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Upgrading To An Rb26 :d Have Some Tech Questions

ReganGTS25T

By ReganGTS25T,
in Engines & Forced Induction

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ReganGTS25T Enthusiast

ReganGTS25T

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i just sourced an r34 rb26 soo i will be selling/parting out my 607rwhp rb25 to upgrade to a big borgwarner turbo and 9k rpms big 280 cams single stage external oil pump etc etc but i have my tomei rods on my engine i know i can use but can i use my cp pistons from my rb25 on the 26?

blind_elk Grand Master

blind_elk

Posted
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Just looking at the ACL site, it shows that the RB25 / RB26 pistons are different in 2 areas:

Crown volume - RB26 = 16.3cc, RB25 = 11.5cc

Comp Height - RB26 = 30.3mm, RB25 = 31.3mm

I think the Comp Height difference means you will smash a RB25 piston into the head of a RB26, because the piston sits higher on the gudgeon pin / small end.

I would imagine most others are the same.

And RB265 / RB26 have different stroke, so you probably can't use the same rods either.

ReganGTS25T Enthusiast

ReganGTS25T

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Just looking at the ACL site, it shows that the RB25 / RB26 pistons are different in 2 areas:

Crown volume - RB26 = 16.3cc, RB25 = 11.5cc

Comp Height - RB26 = 30.3mm, RB25 = 31.3mm

I think the Comp Height difference means you will smash a RB25 piston into the head of a RB26, because the piston sits higher on the gudgeon pin / small end.

I would imagine most others are the same.

And RB265 / RB26 have different stroke, so you probably can't use the same rods either.

well your totally wrong about the rods they fit either engine, the rb26 has 2 more mm's of stroke but it has 1 mm less of compreson height, and the dome cc's compensate for the extra mm of stroke thats my theory ive talked to soem engine builders in the states and they told me ill be fine i entered all the calculations on my engine calculator shows 8.1 compresion just want to knwo if thiers something im missing or if thiers something that wont fit

2LV8ETR Mentor

2LV8ETR

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well your totally wrong about the rods they fit either engine

Why ask if you're going to research and find the answer yourself???

ive talked to soem engine builders in the states and they told me ill be fine

Big mistake.............Good luck! ;)

You cannot use the rb25 pistons in the 26, due to different deck height, comp height, gudgeon pin height.

I say we let him work it out himself as he's gotten some excellent advice................

ReganGTS25T Enthusiast

ReganGTS25T

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Why ask if you're going to research and find the answer yourself???

Big mistake.............Good luck! :(

I say we let him work it out himself as he's gotten some excellent advice................

we'll see, and if you look at my first post i never asked if my rods would fit i know my rods fit they are rb26 rods no brainer thier suposedly with a stock height head gasket and the 25 pistons i should be at 7.8 compresion and if you dont want to help me im prety sure thier are other people who know more then you on this forum :) to bad all my aussie freinds dont know crap about rb26's heh talkinga bout you antony 2rismo rezlo cjmark

2LV8ETR Mentor

2LV8ETR

Posted
Posted
oi.. Raegan is a cool dude. He has been through some bad shit more then most of us put together. Nothing wrong with Peru, i would go there.
log on msnger fool i want to talk to you
to bad all my aussie freinds dont know crap about rb26's heh
well your totally wrong about the rods they fit either engine

lol he's TOTALLY wrong? heh ur arrogant..

Yup, a good bloke.........

He may have been through some shit man, but it doesn't excuse talking to people like shit trying to help him.

He's getting advice, he should be thankful and not take what he's being given for granted, even if his mates in the US know everything.

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