Jump to content
SAU Community

Recommended Posts

hi, building up an rb30 in my back shed, and the crankshaft has been worn about ten thou by both oil seals, just wondering if people have used a sleeve or just put it back as is and if so did it leak, idealy i would like to put a sleeve on but this would involve machining the crank, i'm trying to keep it cheap as possible, as i've blown enough cash on recent cars as it is. also one of the cylinders has a small score in it, but below what seems to be the travel of the piston, (which i did of course removing the piston, damn!), would i need to get the block bored now or will it be ok?

cheers for any help,

troy.

Link to comment
https://www.sau.com.au/forums/topic/241971-crank-oil-seal-diameter-damage/
Share on other sites

also does anyone have the stock crank diameter tolerances, aswell as the cylinder bore diameter tolerances, just so i can check the block and crank before i put it back together. how much power can the stock rods handle, sorry i know its been covered but i can't find it.

600hp, if the crank is badly scored, then you can fit a "speedy sleeve" without the need for any machining

ok, so the speedy sleeves have been used sucessfully by people building these engines? so i take it upgrading the rods to forgies wouldn't be worth doin for 350 kw atw car, just get the stockos treated

I would definately upgrade the rods for 350rwkw, thats about the safe limit of the stockers. By the time you fit ARP rod bolts, and get them sidepolished and shotpeened, big and little ends resized there isnt much difference in the cost.

the cost difference between a 25 and 26 head

is around 600?

but 26 head goes straight on

25 head u need to weld/mod/tap

26 also has a forward facing plenum

26 has solid lifters

what car is it going in?

the cost difference between a 25 and 26 head

is around 600?

but 26 head goes straight on

25 head u need to weld/mod/tap

26 also has a forward facing plenum

26 has solid lifters

what car is it going in?

the engine will be goin in my r33gtst, but i need the car to be running to get to work, so i'll have to purchase a head for the rb30, got qouted 350 for a 25det and 1200 for a 26, i know that the 25det has problems with the valve float under high power, but will chucking a set of 26 valve springs in it fix the problem? just wondering what peoples opions are about the two heads side by side, waying up the cost difference. for those that have welded the 25det head, what was the preferred method, the block is cast iron so just wondering what people have used, eg mig with cast iron wire etc. i'm trying to do as much as i can, with no engine building experience, but i'm a fitter and turner so i'm able to drill, tap, modify etc. i wouldn't have even tryed without these threads.

To mod the rb25 head, i drill and tap the oil gallery and fit a m8 grubscrew in there, then get the head welded where the water gallery is close to the edge of the head gasket, i had a head welded and surface ground for $100.

ok, well that sounds pretty basic, 100bucks aint to bad either, looks like i'll probably be goin the 25 with 26 valve springs, i noticed that alot of people are choosing the 25de (na) heads over the 25 det heads, whats the reason 4 this, please excuse my ignorance but couldn't find anything

i know its a long shot but does anyone have the approximate dimensions of the jun crank collar, gunna make one, can't see how they can jusify the 200 odd bucks they sell them for. any help would be greatly appreciated just after some rough sizes.

Edited by roy33

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

    • Cheers. Skyline is back on the menu, can’t get rid of it. It’s like a child you don’t want, or herpes 
    • I got back to Japan in January and was keen to get back on track as quickly as possible. Europe is god-awful for track accessibility (by comparison), so I picked up a first-gen GT86 in December just to have something I could jump into right away. The Skyline came over in a container this time and landed in early January. It was a bit battered after Europe, though—I refused to do anything beyond essential upkeep while it was over there. The clutch master cylinder gave out, and so did the power steering. I didn’t even bother changing the oil; it was the same stuff that went in just before I left Japan the first time. Naughty. Power steering parts would’ve cost double with shipping and taxes, so knowing I’d be heading back to Japan, I just postponed it and powered through the arm workout. It took a solid three months to get the car back on the road. Registration was a nightmare this time around. There were a bunch of BS fees to navigate, and sourcing parts was a headache. I needed stock seats for shaken, mistakenly blew 34k JPY on some ENR34 seats—which, of course, didn’t fit—then ended up having the car’s technical sheet amended to register it as a two-seater with the Brides. Then there’s the GT86. Amazing car. Does everything I want it to do. Parts are cheap, easy to find, and I don’t care what anyone says—it’s super rewarding to drive. I’ve done a few basic mods: diff ratio, coilovers, discs, pads, seat, etc. It already had a new exhaust manifold and the 180kph limiter removed, so I assume it’s running some kind of map. I’ve just been thrashing it at the track non-stop—mostly Fuji Speedway now, since I need something with higher speed after all that autobahn time. The wheels on the R34 always pissed me off—too big, and it was a nightmare getting tires to fit properly under the arches. So I threw in the towel and bought something that fits better. Looks way cleaner too (at least to me)—less hotboy, less attention-seeking. Still an R34, though. Now for future plans. There are a few things still outstanding with the car. First up, the rear subframe needs an overhaul—that’s priority one. Next, I need to figure out an engine rebuild plan. No timeline yet, but I want to keep it economical—not cutting corners, just not throwing tens of thousands at a mechanic I can barely communicate with. And finally, paint. Plus a bit of tidying up here and there.  
    • Nope, needed to clearance under the bar a little with a heat gun, a 1/2" extension as the "clearancer", and big hammer, I was aware of this from the onset, they fit a 2.0 with this intake no problems, but, the 2.5 is around 15mm taller than a 2.0, so "clearancing" was required  It "just" touched when test fitting, now, I have about 10mm of clearance  You cannot see where it was done, and so far, there's no contact when giving it the beans Happy days
    • It's been a while since I've updated this thread. The last year (and some) has been very hectic. In the second-half of 2024 I took the R34 on a trip through Germany, Italy, France and Switzerland - it was f*cking great. I got a little annoyed with the attention the car was getting around Europe and really didn't drive it that much. I could barely work on the car since I was living in an inner-city apartment (with underground parking). During the trip, the car lost power steering in France - split hose - and I ended up driving around 4,000kms with no power steering.  There were a few Nurburgring trips here and there, but in total the R34 amassed just shy of 7,000kms on European roads. Long story short, I broke up with the reason I was transferred to Europe for and requested to be moved back to Japan. The E90, loved it. It was a sunk cost of around EUR 10,000 and I sold it to a friend for EUR 1,500 just to get rid of it quickly. Trust me, moving countries f*cking sucks and I could not be bothered to be as methodical as I was the first time around.
×
×
  • Create New...