Ive decided to build myself an RB engine for my vl from the block up, basically just mixing and matching components like an RB25DE head etc. But while im on the block, how much can i get it bored out to? Im not worried about the price of getting custom pistons made up, but has anyone heard of the safest maximum amount to bore out the block? Ive heard its been done so the final capacity is 3.1L, can u go larger? Are there aftermarket stroker kits out there for the RB30 to help?

Best way mate bore it out 20thou only, unless its been rebuilt before. I hear there are stroker kits available but only if you got $8000 or something...

$8000?!!! Forget that, I aint THAT rich (actually, im quiet the opposite atm :? ) If thats what u need to get for more capacity, forget it. What do u get from getting it bored 20 thou tho (ie. what does that mean?). Ive heard that alot of ppl get it done, but not what it does for u. Will u need new pistons for that 20 thou? I cant use the vl turbo pistons as they'll throw off my compression ratio too much (the rb25 head will give me a good overall compression me thinks)

getting it bored means they will machine it out.. ie. 20 thousandths over size.. and yeah i am nearly positive that u will need new pistons to suit..

..the bores get worn from years of use and so usually when you rebuild after so many km's the bores will need to be enlarged slightly to get them back into a perfect cylinder shape. Usually 10 or 20 thou over standard bore size will get rid of all the imperfections. Boring out the block is not usually done just to increase capacity, it increases capacity by so little its hardly worth it, and the more you bore the block out the thinner your water jackets get and the weaker your block gets - so you need to be careful with big HP engines. Is it going to be turbo? I'd probably use RB30E pistons - the RB25DE head has larger combustion chambers than the RB30 head and so will lower your compression ratio - RB30E pistons should bump it back up to around 8.3:1 or there is guy at the moment building a n/a RB30DE using the RB25 head and RB25 pistons and slight deck shave to get 10.5:1 compression. 8.3:1 would be ok for a turbo engine.

Quote: $8000?!!! Forget that, I aint THAT rich (actually, im quiet the opposite atm ) Don't wanna spoil it for you champ, but to do what your Topic title suggest's will require you to be rich.

nah. cause im building up a whole new engine to be dropped in my vl later, i can do it as slow as i want, so money really isnt an issue (power is limited only by how long im willing to wait) Yeah its gonna be turbo'd, and yeah i was worrying about compression ratio cause i want to get everything right first time around. If I go twin turbo, can i use smaller turbos to save on money?

You might need to talk to a few specialist engine builder's regarding cause from what i've read in your first post your unsure whether you want to make power with rev's (Twin Cam Head) or other (3.1 litre capacity).

Quote: If I go twin turbo, can i use smaller turbos to save on money? building a "monster twin cam engine" u cant really be asking stuff like that... like others have said.. "speed costs money, how fast do u want to go". maybe u should sit down and figure out what u really want from ur car, and what u have to do to get there.

ViperVL - If you go twin turbo then you wont be saving yourself money because you have to make up 2 of everything turbo related unless you are getting alot of stuff cheap/free its not a realisticly viable option for someone who is "on a budget".

he wants twin turbos, twin cams, big capacitiy, lots of revs, heaps of power and low cost. dont we all? you said $8000 is too much but then you say money isnt an issue...

Quote: If I go twin turbo, can i use smaller turbos to save on money? There's no such thing as saving money with something like this, sorry to say champ.

Quote: he wants twin turbos, twin cams, big capacitiy, lots of revs, heaps of power and low cost. dont we all? i do. Some original photos have not been recovered yet.

only bore RB30 blocks as small as possible . theya re prone to sliting bores under high boost

cripes i guess ur right, i am all over the place with what i want... I want to go twim cam cause my current engine in a n/a. To turbo it, id need to change the compression ratio to be able to get any real boost, and even though this can be done for alot cheaper than a twin cam head, a twim cam head also has the added bonus of being able to breathe alot easier, and they arent so common (me likes that part). anyway thx all... i think i had better go sit down and have a serious rethink.

I went for a Nissan Rb30DE conversion because I had a good honest hard think about what I wanted from my car and what I could afford,I didn't want anything which put out much more than 200 kw,I am not rich,I wanted a twin cam engine for something different and for the fact that improvements have been made on the later RB engines,I had always wanted a turbo car but the engine needed a TO4B or custom TO4 turbo (expensive) or at least twin T25 turbochargers and the power it would generate was way beyond what I wanted (around 400 - 500 BHP),I calculated a bare minimum of 225 kw to be generated at low boost just borderline to the turbochargers minimum efficiency, but for the added expense that money could be better spent on the single cam turbo engine or as I have done (mostly) built an RB30DE non turbo engine. The RB30DE motor can be tuned to put out at least 225 kw with aftermaket engine management and 6 throttle bodies,but all of that is above my means so I am using an RB25DE management which limits its potential to 187 kw with the standard single throttle body. I would like a very powerful car but my means to afford to run a car like that isn't enough so I went for a more realistic power figure,I had been in a 200 Kw car and I was happy with how it performed,so I went for around the 200 KW mark. Other factors included the fact I would have to buy a new gearbox (MX7) and I would've rebuilt it to handle the power

200flywheelkw's, youll get that with exhaust, boost and a cooler. rwkw's youll need a bit more work but you certainly wont need to go twin anything, your wasting your money if you want stuff all power anyway.

when it comes to boring you cylinders, the vl's go in three stages. Stage 1 - 0.02mm oversize Stage 2 - 0.5mm oversize Stage 3 - 1mm oversize When referring to these engines, nobody actually talks in the imperial measurement. It's all metric... don't ask me why. I'm having my block taken out to 1mm oversize (which is the rough equivelant of 50thou oversize) and filling the cylinders with Wiseco forged pistons. Should be good Cheers, Nick

Simple plan, but like everyone says to everyone else. BIG HP=BIG $$$. First rebuild bottom end, with forged pistons and rods and standard shotpeened, nitrided or cryoed and knife edged crank. Make sure it is properly balanced. This will cost anything from $3000 up. I'd guess $4000 for a good job. Then add rb25 twincam head. This will cost @ $2000. I'd also give the head a port and polish and add better cams and springs. This will cost @ $2500. Then add single garrett gt30 turbo @ $2500. You'll then need a custom exhaust manifold and external wastegate @ $2000. Then get yourself a 600 x 300 x 75 min size intercooler and get piping made up. This will cost $1600 . Then get yourself a computer to run it and all the fuel system as well. Costs for this will start @ $3000. Then get a twinplate clutch @ $2000. Then you'll need a good lsd diff. I don't know, say about $1500. So all up it will cost a tad over $20000. But feel free to correct me. P.S. If you can do some of the work and find seconhand parts or better priced parts you'll save a pretty penny too.

Most workshop's give some form of discount if you come in and get a complete package done with them all at once. For example, to purchase all the part's individually, then getting them fitted separate could cost say $22k+, but doing it all at once they could do it for $20k.