Jump to content
SAU Community

Recommended Posts

hey guys my skyline has hit 170,000 and the bottom end has decided to turn into a oil chewer it does 800km and drink 4.2liters of 40/70 :thumbsup:

yes thats right its ruined, anyway my uncle has gone over the car and all i need is to get new cams and he recommends changing my bottom end now because the compression test showed its 35psi down on the 5th cylinder than the others and they will want to die soon so thats y im going for a whole bottom end. My mate brought a rb25 and took the head off for a VL show car and said i can have the bottom for 300 and its only done 60,000km i checked it and its fine.

all i need to know is because its come from a Auto and a Rwc car

i have a manual and a gts4

the 4wd system is no problem i believe?

but im not sure on the deal with the automatic? A nissan mechanic guy i know said i will need to switch the sumps around so its got my old manual sump on it but i didn't get to talk to him about any other things

info about cams and bottom ends and such would be muchlyyy appreciated ;)

Link to comment
https://www.sau.com.au/forums/topic/214924-replacing-a-bottom-end/
Share on other sites

a different cam should have nothing to do with bottom end???

an auto or manual engine should also make no difference, just change the flywheel over. But for 4WD the sump will be be different between the 2. I'm not sure if there are any other differences though. Also, i severely doubt your cars done 160,00 original kms, double it and you get a more accurate amount its probably done... "checked it and its fine" how exactly? You'd prob get more help in general questions as this isn't really an N/A specific topic.

what were the results from the compression test? You said 35psi down on cyl 5, but compared to what? 4.2L of oil is a lot for such short distance, sure it doesn't have a leaking seal as well? Does it actually blow blue smoke? If i was in your position, i'd be more inclines to just rebuild the old motor, new seals, rings and bearing, bit of a block shave (you could safely bump the CR up .5 or so for a bit more go). Car will go better than ever, and you wont have to worry about any of it again.

What are you acctually asking? How to put on a 3L bottom end?

http://www.skylinesaustralia.com/forums/RB...sions-f184.html

(3L conversion section of the forum)

http://www.skylinesaustralia.com/forums/Po...sp-t194033.html

(first page. A short rundown on how its done)

Dont bother doing cams. It will have absolutely nothing to do with the block.

Clyinder 5 - Is the PSI press 35? Or 35 PSI lower than the others? This could either mean Rings or Head gasket. Either way, the head has to come off. You could quite easily replace the block with all components for quite cheap. You could keep your block and replace and freshen it up - New bearings, rings, hone, etc. etc.

In terms of converting a 3L block to mate up to the front diff, its not that simple. You need an adaptor plate. Cheak the RB30 section of the forums to see how others have done.

If your going to take your engne apart you may aswell work it abit aswell. Again, see the NA sticky.

What are you acctually asking? How to put on a 3L bottom end?

http://www.skylinesaustralia.com/forums/RB...sions-f184.html

(3L conversion section of the forum)

http://www.skylinesaustralia.com/forums/Po...sp-t194033.html

(first page. A short rundown on how its done)

Dont bother doing cams. It will have absolutely nothing to do with the block.

Clyinder 5 - Is the PSI press 35? Or 35 PSI lower than the others? This could either mean Rings or Head gasket. Either way, the head has to come off. You could quite easily replace the block with all components for quite cheap. You could keep your block and replace and freshen it up - New bearings, rings, hone, etc. etc.

In terms of converting a 3L block to mate up to the front diff, its not that simple. You need an adaptor plate. Cheak the RB30 section of the forums to see how others have done.

If your going to take your engne apart you may aswell work it abit aswell. Again, see the NA sticky.

haha

yeh sorry guys it was a rushed topic and i wanted bed

yeh general questions may be better but i was hoping to hear it from a N/A point of view.

by the way its not the rb30 bottom i am looking for i just want to keep it a rb25.

haha, i know cams are on the top end its just im taking the engine out i wanted to change them to a better than stock part and just wanted to hear some good cams to go with if any of you know some?

yeh i talked to my friends dad

all he said was change the sump, so thats easy.

yeh the blue smoke pours out in 1st and 2nd

people behind the car blow the smoke away from there face if they cross the road behind it :blink:

a rebuild would be like building a engine back to new, but i dont think im worrying about that at the moment because its only my P's car and if i can keep it in good condition without spending a lot and get some power ill be happy with it :)

and because its a 60,000km engine my friend has sitting there and ive looked over it for scorch marks and such it looks like it wouldnt have been wound back so $300 is my bargain for me ill just change the ring and the bearing and etc because there pretty much a must my uncle was telling me.

thanks for feedback on what you could bring up ill take a look around the general parts

but advise on a style of cam would be appreciated :rolleyes:

P.S im getting the papers off my mechanic i left them there at the shop but i remember the psi from the compression test was not far off the stock psi from stock excluding the 5th cylinder.

if you can get the rb25 bottom end of your mate for 300 bucks then go for it

if the 5th cylinder is low on compression then i would most likely say that its a combination of rings and ring lands that are gone, and most likely the bore is seriously scratched

get the block of your mate, drop in new rings and bearings and put your head back on and voila - newish engine again

i went for a look at the block today at the workshop and its AMAZING CONDITION! :)

yeh the engine is just getting more and more thirsty for oil so now to do the labor ... :thumbsup:

your mates engine, was that definately a na rb25? its not a rb25det bottom end is it?

