R34 GTT - Bottom end build question

[admS15]

Fair enough mate. Good call on sending car elsewhere. As I said something doesn't make sense here and someone else taking over may answer a few questions or confirm what shop a has said.

Crank will more than likely be salvageable with a linish and doesn't need upgrading. They can handle pretty big power without issue. 

You can get a spool kit like this for reasonable money. https://www.spoolimports.com/conrod-piston-deal/spool-rb25-neo-conrods-and-ross-forged-pistons?gad_source=1&gclid=CjwKCAiAuNGuBhAkEiwAGId4aheIUpkSk8p4WcqiPjrHVtQMD2GMG8t37rXkX6hfikjFRQZ-ohSbvhoC-DoQAvD_BwE

You already have a serviced head, head studs, timing kit and gasket. Add a few K in for machining and assembly. Will be over 5 k but will also have a known brand spanking new forged bottom end. 

[LjB123]

Just now, Murray_Calavera said:

But when you bought the car, wasn't it making 300kw at the time? Or did I misread something previously?

You can verify this with 5 seconds of your time and a laptop. I wouldn't be surprised if none of the engine protection was turned on. Even if you have no interest in learning to tune yourself, please at least plug a laptop in and see what has been setup... or hasn't been. It costs you nothing, takes almost no time and could save your motor. 

Well according to the previous owners dyno sheet from when he originally did the build, yes it was 300kw. I never got it dyno’d myself after buying it until the works were done. The tuner its at now said the engine protection is on

[LjB123]

2 minutes ago, admS15 said:

Fair enough mate. Good call on sending car elsewhere. As I said something doesn't make sense here and someone else taking over may answer a few questions or confirm what shop a has said.

Crank will more than likely be salvageable with a linish and doesn't need upgrading. They can handle pretty big power without issue. 

You can get a spool kit like this for reasonable money. https://www.spoolimports.com/conrod-piston-deal/spool-rb25-neo-conrods-and-ross-forged-pistons?gad_source=1&gclid=CjwKCAiAuNGuBhAkEiwAGId4aheIUpkSk8p4WcqiPjrHVtQMD2GMG8t37rXkX6hfikjFRQZ-ohSbvhoC-DoQAvD_BwE

You already have a serviced head, head studs, timing kit and gasket. Add a few K in for machining and assembly. Will be over 5 k but will also have a known brand spanking new forged bottom end. 

Theyre the kit a mate of mine recommended to get if i go down that track. Appreciate the help, and will keep you guys updated on how it all goes and what happens. Unfortunately i don’t think it will get pulled apart for a couple weeks at this rate with the work load they have on

[Murray_Calavera]

2 minutes ago, LjB123 said:

Well according to the previous owners dyno sheet from when he originally did the build, yes it was 300kw. I never got it dyno’d myself after buying it until the works were done. The tuner its at now said the engine protection is on

But didn't you drive it before you bought it? I'm guessing it was driving fine at the time you bought it?

[LjB123]

2 minutes ago, Murray_Calavera said:

But didn't you drive it before you bought it? I'm guessing it was driving fine at the time you bought it?

Owner took me for a drive. He didnt drive it super hard when taking me for a drive. Started fine, ran fine, didnt think much would be wrong with it. When i drove it, it felt powerful, pulled hard when i gave it a boot, despite the turbo coming on fairly late at 4500rpm (owner’s preference). I would have been none the wiser besides the fact i decided to get a local mechanic/tuner to give it a full go over and service. Previous owner seemed legit, he also had an R32 GTR weekend car, didnt drive this one much anymore, was wanting to either get in the market for a R34 GTR, or have some extra money for his wedding later this year, so wanted to sell this. All work had been done 8000kms ago, was pretty much dead stock before, and i can see from his rego history the car was barely driven since he owned it and did all the work

[GTSBoy]

Whilst all of that ^ could be totally innocent, taken together it sounds like all the alarm bells ringing. You're just going to have to go forwards, not look backwards.

[LjB123]

7 hours ago, GTSBoy said:

Whilst all of that ^ could be totally innocent, taken together it sounds like all the alarm bells ringing. You're just going to have to go forwards, not look backwards.

Alot of people don’t let others test drive the car, so wasnt a hige alarm bell to me

[Duncan]

Well, the key thing is still your budget (and time, but you've said you don't have much), and the fact you are happy with the existing 300kw for now.

