Rb30-gtr Pistons

[R30_elliott]

Hi guys, long time reader here first time poster

I've got a r32 gts25 sedan that i've sold my 20det setup (284rwhp if anyone cares) to build a RB30det, so far i've got a garret truck turbo, similar size to 3540, rb30e bottom end and r32 25de head, gtr valve springs, oil pump collar, just buying up the bits as i see them basically

I've also aquired a set of 26dett pistons, I've tried searching and haven't found a definite answer to if i can use them or how much work is required? i have a set of 30e pistons to which i'll use if the 26's arent any good, basically what i'm asking is  a) how hard are the 26 pistons to fit, and b) is it worth it?

thanks in advance guys. I'm sure i'll have many more questions as the build progresses

Cheers

[bubba]

Pretty sure you have to use RB30 pistons as their pin heights etc are to suit RB30 rods & crank..

[R30_elliott]

Pretty sure you have to use RB30 pistons as their pin heights etc are to suit RB30 rods & crank..

cheers for the reply, so i cant use 30 rods with 26 pistons? i havent had a chance to measure anything up yet, was trying to avoid wasting my time if people already knew the answers haha

might have to take them into work and whip up some drawings to see if its a suitable option,

[bubba]

Not sure on the exact differences, I'm using RB30 spec forged pistons. You might find that with 26 pistons on 30 rods on a 30 crank that you could be smashing pistons into valves.. need an experienced RB builder to answer that

[handyandy28]

i do not belive that the 26 pistons will work either

[drive2slide]

i'm pretty sure 26 pistons don't fit man. RB25 pistons fit though

[darksyde]

they do fit, heard of it done over here in nz. check the rb30 guide. block needs to be decked as they come up short compared to the rb30 pistons

[R30_elliott]

cheers guys, turns out one of them is poked anyway so ill prob just stick with the 30 pistons, on the subject of 30 pistons, i've got a set that i had ultrasonically cleaned, when they came back they had lots of pitting in the top of the piston, im assuming its just bad casting/ has anyone else had a set that were the same? i tried to take a pic but it wont pick up the detail- aka budget camera

[bubba]

That pitting is probably from detonation..

[R30_elliott]

That pitting is probably from detonation..

I was hoping that wasn't the case but had my suspicions, picking up another motor tomorrow hopefully the pistons in that one are better, first motor had a bent crank (god knows how) so i had to buy a whole new motor to get a new crank, what a mission just to get more power!

[bubba]

Bent cranks are quite common in i6 engines.. just make sure you get all your clearances checked and machine appropriately.

[R30_elliott]

Bent cranks are quite common in i6 engines.. just make sure you get all your clearances checked and machine appropriately.

 

it had about 0.3 bend in it, decided to try another as its cheaper to get a new one than grind, bit of a gamble to but its a low k's engine so should be ok

[bubba]

I learnt the lesson of not grinding and slapping it together with standard bearings.. destroyed an oil pump and nearly my block.