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so ive found my motors been rebuilt.

well ive bought my vr4 a few months back. and every time i dig into it. i find more stuff done to it. after knowing the car has a moroso oil pan ive been wondering if the motor was infact built. well tonight at work it was slow so i pulled in my car and pulled the plus. i put my borescope down and i find that it infact has been rebuilt... the pistons are aluminum.. but not forged. however. i saw the stamp that the pistons are over size 0.50 this has me excited to know that the motor does not have the 175k on the bottom end that the chassis does. however i am worried that with a .50 bore how much more can i go when i decided to build the bottom end with a forged setup. on its current state i will be boosting it to 25psi. as i know it will take it (my laser rand 30psi for 20k miles) anyhow. to really see if the rods are stock is for me to drop the oil pan with a seeping gasket i have a reason to. but im not looking forward to it. however. my question stays... how much furter can the block be bored if its already at .50? and what is the displacement now that its punched 5 mm's out?

You're only .5 mm overbored, which translates to a .020" overbore, and most aftermarket companies offer a 1mm/.040" piston.

Terry Posten

Well-known member
Dec 16, 2003
Davenport, Iowa USA
I'm running 40 over JE slugs on an o-ringed stroker setup, and it will be fine for 35psi+.

You have no worries.


Well-known member
May 4, 2003
Clarksville TN
Drain the oil and scope to see the rods, just because the pistons are good doesn't mean the rods are. You may get lucky and find Manley or x beams but may just be stock 6 bolt rods. As we know there are cheap owners everywhere and half ass garages that will say they do something when they don't. Yea we put in arias pistons and x beam rods to find eagle wiesco's years down the road.

thanks guys. i didnt even think to drain the oil and borescope thru the drain bolt. ill wait a few miles. the oils new and i use mobil 1. its not exactly cheap /ubbthreads/images/graemlins/frown.gif


Well-known member
Sep 16, 2001
dirty jersey
good thing they used aluminum pistons
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