safety wire on exhaust manifold bolts?

[beeryboats]

Why on earth does LEAF not sell drilled head cap screws to be able to safety wire the exhaust manifold bolts? I used to have a 1969 Chevy with headers that I ended up using drilled head cap screws and safety wire to keep them tight. This seems like a no brainer for an aircraft.

[Av8r_Sed]

I don't know about LEAF. Mine aren't safety wired. They do have a lock washer and have never loosened between condition inspections.

[Floog]

I too have a Chevy pickup with 'ram horn' exhaust manifolds which are notorious for expanding and contracting across the length (4 exhaust ports per casting!) causing the outer bolts to loosen over time. I like your fix!

However, Rotax headers don't move like that (one pipe per exhaust port) and I think the lock nuts (Lock Nut M8-WS12 / Torque: 12 Nm / 110 in. lb.) work fine in this application. Have you ever seen them come loose? I've even used them more than twice and still have not seen them loosen.

(can you tell) I'm bored in the desert....:)

[beeryboats]

I too have a Chevy pickup with 'ram horn' exhaust manifolds which are notorious for expanding and contracting across the length (4 exhaust ports per casting!) causing the outer bolts to loosen over time. I like your fix!

However, Rotax headers don't move like that (one pipe per exhaust port) and I think the lock nuts (Lock Nut M8-WS12 / Torque: 12 Nm / 110 in. lb.) work fine in this application. Have you ever seen them come loose? I've even used them more than twice and still have not seen them loosen.

(can you tell) I'm bored in the desert....:)

Yeah, the Camaro was always blowing exhaust gaskets until I doubled them up and wired the cap screws. The Kitfox is a restoration after 10 years of setting. It is built so far from a certified aircraft that I am second guessing everything I see. Not sure if what the builder did was right or not. I had to rebuild the entire fuel system except for the wing tanks. And I should have done them too.

[Av8r3400]

If you put two 100 pound cast iron manifolds on your Kitfox, you should definitely safety wire them.

If you stick with the Rotax parts, they are fine with the OEM lock washers and will never loosen.

[n85ae]

I drilled and safety wired mine on my IO-240B after I found one loosened
during annual. They should be, I would think.

Jeff