Lightened Gudgeon Pin



FurryOnTheInside

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Joined
Sep 23, 2013
Messages
3,292
I’ll get a postage price if your interested? Give me some time and I’m going to see what I can take from the piston as well
View attachment 81548
Very interested! It's one of the very few things that can't be done on my coffee table using small/cheap tools.

I was able to remove only 1.5 grams from inside the piston (non windowed) so I resorted to grinding a little off the con rod (for an unknown weight reduction) to reduce the reciprocating mass. This was enough, along with the 3/8" holes in the crank cheeks, to get perfectly reasonable balance up to around 7000rpm, but it is a little bit shakey above that speed. (That might be the timing as much as the balance though. I have a stock CDI with 1.2mm offset magnet key.)

You can add three of these beauties to the parcel with my two Jaguar designed CDIs! ;) ;)
 
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HeadSmess

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Joined
May 17, 2010
Messages
3,006
oh i does like a nice carbide drill... though they arent quite as impressive as watching a T-drill take out a 50mm hole at 100mm deep in a matter of seconds.

idea with the piston...looks like theres at least a bit of meat around the bosses so you could run an endmill through, putting two flats on the side of the piston.... though looking at the clip grooves...maybe not. (on a 48 at least)

make a split bush clamp so you can ensure concentricity, and you can bore out the back of the skirt a bit, until you meet the bosses (wife...shes a stunner!)
 

jaguar

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Nov 25, 2010
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3,453
You should sell them. Most everyone with a china girl engine has too much vibration. This will lessen the vibration.
 

Stoneman

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May 20, 2017
Messages
691
You should sell them. Most everyone with a china girl engine has too much vibration. This will lessen the vibration.
I have been, I’ve just got to work out the drill bits.
I’m talking to the tool sharpener about it as the edges dull real quick, I’ve just hooked up a mister for cooling so I’m hoping the bits will last longer.
The carbide bits here are quite expensive.
 

jaguar

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Nov 25, 2010
Messages
3,453
Let us know the cost (including shipping) and how to pay. I assume they come from Australia.
 

Stoneman

Active Member
Joined
May 20, 2017
Messages
691
I’m on my way to see him today with another 2 bits needing sharpening so I get get an idea what it’s actually costing me.

Will do though and yes from Australia. . It was all thanks to your web site :)
 
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