If I were you I'd buy the 5k engine, sell the head (probably for 5k these days as its a 25 NEO), swap your head onto it and send it. 

Then, as funds allow, collect parts to rebuild your now spare bottom end properly.

[LjB123]

58 minutes ago, Duncan said:

Well, the key thing is still your budget (and time, but you've said you don't have much), and the fact you are happy with the existing 300kw for now.

If I were you I'd buy the 5k engine, sell the head (probably for 5k these days as its a 25 NEO), swap your head onto it and send it. 

Then, as funds allow, collect parts to rebuild your now spare bottom end properly.

You can be fully serviced Neo heads for $3000 online, so don’t think i will quite get $5000 for it. I would probably end up just keeping the head for a worst case scenario down the line, best case is i have a new head to upgrade if something happens to the current one in the future, as i imagine these will get harder and harder to find

[Dose Pipe Sutututu]

Your NEO head is worth quite a bit of coin, and since it has been serviced it is already in tip top condition. You could sell that and you'll have only a small shortfall for a used 2nd hand NEO motor.

Slap on a new head gasket, using major service kit, a few new seals here and there and you'll have a very capable motor to do 300kW ~ 400kW all day.

[LjB123]

32 minutes ago, Dose Pipe Sutututu said:

Your NEO head is worth quite a bit of coin, and since it has been serviced it is already in tip top condition. You could sell that and you'll have only a small shortfall for a used 2nd hand NEO motor.

Slap on a new head gasket, using major service kit, a few new seals here and there and you'll have a very capable motor to do 300kW ~ 400kW all day.

My NEO head has new valves, valve guides, upgraded springs and retainers, upgraded cams, and all new gaskets, i don’t see why it would be a good idea to put in a second hand stock head? Stock valve spring don’t like handling much past 18PSI of boost comfortably, so would be silly to downgrade to a stock head I would think?

[Dose Pipe Sutututu]

Just now, LjB123 said:

My NEO head has new valves, valve guides, upgraded springs and retainers, upgraded cams, and all new gaskets, i don’t see why it would be a good idea to put in a second hand stock head? Stock valve spring don’t like handling much past 18PSI of boost comfortably, so would be silly to downgrade to a stock head I would think?

 

It was just more what will require the least effort & cost to get your car doing 300kW.

If this was my car, I would just get a basic forged kit and fit it up, and if your bores aren't scored and within spec just get 86mm pistons so there's no need to bore out the block.

No idea who gave you that $20k quote, however it can be done sensibly for much less.

[LjB123]

I found a stock bottom end for $2000 which i might get instead of spending $5000 on a whole engine. No scoring, and crank and pistons feel solid with no play or movement so likely bearings are good in it. He said i can pull the sump off to take a look. Just need to decide do i spend $5000 for a whole engine and i will have basically a whole engine i can modify outside the car for a high power build in the future. RB25DET Neo heads arent getting any easier to find, and likely Nissan wont do the heritage thing they are doing for GTR components

[Dose Pipe Sutututu]

for $2000, that's not too bad in today's market.

Perhaps go to a local engine builder and get new rings/bearings put in and send it.

[No Crust Racing]

Haven't read the full thread but got tagged so here I am, sorry to hear this happened. 

Cheapest path forward is almost always buying a used running bottom end and putting your head on it or just buying a good used running motor and selling your head/keeping as spare. 

Bills $1500 build is stuff of legends honestly, I am no slouch at finding stuff online and my XR5 rebuild was still over 4k re-using stock rods and pistons, but including machining and a replacement crank etc and that was doing the labour myself - machining was an easy $1500. I did do new water pump, timing, every seal etc etc but it adds up fast. 

Forged build is always going to be 10-20k, depending on parts used etc. 

You do not want to use much of that bottom end now it's had bearing go through it, if it has an oil cooler that's in the bin, check the pump for scoring etc so you may have to replace a lot of that stuff out of necessity (turbo also) depending on how much bearing material and how long. It cannot be overstated how critical cleaning is after a bearing failure, not just a hot tank, oil gallery plugs out, manually cleaning with brushes, compressed air, and tons of brake cleaner.

Not sure I'd want to do another build on an engine that spun a bearing unless I was not using a lot of the parts. 

Full disclosure, not a mechanic or engine builder and I don't know heaps about RBs anyway, take all this with a grain of salt. 

Your budget and timeline will determine best course of action, how much do you want to spend to fix this issue and how long can the car be off the road? 

