New Engine Blown Up At Tuners

[mico]

make sure u get a torque plate bore and hone even if u are using std head bolts. extremely important.

[AngryRB]

I wouldn't take it much over 6500-7k with standard everything, plus with stock cams and a non stupid sized turbo you don't need to take it over that to make big power.

piston clearance is all based on the pistons being used, they will state what is recommended. Forged are usually quite a bit larger due to expansion.

thats not a bad compromise 6500, be interesting to know what happened with this build.. eventually will be an option for me..

[AngryRB]

make sure u get a torque plate bore and hone even if u are using std head bolts. extremely important.

whats a that?

[mico]

block/bores can deform due to stress on the threads from headstuds and even bolts. its alot of tension. so they bore with a dummy head to keep it round when the real head goes bak on. some workshops wont even release an engine without this being done. nb joblo.

[Rolls]

block/bores can deform due to stress on the threads from headstuds and even bolts. its alot of tension. so they bore with a dummy head to keep it round when the real head goes bak on. some workshops wont even release an engine without this being done. nb joblo.

I remember someone saying the workshop actually refused to do this as they didn't want to make up a dummy head to bolt on due to time money. Certainly want to make sure they do this! if they don't normally do RBs there is a chance they didn't though.

[D_Stirls]

Dummy head is called a torque plate.

OP, was the engine run at all before it went to the dyno and if so how long did it run and what were the running conditions (i.e. idling, driving, rev's etc.)

Personally i think the 1000km run in thing comes from what is require with brand new cars, but with brand new cars you aren't only running in the engine you running in the whole drive train.

[AngryRB]

I remember someone saying the workshop actually refused to do this as they didn't want to make up a dummy head to bolt on due to time money. Certainly want to make sure they do this! if they don't normally do RBs there is a chance they didn't though.

+1 thats a great point, never thought of it before..

[mico]

not many people knew what it was when i rang around either !! only a handful. also get a line bore/hone, very important with a long 6cyl crank !!!

[Rolls]

Dummy head is called a torque plate.

Yeah, I called it that just so he knew what I was talking about.

Make sure you go to an RB specialist when getting RBs built, you want someone who has built 100s before, otherwise you have no guarantee they have any idea what they are doing.

Engine building is not simple, there are 1000s of places to go wrong, and just one of them is enough to grenade an entire motor, when you are spending thousands you want everything to be perfect.

I put more faith in a second hand nissan motor that is unopened for this reason, they built 100s of motors a DAY so they knew what they were doing. Says it all when you see rb30s that are 400,000kms old and still look great when stripped down.

Edited July 31, 2011 by Rolls

[AngryRB]

Yeah, I called it that just so he knew what I was talking about.

Make sure you go to an RB specialist when getting RBs built, you want someone who has built 100s before, otherwise you have no guarantee they have any idea what they are doing.

Engine building is not simple, there are 1000s of places to go wrong, and just one of them is enough to grenade an entire motor, when you are spending thousands you want everything to be perfect.

I put more faith in a second hand nissan motor that is unopened for this reason, they built 100s of motors a DAY so they knew what they were doing. Says it all when you see rb30s that are 400,000kms old and still look great when stripped down.

yeah definitely, there an awesome motor , alot of vl turbos with 200 000km plus still haul

[joe blo]

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

Edited July 31, 2011 by joe blo

[Rolls]

If you get it stripped down by a professional and get them to write a report saying detonation killed it then that is definitely an avenue you can pursue, if it was 100% detonation then you could even pursue him for the cost of a replacement motor, but this would almost certainly involve court. If it can't be 100% proven then do not bother though, and remember as soon as you start pointing fingers they are going to be very reluctant to help you.

[joe blo]

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

[Rolls]

What are all the cars for?

[Al Despo]

Status I agree with what you have said, also my understanding is boost actually helps the rings bed in quicker, but from those compression test results my experience says those rings didn't bed in.

Im confused with the whole running in process in that many experienced people believe in the '1000 kms' approach and that boosting the engine frequently at high rpm is just asking for a rebuild and here from the experienced builders say its all good to boost i guess within reasonable rpm limits and have many many engines to prove that. My question then, is there a clear cut theory to what will definitely cause failure due to rings, bearings etc... during the running in of the engine? Of course the engine cant handle 21psi off the bat but what are the limits?

[lilcrash]

Boost actually forces the rings against the bores so 21psi may not be a damaging factor, on another forum I asked for people's opinions on running in and it all comes down to who you want to put your trust in. I was always impartial to the nice mountain drive with lots of high load pulls up hills and lots of early downshifts to load up down hills. But thats just my own experience as I learnt from my dad. There is lots of different ways to do it.

[tridentt150v]

I always reckoned 'just drive it' like it wasn't any differnt to any other car. But have cool downs for the first 200km. So drive it and don't spare it [but don't flog it] for 10 minutes, then cool down. Then do the same again for 30 minutes, and then 60 minutes. Plenty of cool downs and even a check of everything to make sure you got it right.

Use run in oil and hills all OK. After this you could get it dyno tuned, but I'd also listen to my machinist/engine builder.

I'd also dump my run in oil at 100 and 500. 100 gets all the 'dirt' out, the little impurities and bits of metal that a new engine is bound to have. After 500 you don't need run in oil any more.

And run in oil is better for cast engines, not so necessary for moly or nikasil etc

[STATUS]

Status I agree with what you have said, also my understanding is boost actually helps the rings bed in quicker, but from those compression test results my experience says those rings didn't bed in.

my experience is telling me its det related. not run in related.

[Dobz]

remember the problem started after the first power pull. smoke came out the back (think he said that) and he saw it coming out under the bonnet. it wasnt oil covered in the engine bay when i picked it up. it was just puffing white smoke out the breathers.

i gave it one pull through 2nd and abit of 3rd on the way home. and one quick one in second up a hill and when i got home theres oil everywhere.

i dont think we can blame it on the machinist boring and honing and stuff. its where the guy that tuned it gets his machine work done for his race engines that he mainly does.

just started it when i got home a few minutes ago and the white smoke sorta chugs out in quick breath sorta things in time with the engine. like its not continous sorta thing.

head is a rebuilt one new for this motor. was a $750 rebuild so whatever that price one usually does it what got done.

the rings were VERY brittle when i was putting them on the pistons. i broke one coz i put it on upside down. it was a bottom one and i tried to open it up to go over the top one that was already installed and it broke so easily. maybe they dont like 450rwhp. its weird to me that it would happen on the very first power run. like to me that maybe suggests 1 or more rings might have broken. but i dont know how brittle standard nissan ones or any other ones are to compare to. i did think to myself that i thought they might not like big power coz i snapped the one i broke a few times after i broke it initially to get an idea of the metal integrity

thanks to the good dudes so far. to the homos. yous stink

Did anyone else read this part or is it just me?

I'm very sure cro-moly rings aren't supposed to break like that. What happened with replacing that ring, where did you get it from?

[joe blo]

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