rb20 rebuild budget

[CEF11E]

I would like to know how much i should budget to rebuild my rb20.

there is nothing wrong with it apart from a few ks on it.

I just want to do a propper rebuild and need to know what to do

I guess get the block chemically cleaned and honed machining journals? how much?

have pistons balanced do i need new pistons? how much?

get the rods balanced?

rod bolts?

bearings, rings, gaskets, valves, springs

having never undertaken a rebuild i dont know how much to budget.

I want the bottom ent to cope with 210-220 rwkw so nothing to special

can anyone recommend a place in sydney that will do the lot for me? ie drop off motor pick up rebuilt later?

can you save cash doing some work yourself?

thanks

[cameron]

You carnt machine it your self but you can assemble it your self .

You need the right tention settings for rods bolts and heads bolts and other things. Just be careful putting rings on pistons beceause if they break you have to buy whole new set of pistons because you carnt get them seperate - That i know of.

I'd go forged pistons to keep your enigne stronger so it lasts in the long run.

Jun

[meggala]

ceffie that motor was pretty good 12 months ago it had the head off and it was checked only had aroudn 70000 klms then and the car had 100 and something dont spend the cash till it blows if you want to run up to 200- 220 bolt in an rb 25 there are alot of good reasons for this namely the injectors will handel that much power its torquier etc.

the reason it has a little bit less power than the other cefs is the motor is from an r32 not a cefiro ceffies have bigger cams

yes I'm pretty sure it was my old black ceff

cheers

meggala

[frasha6]

G'day fellas, I'm pretty new to this so bare with me. I wish I found this forum earlier. I recently had an ordinary experience with an engine rebuild. I had my r32 gtst for about 2 years when I blew the engine while in the gong. I live in neutral bay so I got the car towed to a workshop in brookvale that I had the car serviced at previously. They said they did rebuilds so I got a quote and they got started. It was supposed to have Arias forged pistons, metal head gasket, HKS cam gears, Tomei cams, the usual head work/machining etc.

Anyway, the basics are, I know very little about the mechanical side, I don't work on cars myself, but I had the money to have some fun with it. I handed over a Chq for half of what I intended to spend, six months later, the knob hadn't even started ordering parts for the car. I was losing it. I ended up getting the car back, engine rebuilt, yet without cams, cam gears, metal head gasket. Basically headwork and pistons. The guy is a complete rort. I'm currently compiling a court case.

Sorry about the long winded whinge, just be careful who you trust.

[CEF11E]

ceffie that motor was pretty good 12 months ago it had the head off and it was checked only had aroudn 70000 klms then and the car had 100 and something dont spend the cash till it blows if you want to run up to 200- 220 bolt in an rb 25 there are alot of good reasons for this namely  the injectors will handel that much power its torquier etc.

the reason it has a little bit less power than the other cefs is the motor is from an r32 not a cefiro ceffies have bigger cams

 

yes I'm pretty sure it was my old black ceff

cheers

meggala

Hi Megalla yep its your old car i just didnt want to bug you too much i didnt want to ask you every little detail of the car as its not your problem anymore.

Yeah the engine still seems fine except when i am maximum throttle and rev it to 7k then change gears and give it gas it pings just a little untill the revs get back up over 5k and then its fine.

I have had the A/F ratios checked and they are fine.

mods i have done since having the car

FMIC 600 x 300 + waterspray kit

new injectors just cleaned and flowtested

RB25 turb slightly hiflowed

turb back exhaust 3" "with cat thistime" hehe!

oil catch can

custom air intake/box

bigger fuel pump

Did u do any work on the bottom end Steve? or did you just replace the burnt valve?

Cheers mate

what r u driving now?

[Roy]

If you are after 200-210rwks then all things being equal the engine will handle that no prob.

