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Discussion Starter #1
Pull your balls to properly clean your crank


I know this topic has been talked about some.
Some say it not needed, but I disagree.
The crank for a 4g63 is of the cross drilled design.

This means that there is an oil galley through both the main and the rod journal with an intersecting oil galley that joins the main to the rod. Due to the way the oil galleys are drilled, from the side of the rod throw to the main journal oil galley, the factory installs a press fit ball.



Now a segment of the intersecting galley is “dead space” this segment is from the cross drilled oil galley in the rod journal to the outside of the rod throw.
The common way to remove the ball is to heat it with a tig welder to loosen it, then weld a pull point on the ball and fight it out.

Once the ball is out, you will see the hard packed crud that builds up in the dead space.


Once you have the crud exposed, use a drill bit slightly smaller than the oil galley and drill the crud out, then a small copper brush and compressed air to get the rest out.
You will have 4 piles of crud.


A closer look of the crud from one galley.


So you can have an idea just how much crud is built up in the crank.


I believe that the solvent tanks and spray cabinets that a machine shop uses, also the cans of brake clean the DIY use, breaks down the bond that holds this crud in place and softens it so in a rebuild it gets washed when the engine is primed with oil on the stand, then the new break in oil picks up a small amount of the loosened crud and washes it into the new rod bearings.
 

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Discussion Starter #5
Where do you get new balls to install? Or what size? Whats the best way to install them an ensure a tight fit and proper seal? Very interesting to see the comparison with the dime.
I tap and use set screws for plugs, Ill be doing a write up on that shortly.

Some people tap them and thread a plug in to them, some weld them shut.
I never even thought about doing this! Great information!
It need to be done on any build, When I first joined another DSM fourm, I read thread after thread about new builds spinning rods in 50 miles or less, I knew there could not be that many bad assemblies. So after looking at some spun cranks. This is what I found.
 

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I tap and use set screws for plugs, Ill be doing a write up on that shortly.
Sounds good. I'd be interested to see that and if you use any thread locker or sealer with them? I've been lucky not to have any issues with the couple built up engines I've run, but love this kinda info for the future.
 

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My preferred way to block the hole off afterward is to tap it, thread in a setscrew with loctite metal bonding compound, stake it in a few places to hold it, and throw a quick tack weld on it. It may sound like overkill but if anything should happen that allows that setscrew to come out, it's a very bad day.
 

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Do any of these methods affect crank balance? Adding new weight (welds) or taps and set screws, will that throw off the balance?
 

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Not enough to worry about with a stock rod build. But most balance a H-beam rod/forged piston combo spin balanced anyway.

The 4 press fit balls weigh the same, and the set screws will weigh the same, so it keeps it close to the factory balance.

Personally, I would say the crud would throw the balance off more, since the factory did not take that into account, and it does not build up equally.
 

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excellent idea,
i work on natural gas Caterpillar engines and we do the same thing. they have very hard bearings sensitive to any contamination so we must clean the dead space completely
 
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