adams 02rs

Thinking about building a spare rb20 I have, and I'm still debating what route I wanna go with the rb. Any feedback on rb20 builds would be appreciated, would like to see close to 600hp reliably.

Oil pump setups? Oil pump gears? Crank collar?
Springs, retainers, shims, cams, etc
Compression ratio's and bore size/ piston size
Or should i stroke it and what would be a ideal setup to stroke it?
Or keep it a rb20? And go a little over?

I'm pretty new to rb's, don't flame my newbiness.

Thank you.

wowzers9930

Sell it and buy an rb25, if you wanna make anything over 400whp the rb20 will be a laggy turd. Just sayin

adams 02rs

and exactly how will it be a laggy turd?
how will it be more difficult then getting a sr20 to 400whp? wich is a 2000cc engine as well. idk, thats why i ask?

s14-rb20det

My RB20 have 500WHP, and is laggy full boost on 4200rpm 23psi on PT6262 AR70 cold AR84 hot.

adams 02rs

Its not the size of the boat bro its the motion in the ocean, And 4200 at full boost doesn't sound too bad on a rb with a 6262.

What I'm looking for is build specs, and suggestions regarding THE BUILD ITSELF. What would make it more quicker rev/rev faster(responsive), and be a solid power plant. (if that makes sense). Most importantly I don't give too shits if you tell me too buy a rb25,thank you tho for your opinion. I want to know info about a rb20 ,not a 25. Please refrain from rb25 talk.

I'm also always searching this forum and others as well. Haven't found a whole lot. That is why I resorted to posting the thread. Thank you again zilvians, feedback appreciated.

Sforteen

Crank needs a collar, N1 pump will probably be fine, as long as crank is collar'd

If i was in your shoes id use the RB26 crank (R33-up dont need a collar) for the extra displacement, Keep the bore size small, increasing bore takes away the rebuildability for a very small increase/gain in displacement.

Get some springs and have the head ported up a little bit and you should have a little monster on your hands.

adams 02rs

What would I need to do in order for the rb26 crank to fit, any sort of machining or work to the block? Thank you for the info I appreciate it.

What would be a good compression ratio for the pistons.. I want something to compensate for the boost yet still have some what of a good (fast) response??

Any advice on cams...lifts, durations?
Any one??? I Need help with this. Freaking search engines aren't really on my good side, can't find anything regarding actual build specs. Come on I want a fire breathing mini monster!

adams 02rs

What would I need to do in order for the rb26 crank to fit, any sort of machining or work to the block? Thank you for the info I appreciate it.

i know the strokes are different between the two, so would i need rods as well? and can i keep my cylinder walls at 79mm or would i have to bore?

NismoRich

if i remember correctly, you might have to clearance a little on the bottom of the cylinders to clear the crankshaft counterweights. i would use an R33 crank and save the hassle of having a collar installed on an R32 crank. as far as pistons and compression ratio's, i would have a custom set made and bump it up to 9 or 9.5:1. that will help with the lag and still be safe with a good tune. depending on what size turbo you decide to go with would help decide on what set of cams to run. all this would be useless though without a good engine management and tune

adams 02rs

I will be running a nistune, and hope fully a gt3071r or a holset hy35 still looking for good alternative's. The next concern is can I keep my stock bore? And would I need rb26 rods for the stroke to work with my pistons or can I keep my stock rod/ stroke length?

NismoRich

yes, rb26 rods also. and since you will need custom pistons (wrist pin hole will need to be higher on the piston), you might as well go slightly over on the bore to get around 2.3L or 2.4L's out of it.

Yellow4g63

R33 and R32 still have the crank problem with the oil pump drive. My friend has also seen it on the Neo RB25DET too which we thought for sure they would have fixed.

__________________

95 240sx RB20 415whp
91 Nx2000 VVL yo

redline racer510

Get a rb25, swap in forged pistons rods = Done

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WARNING: User has a low tolerance for stupidity. Post at your own risk.

wowzers9930

All of your turbo choices are fail for 600hp btw, you either need a gt35r or hx40 to get 600hp and on a rb20 you better have a built head to compensate with all that lag. You need to do more research.

adams 02rs

I have done plenty research, and i still continue to do so. I know I have to build the head to compensate for the lag. I'm not sure of what route I wanna go with my build yet. Just need suggestions. I will be definitely building the head and block for reliable power. I am just trying to find out what you guys have to say about specs. Thanks.