Also your gts4 rb25 block will be wider to accomindate the front diff, so im 99% sure it wont just bolt up.

I know you can go the other way, use a gts4 rb25 and put the rwd sump and it will work fine, but the normal rb25 rwd block doesnt have the holes for the front diff to bolt up.

Just worth checking into...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Well, after the full circus this week (new gearbag, 14 psi actuator on, injectors and AFM upgraded, and.....turbo repair) the diagnosis on the wastegate is in. It was broken. It was broken in a really strange way. The weld that holds the lever arm onto the wastegate flapper shaft broke. Broke completely, but broke in such a way that it could go back together in the "correct" position, or it could rearrange itself somewhere else along the fracture plane and sit with the flapper not parallel to the lever. So, who knows how and when exactly what happened? No-one will ever know. Was it broken like this the first time it spat the circlip and wedged itself deep into the dump? Or was it only broken when I tried to pry it back into place? (I didn't try that hard, but who knows?). Or did it break first? Or did it break between the first and second event of wierdness? Meh. It doesn't matter now. It is welded back together. And it is now held closed by a 14 psi actuator, so...the car has been tuned with the supporting mods (and the order of operations there is that the supporting mods and dyno needed to be able to be done first before adding boost, because it was pinging on <<14 psi with the new turbo with only a 6 psi actuator). And then tuned up a bit, and with the boost controller turned off throughout that process. So it was only running WG pressure and so only hit about 15-16 psi. The turbo is still ever so slightly lazier than might be preferred - like it is still a bit on the big side for the engine. I haven't tested it on the road properly in any way - just driven it around in traffic for a half hour or so. But it is like chalk and cheese compared to what it was. Between dyno numbers and driving feedback: It makes 100 kW at 3k rpm, which is OK, could be better. That's stock 2JZ territory, or RB20 with G series 550. It actually starts building boost from 2k, which is certainly better than it did recently (with all the WG flapper bullshit). Although it's hard to remember what it was like prior to all that - it certainly seems much, much better. And that makes sense, given the WG was probably starting to blow open at anything above about 3 psi anyway (with the 6 psi actuator). It doesn't really get to "full boost" (say 16 psi) until >>4k rpm. I am hopeful that this is a feature of the lack of boost controller keeping boost pressure off the actuator, because it was turned off for the dyno and off for the drives afterward. There's more to be found here, I'm sure. It made 230 rwkW at not a lot more than 6k and held it to over 7k, so there seems to be plenty of potential to get it up to 250-260rwkW with 18 psi or so, which would be a decent effort, considering the stock sized turbo inlet pipework and AFM, and the return flow cooler. According to Tao, those things should definitely put a bit of a limit on it by that sort of number. I must stress that I have not opened the throttle 100% on the road yet - well, at least not 100% and allowed it to wind all the way up. It'll have to wait until some reasonable opportunity. I'm quite looking forward to that - it feels massively better than it has in a loooong time. It's back to its old self, plus about 20% extra powers over the best it ever did before. I'm going to get the boost controller set up to maximise spool and settle at no more than ~17 psi (for now) and then go back on the dyno to see what we can squeeze out of it. There is other interesting news too. I put together a replacement tube to fit the R35 AFM in the stock location. This is the first time the tuner has worked with one, because anyone else he has tuned for has gone from Z32 territory to aftermarket ECU. No-one has ever wanted to stay Nistuned and do what I've done. Anyway, his feedback is that the R35 AFM is super super super responsive. Tiny little changes in throttle position or load turn up immediately as a cell change on the maps. Way, way more responsive than any of the old skool AFMs. Makes it quite diffifult to tune as you have to stay right on top of that so you don't wander off the cell you wanted to tune. But it certainly seems to help with real world throttle response. That's hard to separate from all the other things that changed, but the "pedal feel" is certainly crisp.
    • I'm a bit confused by this post, so I'll address the bit I understand lol.  Use an air compressor and blow away the guide coat sanding residue. All the better if you have a moisture trap for your compressor. You'd want to do this a few times as you sand the area, you wouldn't for example sand the entire area till you think its perfect and then 'confirm' that is it by blowing away the guide coat residue.  Sand the area, blow away the guide coat residue, inspect the panel, back to sanding... rinse and repeat. 
    • The detail level is about right for the money they charge for the full kit... AU$21.00 each issue, 110 issues for a total of $2,300 (I mentioned $2.2K in the first post when the exchange rate was better). $20/week is doable... 馃槓
    • If planning on joining us for the day(s) please indicate by filling in this form. https://forms.gle/Ma8Nn4DzYVA8uDHg7
    • You put the driver's seat on the wrong side! Incredible detail on all of this. It looks like you could learn a lot about the car just from assembling the kit.
  • Create New...