I've received Vans latest firewall enhancement kit but haven't seen a service bulletin or anything explaining why they think this is necessary. I bought it because it was inexpensive($25), not because I know it is needed. Anybody know of hard evidence of the firewall needing help? Ken
Van's Air Force
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RV-12 Firewall Reinforcement Kit
- Thread starter keny
- Start date
I've almost finished installing mine. The modification clearly adds extra strength and stiffness, particularly between the fuselage sides and the horizontal firewall panel. I'm not sure what prompted Vans to provide the upgrade, but if they think it's a good idea, then so do I.
I do recall that one builder reported some cracking in the forward fuselage skin about a year or two ago, so that may have had something to do with it. This fix would certainly relieve the stress concentration in that area. Others have also reported vibration in the firewall area.
The most difficult problem I encountered was trying to remove the tough bead of firewall sealant from under the horizontal firewall so I could get the sidewall stiffeners to fit properly. Getting the gascolator off took a lot tugging too, and getting the safety wire back into those screws won't be a fun job.
I also left out those rivets in the front firewall stiffener that would have gone directly into the stiffener beads pressed into the firewall. There is a gap between the stiffener angle and the bead, so installing a rivet there seemed like a bad idea.
I do recall that one builder reported some cracking in the forward fuselage skin about a year or two ago, so that may have had something to do with it. This fix would certainly relieve the stress concentration in that area. Others have also reported vibration in the firewall area.
The most difficult problem I encountered was trying to remove the tough bead of firewall sealant from under the horizontal firewall so I could get the sidewall stiffeners to fit properly. Getting the gascolator off took a lot tugging too, and getting the safety wire back into those screws won't be a fun job.
I also left out those rivets in the front firewall stiffener that would have gone directly into the stiffener beads pressed into the firewall. There is a gap between the stiffener angle and the bead, so installing a rivet there seemed like a bad idea.
edward7048
Well Known Member
RV-12 firewall reinforcement kit
what is the part number for this kit?
what is the part number for this kit?
PN# 12 Stiffener Kit
txaviator
Well Known Member
Joe,
I installed mine yesterday before hanging my engine. So I can't help with photos of the kit itself. But it's just three simple pieces of aluminum angle. I'll take pics of the installation later, to give you an idea of where they all mount.
DonFromTX
Well Known Member
Go to Torstens site here: http://torstensrv-12.blogspot.com/ and go back a few days, many photos of items and installation.
TomVal
Well Known Member
Don,
It sounds like you are planning to comply with the oil tank mounting bracket SB. Does the Honda engine install require an external oil reservoir? I decided that this SB did not apply to our Jabiru install since it was not supporting the weight of a reservoir and oil. Am I missing something?
Regards,
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joedallas
Well Known Member
Firewall suggestion ?
I think you are mixing up a service bulletin And a firewall reinforcement suggestion ?
firewall reinforcement suggestion ?
I think you are mixing up a service bulletin And a firewall reinforcement suggestion ?
firewall reinforcement suggestion ?
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DonFromTX
Well Known Member
No oil tank mounted there, and you are correct, much of the reason for the kit does not exist.
That said, I AM interested in the "inside portion" of the stiffener, I feel that is a weak spot and could use the kit for extra support. I don't feel that with the lack of an oil tank, we will have the firewall drumming problem.
That said, I AM interested in the "inside portion" of the stiffener, I feel that is a weak spot and could use the kit for extra support. I don't feel that with the lack of an oil tank, we will have the firewall drumming problem.
joedallas
Well Known Member
Stiffing bead ?
Thanks Don
I don't like the angle going over the stiffing bead in the firewall.
I will handle this in a different way.
Thanks Don
I don't like the angle going over the stiffing bead in the firewall.
I will handle this in a different way.
For builders that have firewalls with continuous stiffener beads, the kit is supplied with spacers for the angle that allow for the height of the stiffener bead.
TomVal
Well Known Member
I think you are mixing up a service bulletin And a firewall reinforcement suggestion ?
Thanks Guys...
Now I get it. I missed the fact that the firewall stiffener kit wasn?t listed on Van?s site as a Service Bulletin, Notification, or Letter and was a separate issue from the Oil Tank Mount Brackets. Us non-builders get easily confused
Regards,
txaviator
Well Known Member
Yes, I think folks got a little confused....there is a kit that Van's sent out no charge, that stiffens up the oil tank bracket. This is simply a new rib installed into the bottom of the existing oil tank bracketry.
On the optional $25.00 stiffener kit, there are three pieces of angle. One goes firewall forward, and as Scott mentioned, it has 'stand-offs' that are riveted to the firewall stiffener that make it to where it doesn't touch the continuous strengthening bead that is pressed into the firewall (my firewall has the continual bead- others may not?)
The other two pieces of angle are riveted to the inside of the fuselage and extend up to the front, ending under the 'shelf' at the front end. I can see where the interior kit WILL need to be modified to accomodate this new angle on each side. I'm guessing Abby is aware of this optional kit? If so, I am sure she can easily design new side pieces to accomodate the two pieces of angle.???
txaviator
Well Known Member
Nope, you didn't miss anything. I installed the new piece to the oil tank mounting bracket, although it may not have been needed since we won't have the oil tank mounted there (with Jabiru's). We are essentially cutting the front half of that bracket off anyway (or in your case, Pete cut it off). Since I had yet to hang the engine, it took all of 3-minutes to install the piece that Van's sent, so I went ahead and did it.
You should be A-OK.
gblwy
Well Known Member
FWIW I installed this kit as I was the person with a crack in the firewall, and had previously identified the drumming sound as coming from the firewall as the metal gets hotter during engine warmup. I stop-drilled the crack a year ago and have had no further extension. I also now run up the the engine at 2700 with is just above the resonant frequency.
I had planned to glue a spruce stiffener on the cockpit side of the firewall when Vans released their stiffener kit. I have now implemented the Vans fix. It still seems as if the firewall may vibrate, though haven't run the engine yet.
One of the drilled-out rivets on the fuselage stiffeners also impacted the fix I made a year ago to a crack that had developed on the port fuselage skin (assumed to be due to the cowling vibrating against the rest of the structure), and aslo not extended once I had filed some material off the cowling.
Two other issues come to mind, the first being the impact on the trim (previously noted), and the second being the four holes left in the firewall as a result of truncating the previous stiffeners. Of course I may have done this step incorrectly, as the plans were (unusually) a bit vague. Whatever, I filled the four holes with dummy rivets, then covered the firewall side of these and other rivets with grey/black gunge.
Cheers...Keith
I had planned to glue a spruce stiffener on the cockpit side of the firewall when Vans released their stiffener kit. I have now implemented the Vans fix. It still seems as if the firewall may vibrate, though haven't run the engine yet.
One of the drilled-out rivets on the fuselage stiffeners also impacted the fix I made a year ago to a crack that had developed on the port fuselage skin (assumed to be due to the cowling vibrating against the rest of the structure), and aslo not extended once I had filed some material off the cowling.
Two other issues come to mind, the first being the impact on the trim (previously noted), and the second being the four holes left in the firewall as a result of truncating the previous stiffeners. Of course I may have done this step incorrectly, as the plans were (unusually) a bit vague. Whatever, I filled the four holes with dummy rivets, then covered the firewall side of these and other rivets with grey/black gunge.
Cheers...Keith
I haven't got the plans handy at the moment, but filling those four unused holes with rivets and sealing all the rivets is mentioned somewhere.
txaviator
Well Known Member
Yes, the two holes on each side are called out to be filled with LP4-3 rivets, then sealed with fuel tank sealant on the FWF side.
