L inlet baffle issues

[Larry KMYA]

Just finishing the cowl baffling and my lower cowl inlets are 1/8-3/8” LOWER than the air filter/snorkel. This will not allow the inlet seal to be mounted as described in the plans (47-25). Anyone else have this issue?
My cowl is installed and fits well per the plans.

 

[Kyle Boatright]

It is probably easiest to drill out some rivets and tweak the geometry of your baffle ramps. That’s why it is a good practice to fit the baffles after the cowl so you can adjust them as you go.

 

[bjdecker]

@Kyle Boatright -- Spot on; Fit the cowl first, then worry about the baffles.

The cowl isn't setup correctly -- In your second picture, you can see the cowl is sitting about 1/16 - 1/8" low. Also, the cowl halves do not make a perfect (approximate) 12 3/4" circle at the front when mated; this is also seen in the second picture as the lower cowl "reveal" behind the spinner bulkhead is quite apparent.

The cowl height should be justified to the spinner O.D., not the rear bulkhead, the cowl mating needs to be adjusted to make a circle that is the same OD as the spinner aft edge.

 

[bjdecker]

@Kyle Boatright -- Spot on; Fit the cowl first, then worry about the baffles.

The cowl isn't setup correctly -- In your second picture, you can see the cowl is sitting about 1/16 - 1/8" low. Also, the cowl halves do not make a perfect (approximate) 12 3/4" circle at the front when mated; this is also seen in the second picture as the lower cowl "reveal" behind the spinner bulkhead is quite apparent.

The cowl height should be justified to the spinner O.D., not the rear bulkhead, the cowl mating needs to be adjusted to make a circle that is the same OD as the spinner aft edge.

View attachment 105357View attachment 105358

Yeah I know -- it's pink; the bad, really bad, years...

 

[rvbuilder2002]

The install instructions for the cowl are compensating for a bit of engine SAG that will happen initially.
Once that happens, the alignment of your inlet ramps will be spot on.

 

[rvbuilder2002]

It is probably easiest to drill out some rivets and tweak the geometry of your baffle ramps. That’s why it is a good practice to fit the baffles after the cowl so you can adjust them as you go.

Not all kits are the same…
The baffle kit for the RV 14 is all pre-punch and requires just riveting together and installing there is no adjustment.

 

[DanH]

I think he is OK for future sag (top cowl referenced of the top of the spinner), but the lower cowl needed edge trim to come up some. Too late now; hinges and nutplates are installed.

The install instructions for the cowl are compensating for a bit of engine SAG that will happen initially.
Once that happens, the alignment of your inlet ramps will be spot on.

Kinda tough to fit the inlet seal if a fella has to wait for the engine to sag.

 

[Larry KMYA]

I think he is OK for future sag (top cowl referenced of the top of the spinner), but the lower cowl needed edge trim to come up some. Too late now; hinges and nutplates are installed.

View attachment 105367


Kinda tough to fit the inlet seal if a fella has to wait for the engine to sag.

Thanks for the feedback. I can’t recall if I had the spinner on (probably not) when fitting the cowl top which would make it low the thickness of the spinner. Regardless, with the snorkel and baffles fixed it seems my only option is to modify the lip if the bottom cowl to bring it to the top of the air filter. So I can fit the baffle strip under the lip and over the filter frame.

 

[Dustyone]

Just finishing the cowl baffling and my lower cowl inlets are 1/8-3/8” LOWER than the air filter/snorkel. This will not allow the inlet seal to be mounted as described in the plans (47-25). Anyone else have this issue?
My cowl is installed and fits well per the plans.

I have seen this on 3 x RV-14's where the errors result in the problem you have.
Yours look really low so you may need to build up the ramp a little .

Rather than pull apart your baffle tin another option I have used on both RV-10 and RV-14's is to make the Baffle Rubber removable.
It makes cowl removal easier and cleaner look.

