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


BogusSVO
03-30-2010, 04:05 PM
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.

http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4241.jpg

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

http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4242.jpg

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

http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4246.jpg

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.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4245.jpg

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.

http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4253.jpg

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

http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4255.jpg

Once that is done I spray them down with a good brake cleaner and blow them dry
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4257.jpg

Chase the rod bolt threads with a nut to remove any dust left from the glass beading.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4258.jpg
Now to match the rods back with the caps
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4256.jpg

Install the rod nuts.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4259.jpg

Now the rods are clean and assembled, they can be balanced. Start off by weighing all the small ends
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4260.jpg
The weight will be matched to the lightest one.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4262.jpg
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.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4261.jpg
Now that is done, it is time to match the weights of the pistons WITH OUT the wrist pin installed.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4264.jpg
Then weight match the wrist pins.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4265.jpg
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.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4263.jpg
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.
http://i261.photobucket.com/albums/ii49/BogusSVO/4G63T%20rods%20pistons/DSCF4266.jpg

Goat Blower
03-31-2010, 11:56 PM
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
04-01-2010, 09:44 AM
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
04-01-2010, 10:29 AM
Gotcha, looks like I'll go get it done unless somebody's got a cheap rod heater laying around. :-)

tpunx99GSX
04-02-2010, 01:39 PM
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
04-02-2010, 02:56 PM
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
04-02-2010, 04:12 PM
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
04-02-2010, 04:30 PM
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