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DMD Diamond pistons

PostPosted: Sat Jun 26, 2021 2:09 pm
by Storkfoot
I have a Tv175 2 ring piston. I bought it quite cheaply on eBay. I wasn’t planning on using it as I also bought what I thought was a NOS Borgo piston (turns out it must be a 175 Conversion piston).

Anyway, the DMD piston has come in a plain box although it is stamped DMD on the head of the piston.
An internet search leads me to believe that they are a Taiwanese company: ANQING DIAMOND(DMD) PISTON RING MANUFACTURING CO.,LTD.

Any thoughts or experiences as to whether I should use it on a standard motor?


Re: DMD Diamond pistons

PostPosted: Sat Jun 26, 2021 8:40 pm
by Storkfoot
Image

I see Scooter Restorations sell Diamond pistons which are Indian.

Does anyone know whether this is a Diamond piston?

Re: DMD Diamond pistons

PostPosted: Sun Jun 27, 2021 2:48 pm
by Knowledge
I would trust the quality of a Taiwanese posting and rings, especially in an engine in a relatively low state of tune like the TV 175. I think someone told me that Taiwanese rings are often OEM parts for manufacturers.

Has anyone heard anything different?

Re: DMD Diamond pistons

PostPosted: Sun Jun 27, 2021 3:35 pm
by Warkton Tornado No.1
The Taiwanese are reknowned for pistons (& rings) & include Mitaka.

The problem with replacement pistons for Lambrettas is that there is no longer a standard bearer such as Innocenti. So @ best you might get something that conforms to a standard suitable in the 1960's. That may be fine for a standard rebuild, but if pushing the boundaries, I will always select a piston intended for another market: Honda, Kawasaki, Polaris, Suzuki, Yamaha etc

That said, I put a GOL piston in an extensively reworked Indian alloy barrel & it went well. It looked well made & had nice rings, so better than expensive 'Lambretta specific' pistons designed by somebody whose only credentials are that they like taking money.

Re: DMD Diamond pistons

PostPosted: Sun Jun 27, 2021 5:26 pm
by Storkfoot
Thanks for the replies. I was quite comforted when I saw they may be Taiwanese, however, I have since see that Diamond are Indian, not that that is necessarily a bad thing.

The piston is 170g as opposed to the Borgo that was on the scooter which was 209g. But the ring pegs look a bit flimsy to me the more I look at the piston. I think I’ll keep it as an emergency replacement and get a Mahle or GOL, both of which I have used in the past.