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when start the cowling?

cgeyman

Well Known Member
Hi VAF braintrust. I just mounted my RV-9a engine, which is a carbureted 0-360, and am not sure when to start the cowling fabrication/mating. I haven't hung the exhaust pipes or fuel lines yet, or the baffling.

Is it better to finish FWF in the following sequence:

1. exhaust system

2. fuel lines with heat shielding and spacing from hot exhaust pipes as appropriate

3. baffling system and oil cooler

and THEN start the mating, trimming, and mounting of the cowling; with the spinner/prop attached for proper spacing?

Not sure if i should basically finish FWF engine systems before starting the cowl fabrication and fitting. what do you suggest?

Thanks!! (I am again carbureted, and standard build plans with Van's new elastomer nose gear mount)

Cal
 
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I think you want to install the cowl before the baffles. The rest probably won’t have much impact. Why cowl before baffles? ‘Cause you trim the baffles to match the cowl, not vice versa.
 
Cowl before baffles

You need the cowl fitted before baffles because the baffle cut is dependent on final position of the cowl. The other stuff can go either before or after but the cowl is easier to fit without the exhaust.
 
Vans recommends fitting the cowling with all this removed:

  • Exhaust
  • Starter
  • Alternator
  • Prop
  • Carb/Throttle body

Its just easier this way...less stuff to work around.
 
Vans recommends fitting the cowling with all this removed:

  • Exhaust
  • Starter
  • Alternator
  • Prop
  • Carb/Throttle body

Its just easier this way...less stuff to work around.

.... won't we need the prop on to set the gap to the spinner?

I haven't done this yet, obviously, and know there are special jigs/tools that can be had to help with this. I'm just curious the percentage of people who've fitted the cowl minus the prop.
 
.... won't we need the prop on to set the gap to the spinner?

I haven't done this yet, obviously, and know there are special jigs/tools that can be had to help with this. I'm just curious the percentage of people who've fitted the cowl minus the prop.

There are a couple of methods for setting the spinner backplate distance without the prop on. Vans recommends using pvc spacers that set the backplate the proper distance.

Having the prop on would be a real pain….
 
Last edited:
Howe jig

.... won't we need the prop on to set the gap to the spinner?

I haven't done this yet, obviously, and know there are special jigs/tools that can be had to help with this. I'm just curious the percentage of people who've fitted the cowl minus the prop.

Shoot me an e-mail. See below. I wrote a Kitplanes article. Not published yet but I can send you the draft. Also, reach out to David Howe. He sells a simple PVC jig to perform the entire cowl process. It's the neatest thing since sliced bread and worth every penny.
 
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