Author Topic: 2 3/4 HP TS Engine - Gudgeon Copper Caps  (Read 372 times)

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Offline Jim47

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2 3/4 HP TS Engine - Gudgeon Copper Caps
« on: 19 Nov 2020 at 01:44 »
I'm rebuilding a TS engine as part of a restoration.  The original pistons have gudgeon copper caps, apparently to centre the gudgeon pin and prevent the gudgeon scoring the bore. I have new (alloy rather than CI) replacement pistons similar to the originals (no provision for circlips to locate the gudgeon).  What do the original gudgeon copper caps look like and how are they best fitted?  I can turn them to size from copper round bar. My initial thought was to turn up caps like that used on the 350 EW - a shouldered cap, part of which is pushed into the bore of the gudgeon.  Advice would be greatly appreciated.  Thank you, Jim47.

Offline Keith

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Re: 2 3/4 HP TS Engine - Gudgeon Copper Caps
« Reply #1 on: 19 Nov 2020 at 08:57 »
I went through the process earlier this year for my CW. I made my end caps from PB2 (but normal bronze is probably fine).
Here is the link to the posts:

Cheers, Keith...

https://www.douglasmotorcycles.net/index.php?topic=7792

Offline Jim47

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Re: 2 3/4 HP TS Engine - Gudgeon Copper Caps
« Reply #2 on: 19 Nov 2020 at 23:56 »
Hi Keith
Thank you for your quick response and the extremely helpful information on the link, all greatly appreciated.
I will follow the good advice provide by you and others on the link and will go with bronze.  Interesting that in the Douglas spare parts list for 2 3/4 HP motors 1912 to 1921 copper gudgeon caps are mentioned, hence my mentioning them as I had no other source of information at the time.  Thanks again and cheers, Jim47.