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Old 10-22-2013, 02:09 PM
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Stretch Stretch is offline a shield of steel
Join Date: Sep 2009
Location: Somewhere in the Netherlands
Posts: 14,461
Originally Posted by 1project2many View Post
For future repairs, and / or to allow the balancing operation to progress when all parts are not available. If pistons are balanced to each other and rods are balanced to common weight, then a replacement piston can be installed without re-balancing the the rod/piston assy.

An additional reason to maintain consistent piston weight (and to match the original weight) is to maintain the crankshaft counterweight or "bob weight" effectiveness. The crank essentially unbalanced to counter the force applied as the pistons peak at TDC. Changing piston weight changes the magnitude of force being applied to the crank.

You can (and I do) "home balance" rods by using a fixture that allows fastening two rods to a common pin and allowing the pin to roll on a level surface. The heaviest rod always falls. The greatest challenge was making the fixture consistent when balancing the small end. Turns out it produces better results than the chain fixture above.
That is very clever - simple and clever

1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior

Don't leave that there - I'll take it to bits!
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