How to R&R press fit pistons and balace rods 6bolt 1g 4G63

[BogusSVO]

How to R&R pistons and Balance Rods

1G 6 Bolt 4G63T

The used rods and pistons, the pistons are being replaced due to cracked and broken ring lands.

I start off by marking the front of the rod with a center punch

Next is to find the proper sized press pieces to press out the wrist pins.

Due to the pressures used to press out the wrist pin, care must be used, the piston itself can bust sending pieces of it flying that can and will cause injury.

After the pistons have been pressed off, and the small end inspected for scoring, the rods need to be numbered on both the rod and end cap.

Now the rod and caps can be split and cleaned, I use a glass beader to remove all the grime

Once that is done I spray them down with a good brake cleaner and blow them dry

Chase the rod bolt threads with a nut to remove any dust left from the glass beading.

Now to match the rods back with the caps

Install the rod nuts.

Now the rods are clean and assembled, they can be balanced. Start off by weighing all the small ends

The weight will be matched to the lightest one.

Once the small ends are matched, weigh the overall weight of each rod, and match the overall weight by removing material from the bottom of the rod.

Now that is done, it is time to match the weights of the pistons WITH OUT the wrist pin installed.

Then weight match the wrist pins.

Now that all the weights are with in 1/10 a gram the pistons can be hung back on the connecting rods. The small ends must be heated so the wrist pin can slip through it.

This must be done very quickly so the wrist pin is fully in place before the small end of the rod contracts around the wrist pin holding it in place.

[Goat Blower]

Good info, I'm tempted to do this myself next week. Would it be worth it to bake the old pistons and rods in an oven to get the pins out instead of pressing them cold?

[BogusSVO]

I doubt it.. an oven will not get them hot enough to expand the small end of the rod...

to press fit the wrist pin, the small end is heated to about 1200* F

[Goat Blower]

Gotcha, looks like I'll go get it done unless somebody's got a cheap rod heater laying around. :-)

[tpunx99GSX]

Why would someone need to do this? If you have aftermarket pistons and rods does this need to happen? My wrist pins slipped out and in nicely without the need for pressure.

[BogusSVO]

if you have aftermarket rods and pistons, most the time they are a full floating set.

but the carmakers use ths set up beacuse its quick and cheap

his would hav to be done if you ran OE style piston on a factory rod.

[Andrew7dg]

I love these "How To" that you keep posting up!

This doesn't need to happen if you have aftermarket rods and pistons. They are held in there differently then stock mitsubishi stuff.

Even if I am not going to be doing this because I don't have the tools, I like just knowing what a machine shop does (or should be doing)

[BogusSVO]

Glad you do!!

Thats why I do post them, so people can learn.

Alot of shops do not update there equipment, due to the cost of it. so what worked on a 70's smal block will not work on a 4g63 or alum head, mainly surfacing.

I did post oe on full floatong pistons.

http://www.mitsustyle.com/forums/showthread.php?t=26104