What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Aft bottom baffle screw

RV7A Flyer

Well Known Member
Patron
I know I'm not the only one who has seen this (at least a few others on the field have noted the same issue)...

Why is it that every couple of years or so, the aftmost, bottom baffle attach screw on the #3 cylinder decides to part company with the engine? Doesn't seem to matter if there's a lockwasher or blue loctite holding that f***er on, eventually, it works its way out.

This time, found it on the ground underneath the nosegear fairing right after shutdown. Grrrrrr....

:)
 
Nord Lock

Sounds like a great candidate to test the holding power of the Nord Lock?

There are claims that it is as good as safety wire, reads like you have a spot to test that out.
 
I may try the Nord Lock when it comes out again in a couple of years :).

I just can't figure out *why* it's this one and only this one that does it.
 
Air flow buffeting, baffles rubbing cowling, coefficient of expansion. I always safety wire those on the airplanes that use that screw with a barrel nut or into the cylinder. Then they are there next year.
 
Thanks for the heads up. I’ll do a preemptive strike and order a couple of drilled screws from ACS next time I need something and I’ll have on hand when I start working on the baffles.

Is this the correct one? AN500A-416-12
 
Last edited:
Did it have a star washer and torqued?

I found two missing screws holding the baffle that takes oil cooler loads. I found that there is a plateau in torque with the star washer that is short of the Lycoming recommended torque.
 
Did it have a star washer and torqued?

Yes, and sort of (since it's a screw, not a bolt, tightened to same feel as the other 7 or so screws holding the baffles on...German torque). And blue loctite. Still came out.

Anyone using Nord-locks on these? I like the design, looks like a solution, just wondering what the real-world experience with Nord-locks here or anywhere else is...
 
Yes, and sort of (since it's a screw, not a bolt, tightened to same feel as the other 7 or so screws holding the baffles on...German torque). And blue loctite. Still came out.

Anyone using Nord-locks on these? I like the design, looks like a solution, just wondering what the real-world experience with Nord-locks here or anywhere else is...

Just torque them with new star washers. Gut en tite is about 30% too low. If it does not work then do something fancy. And don't use loctite. It is unnecessary.
 
Back
Top