I'm currently trying to find a rb25 or 26 crank if any one has one?

Kingtal0n

dont even want to touch this. Do not build an RB20 unless you are rich.

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

adams 02rs

Why do you say that?

Kingtal0n

Lets just pretend the engine was still being produced and parts are easy to find, and cheap. Lets also pretend that it is "easy" to pull in and out of a 240sx.


It would still be a bad idea to build one because,

A. Its still a 2.0L engine with 150% of the potential for wear and tear related failures compared to a 2.0L 4-cylinder
B. You are 150% as likely to make a mistake during assembly when compared to a 2.0L 4-cylinder
C. Re-sale of parts (part out components) is more difficult because of reduced buyer base
D. There is not a single positive benefit over a 4-cylinder 2.0L engine, except for whatever the difference in rotating mass and firing order does for the "feel" and "sound" of the vehicle. In fact it probably weighs more and is more cumbersome in the engine bay, making maintenance more difficult and harming your power/weight ratio.

E. I should not need to continue but I can come up with E F G H I if you like.

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

Kingtal0n

nonsense. "built head" in this context refers to effects that improve volumetric efficiency for higher engine rotation speeds where compared to stock, and all of those modifications will increase turbocharger "lag" on all engines in that context.

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

adams 02rs

So I'm basically wasting my time with this rb20? What would you recommend to do, also how does building your head improve volumetric efficiency? I would I assume larger components would be required?? Also why does it increase turbo lag? Thanks talon, appreciate it man.

ultimateforce

RB20s are great if you want to go the scrap yard and have enough money for lunch after.

__________________
Assistant Fabrication Manager / Welder at Raw Brokerage

wowzers9930

Kingtal0n, I said that not because it will help it spool but you can have a torque curve that your not only able to use for for 2k rpm. Before you jump to conclusions about why I said what.

wowzers9930

Also, I agree with King. Dont build an rb20 unless your rich and even then its a dumb idea due to displacement when there is much better options of the same platform.

adams 02rs

Thanks. Appreciate that.

Kingtal0n

bigger ports mean lower port velocities during higher vacuum situations (low throttle position), which makes the engine respond more slowly whether turbo or N/A giving it a "laggy" feeling. You also lose some of the benefits of exhaust gas scavenging and helmholtz. Exhaust reversion and low port velocities contribute to a slower "spool".

__________________
5.3/4l80e/turbo 240sx playthrough:
https://tinyurl.com/turbo240

Sforteen

A. making simular power is less stressful on a 6 cylinder due to it being spread out over 6 cylinders..

B. So an ls1 probably cant even be built it has 8 holes!!

C. Rb20 parts still get bought up.. nobody builds something based on its later resale attributes anyway..

D. Benifits?? There cheap, its an inline 6 there easy to work on. Maybe he wants an rb20? They sound good. Benifits are up to the owner..

Most engines people swap into s chassis arent made anymore?? Whats your point?
Pulling an rb out of a 240 is by no means difficult.. it maybe for you because your from Flordia..

Every point you made is retarded.. please stay in flordia with the rest of your peeps.

ultimateforce

I'm from Florida and I know both how to use the shift key and the difference between you're and your.

__________________
Assistant Fabrication Manager / Welder at Raw Brokerage

genericforumname

At least we know how to spell the name of the state we're from, guess other states don't seem so great by comparison anymore eh?

to OP I'll say this, I've never understood why people bought rb20's, but since you already have one it's a bit different. On one hand you could sell it and get a few hundred dollars to start on something else. OR, you could spend (probably) a few thousand getting it to the level you want it at. Personally I would sell it and build something else but you could also end up with a truly crazy rb20 and end up building something a bit different.

Yellow4g63

Fixed it for you. I'd say start with bolt on parts and see where you get from that point. Bigger injectors, turbo, meth kit, fmic and a tune. If you feel like you need more and want to jump down the rabbit hole go straight to the RB26 and reuse your current harness and computer. Change your tune to match the motor and call it a day.

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95 240sx RB20 415whp
91 Nx2000 VVL yo

Yellow4g63

forgot to give you this page. RB20 rods and piston combo
http://www.spoolimports.com/spool-co...piston-package

RB24 rods and pistons: you have to email them for that one.
http://www.spoolimports.com/spool-co...piston-package

__________________

95 240sx RB20 415whp
91 Nx2000 VVL yo