RV-7/7a Plan Gottcha's

[wirejock]

Here's another small Gotcha. Photo=1,000 words
The C-670 Bushing is pressed into VA-165 Mixture Bellcrank.
When the bellcrank is bolted to VA-164 Mixture Bracket, it doesn't freely rotate unless the bolt is left loose enough so it rotates. The result is friction against the flanges. Not correct in my mind.
The bushing should be captured by the bolt between the flanges so the bellcrank can rotate freely on the bushing.
Maybe not the correct fix, but I drove out the bushing. Then the Mixture Bellcrank was reamed to 3/8" and polished. A tiny bit was removed from each side of the bellcrank so the bushing was a few thou wider. A bit of Lubriplate applied. Slip the parts back together. Now when the bolt is tightened, the bellcrank rotates either way freely.
Yes, I scratched it a little. I have touch up paint.

Edit...
Ditch the Vans bushing. Every time I reassembled and tightened the bolt, the bushing swelled and the bellcrank froze up. Go to the local hardware store aviation department and but a steel spacer bushing. I got one 1/4" ID X 3/8" OD and almost exactly the right length for less than $2. A little sanding and polishing and the bolt can be torqued to spec. Bellcrank rotates like butta!

[riseric]

Originally Posted by wirejock

Yes, I scratched it a little. I have touch up paint.
Attachment 10659

Good catch Larry!!!
Don't worry about the scratches, how many times do I have to remind myself that I'm not building a 35000$ Swiss Watch...
...wait a minute... my project will cost way more...
It won't show at cruise speed and altitude...

[wirejock]

Originally Posted by riseric

Good catch Larry!!!
Don't worry about the scratches, how many times do I have to remind myself that I'm not building a 35000$ Swiss Watch...
...wait a minute... my project will cost way more...
It won't show at cruise speed and altitude...

Doesn't bother me. That's for the builders that always comment about stuff that doesn't matter just to point out the mistake. Figured I would save them the effort.

[motodave]

Quick question, I'm also using a VPX will not be using the Garmin supplied shunt on the B lead... wonder what I want to measure with it? Thinking battery state charge / discharge, ideas? Single B&C 60a in my case.

[motodave]

Looks like I get to move my throttle cable mount over... installed per Van's with stock exhaust on I(O)360-M1B...

Untitled by Dave Hock, on Flickr

Untitled by Dave Hock, on Flickr

This is too close and can't really even get the heat shield in place. I will attempt to flip the bracket over as others have done.

[RV74ME]

Originally Posted by motodave

Looks like I get to move my throttle cable mount over... installed per Van's with stock exhaust on I(O)360-M1B...

Untitled by Dave Hock, on Flickr

Untitled by Dave Hock, on Flickr

This is too close and can't really even get the heat shield in place. I will attempt to flip the bracket over as others have done.

Something else to keep an eye on Dave is the two exhaust pipes where they cross underneath. Both mine and another -7 had made contact with one another and actually rubbed an oval shaped area. One of them rubbed all the way through and actually had a pin sized hole. Sent back to vetterman who took care of it.

[motodave]

Thanks for the tip Steve

[Iluke]

Dave-
I had a similar problem and made a new bracket o replace the one Vans sent. The new one elevated the came up closer to the sump. You can see in your pictures there is some space available above the cable now. I used that to give me more room off the exhaust.

I made the new bracket first as a template out of 032 aluminum in order to get my dimensions right (took 2-3 trys), then ordered some 4130 (I believe I used .062) and mad it from that.

I don't seem to have any clear pictures of it on hand but I will be at the airport this weekend and will take some if you like.

-Ivan

[wirejock]

Originally Posted by Iluke

Dave-
I had a similar problem and made a new bracket o replace the one Vans sent. The new one elevated the came up closer to the sump. You can see in your pictures there is some space available above the cable now. I used that to give me more room off the exhaust.

I made the new bracket first as a template out of 032 aluminum in order to get my dimensions right (took 2-3 trys), then ordered some 4130 (I believe I used .062) and mad it from that.

I don't seem to have any clear pictures of it on hand but I will be at the airport this weekend and will take some if you like.

-Ivan

I would love to see photos! Same problem.

[bjdecker]

Originally Posted by wirejock

I would love to see photos! Same problem.

Yup - same problem on my IO-360-A1B6; I also didn't like the angle/routing of the cable.

I did the same thing as prior poster -- make a new bracket out of 18ga 4130 plate. Move the cable hole over closer to the screw bosses and closer to the sump.