170 crankcase bushing groove

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andrew
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170 crankcase bushing groove

Post by andrew »

Noticed this groove in the top crank bushing of a 170. It is about 1/4 mm deep, spiraling from bottom to top of the bushing. Photos hard to get but tried a few angles.

It looks uniformly deep and is cut sharply into the bronze, as if machined on purpose. But I’ve not seen this before on the regular seagulls.

Is this just damaged or did they come with this groove perhaps for lubrication? This housing came from a damaged motor (see 170 Postmortem thread) so possible the groove was carved at same time the big end failed.

Thanks

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Horsley-Anarak
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Re: 170 crankcase bushing groove

Post by Horsley-Anarak »

That is normal, just for lubrication.
andrew
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Posts: 171
Joined: Wed May 24, 2017 5:37 pm
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Re: 170 crankcase bushing groove

Post by andrew »

Thanks for confirming. Glad to hear it’s not ruined, at least by the groove. Still need to check out the case, there are a couple minor nicks (visible in the photos) presumably from when the big end failed and bits were rattling around in there.

I haven’t noticed a groove like this before, did they also have them on the 40s/centuries etc?
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