R34 GTT - Bottom end build question

[LjB123]

Hey guys. Really would love some guidance here, im stuck between a rock and a hard place and makes me sick that ive just had one thing after another go wrong on a car I purchased a month ago.  
 

Initially showed an exhaust valve leak from a leak down test, got head off, serviced, machined, replaced a few valves that needed replacing and all the guides, upgraded springs and retainers, upgraded cams to Poncam Type B’s, put it all back together. Popped it on the dyno, made only 180kw at 20PSI of boost. Power dipped at peak torque, so not good. They found it had a slight knock on a cold startup, but went away after a couple seconds. Dropped the oil, and found little bits of metal in the oil and oil filter, great! So bottom end needs some attention now. They didnt want to just replace whats broken, they wanted to go all out forged internals (pistons, rods, rings, crankshaft), get it machined, new oil pump, gaskets, bearings, the lot. Reckon it would come to about $20,000 with a tune after all back together. Im not after a ridiculous build. Its a weekend car to enjoy driving and cruising, im not wanting to make 500kw at the wheels. Reason they wanted to do all new parts is so they could cover their workmanship under their warranty, if something old that wasnt replaced broke, it could become a big thing
 

Can i get some guidance on what I should do here? This is my first time getting into this stuff and the car has just been an absolute shit show from the get go, and makes me sick thinking how ive purchased this car and the engine needs to come out. There were no signs of this from the beginning that it had a bottom end issue, and i have not even driven it 400kms since buying it

[Duncan]

Yeah, that does suck, sorry to hear. And it is possible the seller knew there was an issue but you didn't realise too.

Bottom line is, you choose what work you do to repair it based on your budget. The workshop advice is good for a "proper" fix, but you absolutely have a path where you can slap a second hand bottom end under it and go again. Depending how much work you can do yourself it is probably a 5-20k range so in the real world, what you can afford to spend on the car matters.

[Murray_Calavera]

Sorry mate, that is pretty shit. I'd almost guarantee the seller knew about these issues when the car was sold too...

To give some proper advice, we'll need some more details to be able to make a proper recommendation. 

How much power do you want to reliably make? 

Will the car see track use? Will you use R comp tyres, do any drifting, or use anti lag/2step? etc?

[robbo_rb180]

Damn, that is the worst thing. 
@admS15 just did a home rebuild on a budget with good success.
Have read from here:

Pending damage done and budget can get away with second hand pistons and a quick hone.
There could be damage to crank and mains too which will need engine out to see and more machining.
Budget will determine how you go fixing but removing and refitting the engine yourself can save a few $$$$ but can come with certain disclaimers from engine builder. With the way the market is there has been a few decent second hand engines around SE Qld that could be had for reasonable money but its another gamble.

https://www.facebook.com/marketplace/item/206185355874299/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A7074d731-18c6-435a-96d8-a0f886389be1
https://www.facebook.com/marketplace/item/24721780230801011/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A7074d731-18c6-435a-96d8-a0f886389be1


@No Crust Racing you want to build another motor???

[LjB123]

1 hour ago, Duncan said:

Yeah, that does suck, sorry to hear. And it is possible the seller knew there was an issue but you didn't realise too.

Bottom line is, you choose what work you do to repair it based on your budget. The workshop advice is good for a "proper" fix, but you absolutely have a path where you can slap a second hand bottom end under it and go again. Depending how much work you can do yourself it is probably a 5-20k range so in the real world, what you can afford to spend on the car matters.

I would love to have 300kw at the wheels, it has all the supporting mods for it, and now with a serviced head with some upgrades should be better. I can get a second hand Neo motor with 180,000kms on it, and 160-170 psi compression on all cylinders for $5000, and can likely sell some parts to make some money back. It came out of a stock R34 and was taken out shortly after he got the car a month or so ago because he had an already built RB ready to go in. Would save some money to swap the bottom end of that over, likely would get some new bearings and other basic parts before it goes in. Still not sure what i want to do exactly 

Edited February 20, 2024 by LjB123

[LjB123]

1 hour ago, Murray_Calavera said:

Sorry mate, that is pretty shit. I'd almost guarantee the seller knew about these issues when the car was sold too...

To give some proper advice, we'll need some more details to be able to make a proper recommendation. 

How much power do you want to reliably make? 

Will the car see track use? Will you use R comp tyres, do any drifting, or use anti lag/2step? etc?

