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Rb25 Stock Bore?


zac320
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Hey guys I have 100000k stock block. Bent rods(hydrolock) I have found a really good deal on rb26 forged rods and cp pistons. They are stock 86mm size. Whats the possibility of the bore still being good? I've found a cheap rb26 crank to go with the rods and pistons aswell

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If the bores are fine then yes, normally you can just hone them and put standard sized (86mm) pistons in. You know 26 pistons will usually give you a lower compression ratio than standard 25 right?

It sounds like your best option could be simply sourcing a good complete stocker bottom end and throwing your head on it. Assuming you don't need a built motor?

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I thought if I go 26 crank aswell it won't?

Dnt need a built motor but it's either the forged rods and pistons or re ring the pistons that r in it and new bearings. I know it will be cheaper to get a new motor but I'd like to learn how to do all this

Edited by zac320
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Hey guys the local mechanic has convinced me to just put a new motor in. So I'm chasing a rb25 bottom end. No need for head or any other accessories. Just block to sump. It needs to be in good condition.

Cheaper the better especially if ur out of Vic as I'll have to freight it

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I have the bottom end here and I'm struggling to source a bottom end for cheap so. I'm thinking acid dip and hone block and clean up pistons and basic rebuild.

Bearings mains and rod $200

OEM rings $190

Nissan gasket kit $200

Rb26 rods $75 ( second hand from friend)

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I am going to do it. Took it to the Best local engine builder around and he doesn't want to do half the things, eg install rings on pistons but I install pistons. As he doesn't want to be liable if anything f**ks up. But he said I can take me engine into his workshop and do it there and ask for his advice which will be a great learning experience for me.

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im in your exact shoes.

it was option 1: buy 2nd hand unknown condition motor from someone.

or what i chose, option 2: rebuild, refresh and toughen up ("toughen up" being used lightly) my existing motor (ACL bearings, ross tuff harmonic balancer, crank oil drive thingo, ARP headstuds etc etc).

i think i would be kicking myself if i started getting huge blow-by after 12 months of getting a 2nd hand motor.

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