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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
Originally Posted by DSPTurtle View Post
Nice work. I'm curious though, did you balance big and small end or just overall weight? Should spin smooth as a baby's bottom!
Thanks! I tried setting up a funky end for end balancing rig but I couldn't get any consistancy with how I was trying to do it so I ditched that set up and just balanced them overall to the exact same weight on my triple beam scale.
They were all within 2 grams of each other to start with so I didn't remove a lot. Most of what I removed was from the squared off edges where the rod and cap come together. You can see that area is shiny and rounded off now. I used a 6" DA made for doing body work. I locked down the 6" pad so it spun like a grinder and I used sticky back 320 grit sandpaper spinning around 15,000 rpm to do this.
In the past I've done entire rods in my old BMW's and polished them to a mirror finish and spent many hours doing it but I didn't want to do all that to these. I guess I did them in around 4 hours.
A week ago I had the best automotive machine shop in town resize the big ends, they were out of round and they installed my new wrist pin bushings and honed them to fit my new wristpins for the right oil clearance.

Here's my funky end for end rig on top of my refrigerator I tried first that didn't work. Too much friction and inconsistant. Maybe hanging one end of the rod from string would work but I decided to just weigh them overall and that would be good enough for my street car.

This is how I positioned them on the scale to weigh them overall. Kevin Jeanette gave me the picture on the wall in the background back when I worked for him at Gunnar Porsche in the mid eightee's

Here's the new pistons and wrist pin assemblies that all weigh the same now after i removed material from the ends of the wristpins. I didn't do anything to the new pistons. The new cylinders are in the box.

Old 03-12-2014, 04:49 PM
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