Well the cars set up to make 300kw at the wheels comfortably, previous owner has dyno papers for those figures. High flowed turbo, intake plenum, upgraded intake system, injectors, fuel pump, haltech ECU, spitfire coils. Car is my dream car, unfortunately my dream has been a nightmare so far, and is a weekend warrior for just road use cruising and enjoying the drive, with a bit of fun giving it a boot. Would get driven maybe every couple weekends. The head is freshly serviced, machined, new valve guides, replaced 5 valves as needed, upgraded springs and retainers, poncam type B cams, so head is good to go on current motor. As mentioned to others in other replies, I can get a second hand Neo motor with 180,000kms on it, and 160-170 psi compression on all cylinders for $5000, and can likely sell some parts to make some money back. It came out of a stock R34 and was taken out shortly after he got the car a month or so ago because he had an already built RB ready to go in. Would save some money to swap the bottom end of that over, likely would get some new bearings and other basic parts before it goes in. Still not sure what i want to do exactly 

[LjB123]

34 minutes ago, robbo_rb180 said:

Damn, that is the worst thing. 
@admS15 just did a home rebuild on a budget with good success.
Have read from here:

Pending damage done and budget can get away with second hand pistons and a quick hone.
There could be damage to crank and mains too which will need engine out to see and more machining.
Budget will determine how you go fixing but removing and refitting the engine yourself can save a few $$$$ but can come with certain disclaimers from engine builder. With the way the market is there has been a few decent second hand engines around SE Qld that could be had for reasonable money but its another gamble.

https://www.facebook.com/marketplace/item/206185355874299/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A7074d731-18c6-435a-96d8-a0f886389be1
https://www.facebook.com/marketplace/item/24721780230801011/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3A7074d731-18c6-435a-96d8-a0f886389be1


@No Crust Racing you want to build another motor???

Ive said this to others in reply, but  I can get a second hand Neo motor with 180,000kms on it, and 160-170 psi compression on all cylinders for $5000, and can likely sell some parts to make some money back. It came out of a stock R34 and was taken out shortly after he got the car a month or so ago because he had an already built RB ready to go in. Would save some money to swap the bottom end of that over, likely would get some new bearings and other basic parts before it goes in. 
 

Unfortunately for me i don’t have heaps of spare time otherwise i would look at doing some work myself. I run a one man fabrication and welding shop and time is precious. The car was meant to be just a weekend car for fun, no track or drift, want to keep it as long as i can as an R34 is my dream car since playing need for speed on my playstation 2. Previous owner had done all supporting mods to make 300kw at the wheels, and now ive done all head work with some upgrades, it will be even better. 
 

Not sure on what is the best way to approach this, the car wont get driven heaps, and the hardest driving it will get is on the road, no drifting or silly business except for soms pulls every now and then

[GTSBoy]

Buy the stock motor.

While it is apart to put the head on it, do:

Nitto oil pump. Add extra restrictors to the head as required.

Front and rear crank seals, water pump, timing belt.

Any water or oil hoses on the driver's side and wrt the turbo that look anything other than new and flexible.

A very good head gasket. Nitto head bolts.

Thermostat.

Clean out all coolant passages that you can easily see anywhere. Neglected Neos can get sludge built up in the hoses to and from and the inside of the IACV at the rear of the stock plenum. Makes bleeding difficult.

New balancer.

What is the ECU? If not stock, then now is the time to put a different crank and cam sensor on it to get more reliable timing.

 

If you're going to go with the rebuild of your dead motor, I'm more with the shop than with your desire to not spend on it. At the very least it will want pistons. Rods are cheap these days, so that's them too. The rest of it pretty much needs and wants to be done even if you were to cheap out on stock pistons and rods. All the spanner work, cleaning, machining, bearings and resizings of things all need to be done.

[Murray_Calavera]

37 minutes ago, LjB123 said:

Well the cars set up to make 300kw at the wheels comfortably, previous owner has dyno papers for those figures. High flowed turbo, intake plenum, upgraded intake system, injectors, fuel pump, haltech ECU, spitfire coils. Car is my dream car, unfortunately my dream has been a nightmare so far, and is a weekend warrior for just road use cruising and enjoying the drive, with a bit of fun giving it a boot. Would get driven maybe every couple weekends. The head is freshly serviced, machined, new valve guides, replaced 5 valves as needed, upgraded springs and retainers, poncam type B cams, so head is good to go on current motor. As mentioned to others in other replies, I can get a second hand Neo motor with 180,000kms on it, and 160-170 psi compression on all cylinders for $5000, and can likely sell some parts to make some money back. It came out of a stock R34 and was taken out shortly after he got the car a month or so ago because he had an already built RB ready to go in. Would save some money to swap the bottom end of that over, likely would get some new bearings and other basic parts before it goes in. Still not sure what i want to do exactly 

Lots of good advice in here already. 

