Technical 65mm pistons for an 817?

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Technical 65mm pistons for an 817?

MnMs 850 Spider

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Ok, very new here! Have had a 1968 850 Spider sitting in the garage for over 25 years now. And after 4 kids and a lifetime of stuff to do it's time to get to this one. I need to clean up the dash wiring from the previous owner, a new dash pad and rebuild the engine and it will be a beaut. My issue with the 817cc motor, it was bored .6mm over and now will need to go to 65mm. I can't find any references for pistons for the 817. Does anyone know if the 65mm pistons from the 843 will work in the 817? Or do I need to sleeve it and start over? I would like to keep the 817 in it. Any help would be appreciated. Thanks
 
Hi MNMS.

the 817 was under bored to reduce it below 50cu to stop the car needing smog restrictions.

It uses the same block as the 843cc block so std 65mm bore pistons will be good to use.

Are you sure it needs new pistons and not just a light hone and new rings.

Tim
 
Thanks for the reply. The engine had been bored. 8mm over and they put .6mm pistons and rings in! When I pulled it apart, half the rings were broken and the shop said it would be best to bore it. It had to have run that way for a while before I got it.
 
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