The Top Mitsubishi Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

Connecting Rod question

GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Hi engine gurus! I'm new to 4G63 engine and wonder when replacing pistons could rods be re-used if I'm using new pins? There is no pin locking ring on either side of the piston. I'm assuming they were press pushed in parts cold/warm state

Thanks
A
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
Yep, it's a press fit pin. Rods can be re-used as long as the are checked out. Need to be sure the large and small end are not out of round or have taper.
 

GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
Thanks Ryan! So, please correct me if I'm wrong here: All I need to do then is to press the pins out, inspect the rods, if ok, cool them down, cool the new pins also and press them in. Correct? Any special things I have to be aware of? All parts are stock.

A
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
Never done it myself, but I would imagine you don't wanna cool the rods when reinstalling. Just the pins. Are you replacing the piston with stock?
 

CutlassJim

Well-known member
Joined
Jul 17, 2006
Messages
1,698
Location
Manchester, NH
You would chill the pin and heat the small end of the rod. Stock pistons are fine to reuse too unless you're changing to a higher compression ratio. The stock pistons are just as strong as anything aftermarket until you get into big money stuff.
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
EVO pistons make for great upgrades. Requires a larger pin and machining of the small end of the rod. You get a whole 1 point increase in compression.

2g pistons are good for 8.5:1 compression, EVO goes to 8.8:1.
 

GTX

Well-known member
Joined
Apr 13, 2012
Messages
100
Location
Toronto, Canada
My cylinders are in a decent shape, but pistons have a bit of wear. Since the engine is out I will replace the questionable parts.
Only need about 300HP. Replacing pistons with stock. From what I read, Big16g should not destroy them if stay under prescribed pressure.
 

362Ryan

Well-known member
Joined
Aug 9, 2013
Messages
116
Location
Alaska
I would still get a set of evo pistons. The bump in cr will wake the engine up on the street.
Also consider a 2g head. Running both of those would give you quicker spool up than a stock setup on a 14b.
 

mitsuturbo

Well-known member
Joined
Jun 2, 2008
Messages
3,544
Location
Near Seattle, Washington
Depending on the machine shop, sometimes it's not worth it to have the stock rod reconditioned, then have the small end narrowed and the hole enlarged, due to cost. Considering you can buy eagle rods for 325ish brand new with whatever size pin end you like, I could see why someone would opt for stock pistons.
 

fuel

Well-known member
Joined
Feb 23, 2009
Messages
2,165
Location
Toronto, ON, Canada
Yeah if the stock rods need any kind of work (ie boring out small end for 2G/Evo wrist pins, or reconditioning of any kind) then I would just drop the money on new aftermarket rods and go for higher CR pistons for better low rpm response. The previous owner of my car rebuilt the engine with stock (brand new from memory) 7.8:1 pistons and I wish he had gone for the Evo pistons instead.
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
When I built my engine I estimated the cost to recon the rods at about 200 with machine work, cleaning, and installing ARP rod bolts. I ended up buying some eagle rods for 280 shipped. An extra 80 for balanced, stronger, and lighter rods was well worth it.
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned

Recent Forum Posts

Top