I'll just add, before you feel like you 'need' to do XYZ, just remember there are plenty of 100% stock RB25's out there making 300kw living a perfectly happy life with the use case your describing. 

[LjB123]

38 minutes ago, GTSBoy said:

Buy the stock motor.

While it is apart to put the head on it, do:

Nitto oil pump. Add extra restrictors to the head as required.

Front and rear crank seals, water pump, timing belt.

Any water or oil hoses on the driver's side and wrt the turbo that look anything other than new and flexible.

A very good head gasket. Nitto head bolts.

Thermostat.

Clean out all coolant passages that you can easily see anywhere. Neglected Neos can get sludge built up in the hoses to and from and the inside of the IACV at the rear of the stock plenum. Makes bleeding difficult.

New balancer.

What is the ECU? If not stock, then now is the time to put a different crank and cam sensor on it to get more reliable timing.

 

If you're going to go with the rebuild of your dead motor, I'm more with the shop than with your desire to not spend on it. At the very least it will want pistons. Rods are cheap these days, so that's them too. The rest of it pretty much needs and wants to be done even if you were to cheap out on stock pistons and rods. All the spanner work, cleaning, machining, bearings and resizings of things all need to be done.

What advantage will the nitto oil pump have over a OEM one? And what advantage will restrictors have?

 

New water pump and timing belt are done, were sorted with the heads that i just had serviced and machined, same with new nitto head gasket and ARP studs. ECU is a haltech platinum

[Murray_Calavera]

12 minutes ago, LjB123 said:

What advantage will the nitto oil pump have over a OEM one? And what advantage will restrictors have?

 

New water pump and timing belt are done, were sorted with the heads that i just had serviced and machined, same with new nitto head gasket and ARP studs. ECU is a haltech platinum

The Nitto oil pump is much stronger compared to factory. It also flows substantially more compared to the factory pump, the restrictors and needed in the head due to the increased flow/pressure provided from the upgraded pump. 

If you upgrade the oil pump, to do it properly, you would also upgrade the sump (larger capacity and baffled) and improve the oil return (breathers back to the sump, and possibly an additional oil drain from the head). 

[GTSBoy]

17 minutes ago, LjB123 said:

What advantage will the nitto oil pump have over a OEM one? And what advantage will restrictors have?

Stock oil pump on a Neo is the N1, and is ..... OK. But only OK. My position on rebuilding an RB is that no RB should be rebuilt with the original oil pump. You need more volume and pressure.

And.... then you need to restrict the amount of oil that the pump will deliver to the head, hence the restrictors.

[GTSBoy]

19 minutes ago, LjB123 said:

ECU is a haltech platinum

So this should drive the ability to upgrade the triggering system. Your tuner will thank you for it, as will your engine.

[LjB123]

4 minutes ago, GTSBoy said:

Stock oil pump on a Neo is the N1, and is ..... OK. But only OK. My position on rebuilding an RB is that no RB should be rebuilt with the original oil pump. You need more volume and pressure.

And.... then you need to restrict the amount of oil that the pump will deliver to the head, hence the restrictors.

Yeah fair enough. Restrictors require drilling and tapping don’t they?

[LjB123]

5 minutes ago, Murray_Calavera said:

The Nitto oil pump is much stronger compared to factory. It also flows substantially more compared to the factory pump, the restrictors and needed in the head due to the increased flow/pressure provided from the upgraded pump. 

If you upgrade the oil pump, to do it properly, you would also upgrade the sump (larger capacity and baffled) and improve the oil return (breathers back to the sump, and possibly an additional oil drain from the head). 

Would all that be necessary on a street car that gets driven every couple weekends and 5000kms a year?

[admS15]

Firstly, sorry this has happened to you and just doesn't make sense the way its gone down. 

Tbh if I where you, given everything you've already done and where you've landed. I'd have that bottom end pulled apart and inspected before buying the 2nd hand bottom end. I'd want confirmation that something is actually really f**krd and to what extent. Engine is going to have to come out either way and head etc. is going to be pulled, an extra hour or 2 labour to disassemble the bottom end isn't adding much to the cost.

Depending on the severity make your decision. In your situation, I'd be more inclined to do the proper forged rebuild than spending 5k on a 25 year old bottom end. 

As Rob said earlier, I did do a budget rebuild with success. Rebuild consisted of new rings, bearings, home hone job, forged rods with arp bolts. The thing is the bottom end was virtually donated to me for a slab of beer and total cost was around $1500 and many many hours. If I had to spend 5k on a starting point for a 2nd hand motor, I would have just coughed up for the forged bottom end rebuild.

