joe blo

not strong enough? somethings gotta fail if they cant handle it. weakest part possibly? i dunno

yeah there mahle cast pistons

well i got it pulled down at shop. no signs of detonation. 4 broken ringlands. says it broke from too much boost (17.6 psi). pistons musnt be comparable to the genuine nissan ones like i was hoping

sorry thought i mentioned it was run in on dyno at the start. once i picked it up the first time i didnt let it sit idleing at all ever. i was abit concerned about if it would be run in even though he did it on the dyno so i treated it as if i was still running it in. only did about 140 kms. no extended idleing. not holding constant revs.

yeah i was thinking the bores were pretty shiny. i paid the tuner guy to run it in for me and he said it would be fine to drive around until i got it tuned again properly. only did about 150kms total before returning to the shop for final tune

what markings do you mean? the bits in the middle are from where i wiped it with my oily fingers. or the marks on the side of it? only just noticed them looking at the picture again. dunno about bent valves the scratch marks going up and down the bore appear in atleast 4 of the bores. maybe 5. cant remember.

the rear one had 90psi. will have to look again to confirm the other scrathed one im not sure. i cant remember the finish of them when i put them in. somethings telling me the finish wasnt real smooth to start with. so not sure. hopefully take it to shop tomorrow or next day to get the rest pulled down

ok guys. pulled it down abit. note the scratch marks at the top of one of the bores. thats number 6. also done it on number 2 or 3 i think. also both sides of the headgasket are shown. one of the pistons has like a dirty/rust coating on it or something. pretty weird

yeah. i could have tuned it to blow up myself and saved the money dunno whats happened yet. hopefully this week

nar not suitable for this one. thanks anyway

all the nissan ones do. the first vl ones didnt.

need one asap guys.

i meant the bottom compression ring (think its called that) not the oil control 3 piece one

i dont think thats a problem now. i checked on my old rb25 pistons rings to test there strength. the top ring is real strong and doesnt break and just bends. the bottom has the same strength as the one i broke. so i gather the bottom is made of different material to the top. it was a bottom i broke on the rb30 and its the same breaking strain pretty much. was replaced with the same brand and stuff pretty sure

yeah ok. will see how things go i guess. got so much car stuff to do lol. gotta put head on and clutch and put all back in car in sierra. water pump change in swift. now sort skyline out again. o well. just the way it goes i guess

if its from detonation thats its broken is it out of the question to ask for my tune money back atleast? or do i pretty much pay him to blow it up for me? cudda done it myself alot cheaper. tune was abit homo to say the least. backfiring (sometimes, about half the times) about 3900rpm (once it got about 10psi up) when getting into it and if it did it wouldnt really rev much higher. was doing it on the first boost cut tune thing and did it the 1 good "test" i did on my way home from dyno after the problem happened

hi guys. i wanna buy a rb30 motor series 2 if its out of a vl so its got the oil and water holes in it already. i hopefully wanna compression test it. only really want the bottomend so can give ya the head back or whatever if ya want. im on northside of brisbane but will travel abit to get one thanks mates

going by the compression test results is it time to pull the motor out? leakdown test not required now?

with the block bored 40 thou over and minimum use after it would i be able to put some other brand cast pistons in this motor to try again? different tuner. the guy wasnt real good at the wolf to start off with should i do leakdown test still or is the compression test enough to warrant pulling it apart? wanna go full forged motor but id blow so much on it if i did. coz id get this and that and then i might aswell get that and that also sorta thing

maybe the mahle cast pistons arent as strong as the nissan ones?

no. in brisbane

yep. oh well

it suggest to me from my very limited knowledge and guessing that itl be either 3 broken ones and 3 that ran in and sealed even enough. or 1 broken 1 and 2 didnt run in and 3 good ones lol

oh yep. probably lost about $3500 in labour from getting engine put in and bit of other stuff from tuner guy and tune and crap. bottom end cost me $1300 all up oh well. if the shop i was originally going to go with can do this new motor and install it for around the price he said the other day itl be not too bad in the end. which will make this first mechanic bill look REAL BAD

ya maybe. i cant find any pics of the rb30 mahle pistons in particular but on one mahle pistons pics when i type in rb30 on ebay the middle ringlad thing is real thin/small compared to others. dunno