match weighing pistons

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radish
Posts: 16
Joined: Thu Mar 04, 2010 2:18 am

match weighing pistons

Post by radish »

HI

I have just weighed my pistons and the difference is 0.3g. I have also matched the pins, clips and rings and as a complete unit i can get them all within 0.4g.
it is the 1 of the pins that is where the difference is 1.5g, Is it advisable to remove material from the ID of the pin?

Cheers
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Piledriver
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Joined: Sat Feb 16, 2002 12:01 am

Re: match weighing pistons

Post by Piledriver »

Yes.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
radish
Posts: 16
Joined: Thu Mar 04, 2010 2:18 am

Re: match weighing pistons

Post by radish »

Thanks very much.
Ol'fogasaurus
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Re: match weighing pistons

Post by Ol'fogasaurus »

I think "where is also in the picture too. In the wrong place you could have problems. I remember hearing this being a problem years ago and I think things haven't changed that much.
radish
Posts: 16
Joined: Thu Mar 04, 2010 2:18 am

Re: match weighing pistons

Post by radish »

Ol'fogasaurus wrote:I think "where is also in the picture too. In the wrong place you could have problems. I remember hearing this being a problem years ago and I think things haven't changed that much.
I would of thought through the hole at each end so it's equal?
I am confused that the total mass I can get equal but would still need to do the pin.
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Piledriver
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Re: match weighing pistons

Post by Piledriver »

Sometimes there is a bit of flash in the middle you can smooth out, but the weight needs to come off the ends.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
Ol'fogasaurus
Posts: 17757
Joined: Mon Nov 13, 2006 10:17 pm

Re: match weighing pistons

Post by Ol'fogasaurus »

Thank you Pile. I still have my "think about it" habit from being a "checker/mentor" of others work for over 30 years. I point out something and if they find the answer themselves they are more apt to remember it than if I give them the answer. Sorry!
Ol'fogasaurus
Posts: 17757
Joined: Mon Nov 13, 2006 10:17 pm

Re: match weighing pistons

Post by Ol'fogasaurus »

I did a quick search on balancing and got a great answer from Eaton:

http://www.eatonbalancing.com/blog/2007 ... ng-part-3/

Here are some more I found. There is a lot of info, including videos, depending on how you word the search:

http://aircooledtech.com/balancing/

viewtopic.php?t=124244

http://aircooledtech.com/balancing/

http://www.shoptalkforums.com/viewtopic.php?t=42324

Also remember that taking weight from the wrong place can weaken the piston catastrophically.
radish
Posts: 16
Joined: Thu Mar 04, 2010 2:18 am

Re: match weighing pistons

Post by radish »

Thanks, that info at Eaton is great.
radish
Posts: 16
Joined: Thu Mar 04, 2010 2:18 am

Re: match weighing pistons

Post by radish »

Crisis over, I re weighed on 2 different scales today and the original weights were incorrect! Now I'm lucky enough to have access to a laboratory with plenty of weighing equipment not £15 kitchen scales but these cost between £700-2500. So all good now.
Thanks for your help.
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