Jump to content
SAU Community

Recommended Posts

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

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/
Share on other sites

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?

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6550348
Share on other sites

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
Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6550524
Share on other sites

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

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6553856
Share on other sites

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)

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6554057
Share on other sites

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.

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6554109
Share on other sites

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.

Link to comment
https://www.sau.com.au/forums/topic/410108-rb25-stock-bore/#findComment-6555672
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Yep, pretty much what you said is a good summary. The aftermarket thing just attached to the rim, then has two lines out to valve stems, one to inner wheel, one to outer wheel. Some of the systems even start to air up as you head towards highway speed. IE, you're in the logging tracks, then as speeds increase it knows you're on tarmac and airs up so the driver doesn't even have to remember. I bet the ones that need driver intervention to air up end up seeing a lot more tyre wear from "forest pressures" in use on the highway!
    • Yes, but you need to do these type certifications for tuning parts. That is the absurd part here. Meaning tuning parts are very costly (generally speaking) as well as the technical test documentation for say a turbo swap with more power. It just makes modifying everything crazy expensive and complicated. That bracket has been lost in translation many years ago I assume, it was not there.
    • Hahaha, yeah.... not what you'd call a tamper-proof design.... but yes, with the truck setup, the lines are always connected, but typically they sit just inside the plane of the rear metal mudguards, so if you clear the guards you clear the lines as well. Not rogue 4WD tracks with tree branches and bushes everywhere, ready to hook-up an air hose. You can do it externally like a mod, but dedicated setups air-pressurize the undriven hubs, and on driven axles you can do the same thing, or pressurize the axles (lots of designs out there for this idea)... https://www.trtaustralia.com.au/traction-air-cti-system/  for example.... ..the trouble I've got here... wrt the bimmer ad... is the last bit...they don't want to show it spinning, do they.... give all the illusion that things are moving...but no...and what the hell tyre profile is that?...25??? ...far kernel, rims would be dead inside 10klms on most roads around here.... 😃
    • You're just describing how type certification works. Personally I would be shocked to discover that catalytic converter is not in the stock mounting position. Is there a bracket on the transfer case holding the catalytic converter and front pipe together? If so, it should be in stock position. 
    • You talking about the ones in the photo above? I guess that could make sense. Fixed (but flexible) line from the point up above down to the hubcap thingo, with a rotating air seal thingo. Then fixed (but also still likely flexible) line from the "other side" of the transfer in the hub cap thingo up to the valve stem on the rim. A horrible cludge, but something that could be done. I'd bet on the Unimog version being fed through from the back, as part of the axle assembly, without the need for the vulnerable lines out to the sides. It's amazing what you can do when you have an idea that is not quite impossible. Nearly impossible, but not quite.
×
×
  • Create New...