P.S. Didn't even check this for typos... 

[GTSBoy]

52 minutes ago, No Crust Racing said:

P.S. Didn't even check this for typos... 

You'd be one of the few, if you hda.

[LjB123]

On 23/2/2024 at 4:20 PM, No Crust Racing said:

Haven't read the full thread but got tagged so here I am, sorry to hear this happened. 

Cheapest path forward is almost always buying a used running bottom end and putting your head on it or just buying a good used running motor and selling your head/keeping as spare. 

Bills $1500 build is stuff of legends honestly, I am no slouch at finding stuff online and my XR5 rebuild was still over 4k re-using stock rods and pistons, but including machining and a replacement crank etc and that was doing the labour myself - machining was an easy $1500. I did do new water pump, timing, every seal etc etc but it adds up fast. 

Forged build is always going to be 10-20k, depending on parts used etc. 

You do not want to use much of that bottom end now it's had bearing go through it, if it has an oil cooler that's in the bin, check the pump for scoring etc so you may have to replace a lot of that stuff out of necessity (turbo also) depending on how much bearing material and how long. It cannot be overstated how critical cleaning is after a bearing failure, not just a hot tank, oil gallery plugs out, manually cleaning with brushes, compressed air, and tons of brake cleaner.

Not sure I'd want to do another build on an engine that spun a bearing unless I was not using a lot of the parts. 

Full disclosure, not a mechanic or engine builder and I don't know heaps about RBs anyway, take all this with a grain of salt. 

Your budget and timeline will determine best course of action, how much do you want to spend to fix this issue and how long can the car be off the road? 

P.S. Didn't even check this for typos... 

the block I found for $2000 was from a engine that had blown a head gasket, is there a way to tell if there is damage done from the blown head gasket? The seller says the bores are not scored at all and the tolerances at the rod end indicate no spun bearings. I was going to pull the sump off and take a look at it to confirm. Just concerned that the blocks structure could be compromised from a blown head gasket and possible over heating? Or am I overthinking this? 
 

I was going to be doing as many new parts as I can like heater core, oil pump, oil cooler, but not sure about the turbo as that is a huge chunk of the expense, and it currently has a high flowed factory turbo and didnt want to go upgrading the turbo just yet as that will mean new manifold, new dump, and likely a whole lot of fabrication work to the intake, and i just want the car running again to enjoy it, as currently its been in the workshop for as long as ive owned the f!@&king thing, but was going to have it cleaned out properly and the shop that will be doing the work is confident in cleaning it all up. But shouldnt the oil filter have caught pretty much all of it?

[GTSBoy]

7 minutes ago, LjB123 said:

But shouldnt the oil filter have caught pretty much all of it?

No. If there is loose metal, then it will be stuck all over the place. And if/when it shakes loose after the rebuild, it will cause damage to your new stuff. It's not to be contemplated.

[Dose Pipe Sutututu]

Barra conversion seems cheaper right now lol.

(Ignore what I said).

[No Crust Racing]

2 hours ago, LjB123 said:

the block I found for $2000 was from a engine that had blown a head gasket, is there a way to tell if there is damage done from the blown head gasket? The seller says the bores are not scored at all and the tolerances at the rod end indicate no spun bearings. I was going to pull the sump off and take a look at it to confirm. Just concerned that the blocks structure could be compromised from a blown head gasket and possible over heating? Or am I overthinking this? 
 

I was going to be doing as many new parts as I can like heater core, oil pump, oil cooler, but not sure about the turbo as that is a huge chunk of the expense, and it currently has a high flowed factory turbo and didnt want to go upgrading the turbo just yet as that will mean new manifold, new dump, and likely a whole lot of fabrication work to the intake, and i just want the car running again to enjoy it, as currently its been in the workshop for as long as ive owned the f!@&king thing, but was going to have it cleaned out properly and the shop that will be doing the work is confident in cleaning it all up. But shouldnt the oil filter have caught pretty much all of it?

Yes deck surface can have soft spots, you would ideally check it for hardness (quick/cheap) but these blocks are not as prone to that as others.

Guarantee you the shop will not clean it enough, it's your job to ensure its minty fresh clean as it's your wallet.

 

Oil filter is not designed to filter that level of debris, oil coolers really cannot be cleaned out properly.

 

You will want to have the turbo inspected at minimum incase it's already scored and I strongly suggest fitting Inline filter to the feed.