I'm going to go against the grain here and disagree with using a nitto pump on a 300kw street car that won't see a track frequently. My original unopened engine lasted 8 years at 315rwkw did heaps of track days and when it did finally let go, it wasn't due to an oiling issue. Twas a rod bolt that decided enough was enough. Nitro pump is better, not disputing that but totally unnecessary for street application. Flame suit on boys.

I also have a question about how the car drove when you first got it. Did it feel like 300kw vs say now that it only has 180kw? It should be a massive difference.

[Murray_Calavera]

14 minutes ago, LjB123 said:

Yeah fair enough. Restrictors require drilling and tapping don’t they?

Nah, it's an interference fit. Just tap it in (with a hammer, not a threaded tap). 

 

13 minutes ago, LjB123 said:

Would all that be necessary on a street car that gets driven every couple weekends and 5000kms a year?

Well, it's up to you. My car makes about 350kw, it has a 100% factory engine. Stock gasket, studs, everything. I've had this setup for many years. When my car sees the track, I treat it with A LOT of mechanical sympathy. So far so good. 

I could talk about this for ages, but the short version is, your ECU when properly setup will go a long way in saving your motor. 

I've had my engine protection trigger I think about 3 or 4 times now, one of those events would have been catastrophic had I not setup my engine protection, so I can safely say my ECU has saved my motor at least once. 

[LjB123]

16 minutes ago, admS15 said:

Firstly, sorry this has happened to you and just doesn't make sense the way its gone down. 

Tbh if I where you, given everything you've already done and where you've landed. I'd have that bottom end pulled apart and inspected before buying the 2nd hand bottom end. I'd want confirmation that something is actually really f**krd and to what extent. Engine is going to have to come out either way and head etc. is going to be pulled, an extra hour or 2 labour to disassemble the bottom end isn't adding much to the cost.

Depending on the severity make your decision. In your situation, I'd be more inclined to do the proper forged rebuild than spending 5k on a 25 year old bottom end. 

As Rob said earlier, I did do a budget rebuild with success. Rebuild consisted of new rings, bearings, home hone job, forged rods with arp bolts. The thing is the bottom end was virtually donated to me for a slab of beer and total cost was around $1500 and many many hours. If I had to spend 5k on a starting point for a 2nd hand motor, I would have just coughed up for the forged bottom end rebuild.

I'm going to go against the grain here and disagree with using a nitto pump on a 300kw street car that won't see a track frequently. My original unopened engine lasted 8 years at 315rwkw did heaps of track days and when it did finally let go, it wasn't due to an oiling issue. Twas a rod bolt that decided enough was enough. Nitro pump is better, not disputing that but totally unnecessary for street application. Flame suit on boys.

I also have a question about how the car drove when you first got it. Did it feel like 300kw vs say now that it only has 180kw? It should be a massive difference.

Appreciate the insight. Thing is new rods, pistons, rings and crank that are forged will set me back about $5-7000 before any labour is involved, not including all the other components 

I have never experienced driving a 300kw car to be honest. Current mechanic that has it put it on the dyno after the fresh heads were done and reinstalled is the only one whose driven it since the work. Basically when i found out that theres an exhaust valve leak, i didnt start it up except for taking it to get the head work done. Now we have discovered the bottom end is causing issues, i will be towing it from the current mechanic. Im likely switching to a more local mechanic and tuner, just because hes been super helpful to me and initially identified the exhaust valve leaks with a leak down test, only reason i didnt go with them in the first place was because they were super busy getting 3 cars ready for Rally Sprint at Eastern Creek, and i was keen to get my car going again and enjoying it. Now im just left with a whole lot less money and a whole lot of disappointment, not that a different mechanic and tuner would make any difference to how my engine is

Edited February 20, 2024 by LjB123

[LjB123]

12 minutes ago, Murray_Calavera said:

Nah, it's an interference fit. Just tap it in (with a hammer, not a threaded tap). 

 

Well, it's up to you. My car makes about 350kw, it has a 100% factory engine. Stock gasket, studs, everything. I've had this setup for many years. When my car sees the track, I treat it with A LOT of mechanical sympathy. So far so good. 

I could talk about this for ages, but the short version is, your ECU when properly setup will go a long way in saving your motor. 

I've had my engine protection trigger I think about 3 or 4 times now, one of those events would have been catastrophic had I not setup my engine protection, so I can safely say my ECU has saved my motor at least once. 

Ok thats all good to know. I do believe there are some engine protections in place. The guy the car is with at the moment did say there are some sensors installed and wired in with the ECU to help with engine protection

[Murray_Calavera]

8 minutes ago, LjB123 said:

I have never experienced driving a 300kw car to be honest

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

7 minutes ago, LjB123 said:

I do believe there are some engine protections in place

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.