob Collins went full circle on this issue so maybe he'll pipe in. I'm going to be in the same boat soon and curious what he and others ended up doing.
 
Vans recommended location works great and the length of the cable is just right for that location. It is about 4.5" from the top rivets on the FW and 10.5" from to the right of the left side of the FW. This is on page DWG 19

Mehrdad
RV7A - IO360M1B
 
Is that the one that's about 3" inboard of the prop governor cable? I saw that one, but I was under impression that one was for horizontal induction.. not vertical... I may be wrong though..

Can someone confirm?
 
I emailed you a pic of Dan C's firewall setup... I know it's a dragger but will be close.

-d-


Radomir said:
Is that the one that's about 3" inboard of the prop governor cable? I saw that one, but I was under impression that one was for horizontal induction.. not vertical... I may be wrong though..

Can someone confirm?
Click to expand...
 
dhall_polo said:
I've got some pics and notes that will be useful for you...

http://donka.net/gallery/rv7_engine?page=5
Click to expand...
Hi Don,

I installed my mixture cable the exact same way you did. I even have the same throttle body and my engine is the same color! :).

Did you have any issue with the cowling and the airbox? I heard some report that just bending the bracket resulted in the airbox not aligning with the cowling, although it sounds like a spacer between the airbox and the throttle body would solve that.

Thank
Vince
RV-7
 
n567vb said:
Hi Don,

I installed my mixture cable the exact same way you did. I even have the same throttle body and my engine is the same color! :).

Did you have any issue with the cowling and the airbox? I heard some report that just bending the bracket resulted in the airbox not aligning with the cowling, although it sounds like a spacer between the airbox and the throttle body would solve that.

Thank
Vince
RV-7
Click to expand...

Cool, another blue engine. I'm sure you'll find it is much more powerful than the gray lycomings. That's my story, and I'm sticking to it.

I have not had any issues in this area, now with ~110 hrs. IIRC, the Van's bracket is shaped assuming a reverse throw mixture control on the fuel servo. If you have that reverse throw servo you have to modify the airbox, essentially building a notch into it. If you have the servo with the forward throw mixture like mine, you *must* bend the bracket and no mods are required for the airbox. I think the forward throw mixture is the better configuration for the rv7 with vertical-io, but both work. Jamie Painter has the opposite mixture throw to mine, and both our planes are doing fine.

When you build up the airbox, the instructions take you through the process of aligning with the ram intake and the cowl sides. I more or less just followed those instructions, and it all worked out.

Good luck and post some pics of that engine!

Don
 
Cool. So you didn't need a spacer between the air box and the throttle body? I've been reading many people have needed to lower the airbox to get it to line up with the cowling inlet. Did you have the pink cowling, or an older one?

Is that an Aerosport IO-360-B1B like mine?

Geez. I think mine roll bar color is the same as yours too and I have the exact same step ladder! too weird.

Thanks
Vince
 
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