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Rb25 Rebuild Advice

rb25_gtst

By rb25_gtst,
in New South Wales

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rb25_gtst Contributor

rb25_gtst

Posted
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Well first of all I will apologize if I have posted yet another rebuild topic, but I haven't had time to search the forums for the appropriate post.

Ok, well I have a 95 R33 gts-t with 160,000kms which is lightly modified, nothing spectacular.

It makes 186kw on 12psi and I am definitely chasing more but before I can go further I'm convinced my motor needs to be rebuilt.

My question is this. How much for parts & labour and roughly how long will the rebuild process take as it is my only means of transportation and I don't want to take too much time off work. Also any engine rebuilders that you wish to recommend I would appreciate it.

I am only looking to achieve around 250rwkw, so any rebuild kit that is capable of that kind of power and still be reliable would be fine.

Thanks.

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Sinful Grand Master

Sinful

Posted
Posted

Our rebuilds have taken from 2 weeks to 3 months depending on what parts you want to put in the motor and if you are going to get balancing done and that sort of thing as most of the time parts need to be sent off to other places :D ???

If you are going for a stock rebuild shouldn't be to expensive and wont take long but if you are going to upgrade parts well depend what you want to do...

I would ring around some workshops and get prices and go from there might not know what you need till you open the motor up?? >_<

rb25_gtst Contributor

rb25_gtst

Posted
  • Author
Posted

Well I dunno about the previous owner but in my care it has not been neglected or abused.

Ok, well I'm not absolutely 100% positive the engine needs to be rebuilt but I don't want to spend the money on a bigger turbo, injecters etc to increase the power just to have the motor explode.

So my aim is to just buy some forged pistons and rods, new bearings,head gasket, cams, cam gears and have the crankshaft balanced etc..etc and just pay someone to disassemble and reassemble it, and of course tune it.

After all that, then add the turbo.

I'm going to have the engine compression tested next week and I'll let you know the result.

My main reason for concern about the engine is that after Advan installed and tuned the Power FC, knock levels were consistently high, was possibly leaning out, don't have an AFR gauge. So we had to disconnect the E-Boost and put it back to standard, runs fine now, but slow.

Also just wondering what you guys think of the X-Force low mount manifolds, I have one on my car now which has warped and is leaking although it didn't sit perfectly on the head to begin with. And if you're wondering why they put it on my car in the first place if it didn't sit right is beucase upon removal of the standard one they broke every stud and they were stuck in the standard manifold and couldn't re-use it without more labour which I didn't want to pay for.

Yeah so.. that's the kind of rebuild I'm after. I would probably even settle for genuine nissan parts.

Thanks for readin'

ECR033 Mentor

ECR033

Posted
Posted

Get the compression test done (and a leak down test if you want peace of mind), then decide if you need the rebuild. Both tests should give a good indication of the condition of your motor.

If you're currently getting high levels of knock, then it's probably the result of poor tuning, probably running too much boost and your stock injectors maxing out. Given that the car is fine on lower levels of boost, I'd say it's less likely that there's something wrong with your motor.

I'd recommend that you go back to your tuner and get them to adjust the tune before you do some damage and end up melting a piston - you'll then need a rebuild if that happens. It's not unusual to have to get a tuner to make small adjustments after an initial tune as they can't simulate all driving conditions on a dyno.

My car has 280rwkw+ on standard internals for quite a while now and hasn't missed a beat. I wouldn't recommend wasting money on a rebuild if you don't need to unless you're chasing well over 300rwkw.

wilch Grand Master

wilch

Posted
Posted

ECR033 is right. I have similar power to him with standard internals, and I track my car.

Your problems seem to be tune related, and this business about not fixing the exhaust manifold properly because you didn't have enough money seems really silly.... If you have enough money for a rebuild, you have enough money to fix the exhaust manifold.

If it's warped, then it's leaking, and that'll cause you some issues.

Just get a leakdown test and compression test done. If all's good spend the money on fixing up that exhaust manifold, buying a new turbo and getting it tuned properly. You should easily get to 250rwkW and not have any issues with the engine.

rb25_gtst Contributor

rb25_gtst

Posted
  • Author
Posted

At the time I didn't have the money but now I have a credit card!, which is going to pay for all the components, as for the manifold I'm gonna get another one under warranty.

For my next tune I think I'll go to SAS, I've heard good things.

What mods did you guys use to achieve 250+kw wilch & ECR033???

wilch Grand Master

wilch

Posted
Posted

...or thereabouts :)

Engine's still going strong too.

Dropped 10rwkW at the last dyno day due to a dodgey thermostat and a blocked radiator (pfc retard maps @ 100degrees celcius... bah!). It's been back to normal for a while now. woohoo :(

See you've got two options Craig (if the leak down and compression comes back aok), do what ECR and I did, or rebuild and end up with around about 220rwkW and an engine that can put out over 300rwkW if you add $6k to the $15k you would have already spent rebuilding the engine.

15k+6k = a straight 32 GTR that may need a rebuild within a year....

Lots of sums to do, lots of things to consider.

rb25_gtst Contributor

rb25_gtst

Posted
  • Author
Posted

Thanks for all the input guys... and so promptly too.

If the compression & leak down tests show that the engine is fine, how many more K's should I expect to get out of it before it does require a rebuild?? (Currently at 160,XXX).

And worst case scenario, the tests reveals the worst. Do you think I could get away with just replacing the bearings, rods & pistons and leaving the rest as it is provided the other stuff is ok?? Maybe adding some adjustable cam gears if I get credit card happy.

Also, I'm going to Just Jap today to get my manifold replaced under warranty, you guys know anyone/anyplace that could install it for a reasonable price and is available soonish.

Thanks again everyone.

GoldZilla Grand Master

GoldZilla

Posted
Posted

Treat it right, keep it properly tuned and regularly serviced, and don't thrash it at EVERY SINGLE opportunity and it should last for ages (not sure how many kays, though, sorry).

There is a Stagea owner here who also owns an R30 Skyline that has done over 350,000kms with (as far as I know) the original L-series motor. Nissan engineering is pretty sturdy, so there's no reason you couldn't expect to at least reach 200,000 at a minimum if you treat it right.

ECR033 Mentor

ECR033

Posted
Posted
What mods did you guys use to achieve 250+kw wilch & ECR033???

If you look one post above Wilch's mods in the link below, you'll see my mods.

Make sure you don't forget to factor in labour costs when budgeting your mods...labour is a huge component of the total cost.

Like Goldzilla said, if you service your car regularly, the tune is good and you don't drive like a tool, then there's no reason why the motor won't last for a long while yet provided that it's in good condition at the moment.

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