Place the new baffle rubber with the .063" alloy retainer on top of the cowl ramp, match drill through cowl and attach nut nutplates underneath.
Use Sika to attach the rubber to the retainer.
Glass in a small transition ramp .

RV-14A

RV-10

 

[Larry KMYA]

I have seen this on 3 x RV-14's where the errors result in the problem you have.
Yours look really low so you may need to build up the ramp a little .

Rather than pull apart your baffle tin another option I have used on both RV-10 and RV-14's is to make the Baffle Rubber removable.
It makes cowl removal easier and cleaner look.

Place the new baffle rubber with the .063" alloy retainer on top of the cowl ramp, match drill through cowl and attach nut nutplates underneath.
Use Sika to attach the rubber to the retainer.
Glass in a small transition ramp .

RV-14A

RV-10

Excellent suggestion. I won’t have to be a fiberglass artist and reshape the entire inlet and as you indicate it will be easier to remove.

 

[Larry KMYA]

Excellent suggestion. I won’t have to be a fiberglass artist and reshape the entire inlet and as you indicate it will be easier to remove.

Do you have a link to the Sika adhesive you used?

 

[Dustyone]

Do you have a link to the Sika adhesive you used?

Sika 295UV is my preference but many others will work.

 

[Halleffect]

Just finishing the cowl baffling and my lower cowl inlets are 1/8-3/8” LOWER than the air filter/snorkel. This will not allow the inlet seal to be mounted as described in the plans (47-25). Anyone else have this issue?
My cowl is installed and fits well per the plans.

Yours is about where mine started, too. On the air filter side I found that the intake snorkel was pushing up the baffle some. Cutting another 1/8" off of the snorkel at the fuel servo end dropped the air filter about 1/8". The other 1/8" of an inch on that side and the 1/8" on the right side, as Scott says, I expect to settle in over the first 100 hours. For now, the seal/lower cowl is slightly lower than the cowl baffle but still sealing the gap. As far as the corners go, that just takes a fair amount of building up, cutting back and reshaping the cowl inlets to match the corners of the engine baffling.

 

[Larry KMYA]

Is yours the EXP-119 model? My snorkel enters the throttle body horizontally so cutting there won’t help. The outer edge of the engine baffle at cylinder #2 is vertical and has no flex at all. The whole assembly is solid as a rock. I think putting the seal on the top side if my inlet is the best solution. My mistake was not setting the top cowl with the spinner on….
I don’t think it’s worth spending the money for and time for an entirely new cowl ing assembly.
Thanks for everyone’s input.

 

[Kyle Boatright]

Not all kits are the same…
The baffle kit for the RV 14 is all pre-punch and requires just riveting together and installing there is no adjustment.

90 minutes, a few drilled out rivets, a bit of 0.032 from the scrap bin and it would mate up just

 

[Halleffect]

Is yours the EXP-119 model? My snorkel enters the throttle body horizontally so cutting there won’t help. The outer edge of the engine baffle at cylinder #2 is vertical and has no flex at all. The whole assembly is solid as a rock. I think putting the seal on the top side if my inlet is the best solution. My mistake was not setting the top cowl with the spinner on….
I don’t think it’s worth spending the money for and time for an entirely new cowl ing assembly.
Thanks for everyone’s input.

Yes, an EXP. It might not seem like it, but if the snorkel is too long at the fuel servo it will push up on the baffle at the air filter. Again, in my case it was 1/16-1/8" but it helped. Like Scott said too, you're not far off once the engine drops 1/8". I'd say mine settled in maybe half of that at twenty hours. Otherwise, build up the inlet and carve away the bottom side. You'll do a fair amount of that to get the corners to match up perfectly anyway.

 

[DanH]

I'm good with glass. I like glass. But I would not try to move those inlets to fix this problem. For sure I wouldn't fix one. They'll name your airplane 'Winky".

Sorry, but the lower cowl fit is poor. A nice RV-14 is a $300K piece, but an ugly one is considerable less. Rather than paste on a band-aid, bite the bullet and just rework the cowl so it fits correctly.