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Cowl Misalignment With Inlet Ramp

Bootscooter

Active Member
Hi All,

I was pleasantly surprised that all you had to do to fit the lower cowl was to trim to the scribe line, some fine tuning with block sanding and it fit perfectly.

Except for one area and that is at the cylinder #2 inlet ramp, the cowl is about 3/16" blow the ramp. The top cowl and the prop spinner are aligned where they should be.

The fix for this would be to trim the cowl further back and fibreglass/flox/and make up a new rubbber ramp.

Just wondering if anyone had any pics of this process and how it turned out?
Rgs Chad

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Just heat the ride edge and flex it closer to the outside edge. Then mount your rubber flanges to fit over the edges of the air cooler and metal flanges.
 
mine was also high mostly o the inboard side. I tried making an aluminum ramp, but the engine movement at shutdown was extreme enough to either bend the ramp or fold the rubber material under. I'm thinking the only clean solution is to build up the cowl lower lip into a smooth ramp and raise the attachments for the rubber seal as well....

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Cowl Air Inlet Misalignment

I had the same problem with the bottom cowl as shown in your photo. The cowl lip and rubber was approx 1/4"plus below the air intake metalwork. So I built up a flox and micro ramp on top of the existing cowl ramp to match the height of the air intake . See attached 4 photos. (first time and dont know how to so hope they attach). Sanded to transition a proper curve, then used a dremel to remove the old existing fibreglass lip underneath leaving the new made ramp.

Regards
Greg Priest
Australia
RV14A (90% complete) Builder #140129
 
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Cowl Air Inlet Misalignment

I had the same problem with the bottom cowl as shown in your photo. The cowl lip and rubber was approx 1/4"plus below the air intake metalwork. So I built up a flox and micro ramp on top of the existing cowl ramp to match the height of the air intake . See attached 4 photos. (first time and dont know how to so hope they attach). Sanded to transition a proper curve, then used a dremel to remove the old existing fibreglass lip underneath leaving the new made ramp.
 
Interesting.

Just the other day there were several posts discussing the merits and pitfalls of the step-by-step instruction book for newer model RV's, vs the Big Picture presented by old school plans sheets. I don't have RV-14 material here in front of me, but with three identical reports, I'm guessing the instruction book has builders assembling complete engine baffles, then fitting the cowl in some later step.

Baffle kit text for older models is pretty specific. Here's an example:

Step 4 - Engine Alignment and Lower Cowl Installation
Before you begin the baffle installation, the engine must be in final alignment and the lower cowl must be installed. Other than light smoothing of the rough fiberglass edges, do not trim the lower cowl air inlet lip until you fit the front baffle air inlet floors. These areas should be trimmed together for accurate contour and gap clearance.


Reality is that many builders fit the cowl, then build the baffle ramps to match, using the baffle kit parts only as a guide. A lot of them get thrown away, and new, slightly different ones made. It is a mindset, one in which there is no expectation that any part is going to arbitrarily match some other part. In that mindset, everything is subject to tweaking for better fit, with trial assembly being the standard operating procedure.

I'm not knocking the new kits. The finished airplanes squeezing out the far end of the pipeline exhibit a more consistent quality level, and that's a good thing. However, no matter how well kitted the kits become, let's remember they remain hand-crafted custom-built airplanes.
 
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Port side lower cowl intake rebuild

I also had to rebuild the lower cowling air intake side to align with the forward elevation. This included cutting, fiberglassing cloth and micro-ballooning or closing, sanding etc to create the correct airflow. Their was a .5? gap down to the aluminum plate forward from the air filter leading to the snorkel.

We only I had to redirect the rubber forward under the fiberglass lip. The other RV builder had to do the same here in my town in western CO.. His is also working well and he has been flying for just over a year.

Bottom line is that the fiberglass lower cowl does not match engine and intake snorkel system. Not a terrible problem but took a extra week anyway & time figuring out the solution with my EAA tech advisor.
(Have pics but don?t know how to load them.)
 
I can do fiberglass pretty well, but would not do so here. Build new baffle tin to match the cowl, and keep the inlets symmetrical.
 
I'm looking at the possibility of trimming the top of the snorkel and re-installing the filter holder at a lower position, but there may be quite a bit of work to modify the sheet metal around the filter to match its new location.

Wondering if anyone has looked at this..
 
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