If it dies and you find you werent happy with that power then just throw in an RB25, but i wouldnt go re-building the RB20 especially if its alive and running:cheers:

If you are keen to rebuild the RB20 the two thing I would do is use 81-82mm pistons to bump up the capacity a little and when slecting the pistons id try and lift compression a little to around 8.8:1. Then i would clean up the ports and combustion chambers and throw in a set of cams to try and get the head flowing a bit better. So thats 3 things, pistons, cams and headwork...without the cams and headwork the thing will be tough as nails but never really make any good numbers:(

Id stick with std rods, std crank and enjoy what would be a pretty surprising and very tough engine....sadly a std RB25 will more likely make more power easier, and you would have to be looking at over 250rwkws before the RB20 with internals could be seen as beign more reliable then a std RB25 with a high flow turbo or HKS2535 etc

Basically if you are opening up an RB20 you have to go stupid to make it worth it, otherwise just keep throwing std engines at it...my 2c

[dangerous_daveo]

The RB25 conversion would add up pretty quickly tho if you cant do that much yourself...

But out of interest (sorry to highjack) but what would we call 'going stupid' on an RB20?

[Roy]

Ok my dream RB20 (its a dream engine as it makes no sense in the real world where you need bang for dollar)

- 82mm forged pistons.

- RB26 crank

- Aftermarket GTR rods, Argo etc etc

- N1 GTR water and oil pumps

- 270 - 9.2mm cams and springs

- Plenty of headwork

- Extrude honed inlet manifold with larger throttle body

- Tomei Solid lifter kit

- HPC coated valves and combustion chamber

- HKS 3037S or maybe a T04Z

- 650cc injectors

- twin palte clutch

- RB25 5-spd

The thing would rev its t1ts off, with the same stroke as an RB26 but with smaller diam (ie lighter pistons) it would easily rev as hard as a tweaked RB26 , imagine 9,000rpm and banshee sound from the wastegate.

With the 3037S it would be reasonalby responsive at 2.4L and 8.8:1 compression. Id assume it woudl make 320-350rwkws at between 1.4-1.8bar

With the T04Z it would likely make over 350rwkws.. hell i even thought how would the RB20 block go with a HKS 2.8L crank!!!! Throw somthing like the HKS T04Z on an R31 GTSR low mount manifold and ppl wouldnt expect anything from the stock looking (ok maybe not sounding:)) RB20, complete with original RB20 engine number,

[dangerous_daveo]

Ahhh haaa... And cost of that? $20k+???

[DRFT32]

going out to 82 mm bore is very oversize....that must be getting close to the water jackets ?? not such a great idea on turbo engines ????

has any taken the bore out this far ???

i just got 0.5mm oversize done with Arias Pistons so prices were as follows

Bore Block - $180

Line Hone - $240

Balance of Crank,rods and pistons - $280

Deck Block $65

(New Pistons had a range of 2 grams now an even 297.5g)

hope that helps

[Roy]

I dunno, Most Jap Kits i have seen are 82mm pistons, some are 81, Testarossa make a kit that uses 83mm!!!! pistons. Id be inclinced to stick with 81mm myself, but if Tomei say 82, then i guess your hoping they know what they are on about.

[DRFT32]

is any one using Arias pistons in their RB20

did they notice any difference or have any problems???

Yeah i guess if they say 82 then i guess can't be too bad....but that still is alot.

[Cubes]

It will cost an extra 1k or so but I would seriously look at building up an RB25 instead.

Take one for a spin and you will soon realise why the old saying of 'There's no replacement for displacement' is so so true.

The RB25 is a simple drop it in exercise providing you go with the RB25DE NA head.

I went for the RB30 bottom end rebuild that required a few little mods like engine mounts, front pipe and turbo oil/water lines. Nothing major though. The mods all up cost an extra $150. That was $70 for the engine mounts and $80 for the dump pipe.

The other mods (slight bending of the oil/water lines) can be done by your self.

I really am so so glad I went with the larger motor and didn't waste money on rebuilding a rb20. With the turbo's wastegate disabled (wired fully open) it made 133rwkw at 5000rpm (where power started to flatten out & because it is a fairly fresh motor it wasn't rev'd any more) with an AFR of 11:1 and ignition timing of 15deg, stock turbo & stock RB20DET ECU.

Even with the wastegate wired fully open it still made 6psi of boost above 4000rpm.

Below 3500rpm there is zero boost.