Engine mount grounding strap & spacer?

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8313
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Engine mount grounding strap & spacer?

Post by 8313 »

Hello all,
We are changing out the worn engine mounts (conical style) does anyone know a source for the metal spacers and grounding straps?
The metal spacers that hold the conical mounts in have the following dimensions:
ID .380”
OD .440”
Wall .032”
Length 1.90”

We have two grounding straps that are cracked. Has anyone found a source for these?

Thanks for the help
2356
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Re: Engine mount grounding strap & spacer?

Post by 2356 »

I used a flat braided strap like a battery ground. I went from an engine stud to the mount.
5469
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Re: Engine mount grounding strap & spacer?

Post by 5469 »

Hello,

I will inspect the grounding of my C85 12F soon,
It would help me if you please post a photo when you finish your grounding ?

Thanks a lot,
Regards,
Horacio Berardone Bouhébent
LV-NGL 1946 C140 SN 10.260.
Based CLN, Colón, Entre Rios, Argentina.
Formerly 9Q-CKN Based FZAB, NDolo, Kinshasa, Congo.
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6643
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Re: Engine mount grounding strap & spacer?

Post by 6643 »

It's pretty simple. There is a strap, one end attaches to the bolt opposite the one that holds the oil fill tube to the engine case (same spot on the opposite side of the engine) and the other end goes between the head of the engine mount bolt and the engine mount itself at the lower left mount point.
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Re: Engine mount grounding strap & spacer?

Post by 6898 »

I've tried to find those spacers there just not available. I've also been told the newer mounts have a smaller ID. and the spacers are not needed? the last set of mounts we installed we did not use spacers but its hard to get the proper torque without them thinking that the washers bottom out on the spacers to give you that number? Keep me informed if you find out different.
Jeff T 1948 C-140 NC3600V
Past President 120 140 Assoc. 2019-2023
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6643
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Re: Engine mount grounding strap & spacer?

Post by 6643 »

The Continental overhaul manual Figure 14 shows the mount, without the spacers. I've never found any evidence, but it makes sense that the ID of the rubber mounts was once larger. The spacers DO NOT FIT in the current mounts. They had worn through the rubber parts on my plane back in about 1990, so I removed them. IIRC, they're made from off the shelf chrome-moly tubing. Also, IIRC, the bolts called for in the parts catalog were too long once the spacers were removed.
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