200zr RB30/26 build

[technonerd]

 

Current plan is to build a RB30/26 in my 1987 200zr. First major project car. I also have a 1983 280zx 2+2, I might have a thing for 2+2. 200zr came in 2+0/2+2 and the rare slicktop configuration.

 

I had dropped some valves in #6 cylinder and it punched a hole through my piston and trashed the head. Ill have a nice desk paper weight! The NICS redtop that came from factory isnt exactly the best RB20 out there so I guess time to start from scratch. But carnage pics,

 

  

 

Current plan is to overbuild a little bit and start fresh with brand new parts. 1, I know how many miles are on that part 2, I know history and how hard itll will/was be beaten on. At the time of writing there is only ~8 200zr's state side and depending on which internet source you find. Roughly 5000 total were made. So a wee bit special, so lets build this thing correctly and for the long term. I want to drive the piss out of it. Streetable and low end response is what im mostly looking/building for. I will mostly be doing autocross, track days and some 1/4 mile passes. Current goal is 500hp at the crank.

 

Current parts wish list so far,

 

PRP RB30 prepped block

PRP RB30 crankshaft

PRP oil pump

• Gears cryo treated and WPC treated

PRP trigger kit

Tomei complete stage 2 RB26DET head

• 1mm oversized valves

• Ti valve retainers

• CC volume 67cc

• procam camshaft 260/10.25

IRP Pistons Silver

IRP Conrods Silver

ACL bearings

Nismo super coppermix twin disc clutch

Garrett - GTX3584RS with 1.06 twinscroll

Greddy style intake

6boost top mount exhaust

Nismo 740cc injectors

OS Giken gears

• OS Giken Reinforced Center Plate

• gears 1-3

• Reinforced Input Shaft

• Z31/32 FS5R30A with RB25 bellhousing swap? 200zr came with FS5W71C still unsure on the swap details for this

• OEM syncros cryo treated and WPC treated

OEM Clutch LSD with 4.375 final drive, needs rebuild or nismo LSD route.

Fueltech standalone

 

With the twinscroll setup I can afford to bump up to a 1.06 on the hot side versus using .83?

[Duncan]

RB30 blocks are a great way to go, but before you get too far are you sure there will be clearance at the front of the motor as the block is about 30mm higher?

Fitting RB30 in R chassis is pretty well understood but I've not seen one in a Z chassis...

[technonerd]

On 11/16/2021 at 7:39 PM, Duncan said:

RB30 blocks are a great way to go, but before you get too far are you sure there will be clearance at the front of the motor as the block is about 30mm higher?

Fitting RB30 in R chassis is pretty well understood but I've not seen one in a Z chassis...

The 200zr came with a top mount intercooler. With the iconic slightly offset inlet on the hood sitting right on the intercooler. Not like other Z31's with the opening being all the way on the right hand side of the hood. Some rough measurements everything is apart at the moment. From the top of my valve cover to the bottom portion of the weatherstripping for the hood puts me at about 41/2 inches (115mm) lets be even more conservative and say I have 100mm of wiggle room to play with. Now If we go from the RB20 block to same weatherstripping point I get conservative 12 in (300mm). RB30 block is 38mm taller, lets go with 40mm + 10mm for valve drains. I have about 50mm of wiggle room on the backside of the block. What that will equate to on the front of block/hood clearance wise im unsure of.  But cutting a hole for the cam gears because racecar things, id be ok with. So at least according to my napkin math while being super conservative it'll fit at least on the back of the block lol. Hard to say if the front will, probably also means I can't run a top mount turbo. Hard to theorize if it'll fit when no one has done it and I don't have the parts in front of me. Some one has todo the experimenting and document, document, document. Like any good IT admin

I am going to rig up a simple 90 degree bracket with some wood.  Are the RB26 and RB20 head the same height wise?

As for seeing RB30s in s Z I don't see any off hand, need more google/archive.org digging.

Anybody have any more info on this Z31? Owner? https://www.facebook.com/upgarage/videos/247971442585532/

[GTSBoy]

Almost certainly won't fit at the front Z31 has very low height at the front of the engine bay. RB30/2Xs already don't fit in R32s without chopping stuff (bonnet ribs) where the timing cover hits.

I don't have any problem with you wanting to put a 3L in there....I just think that a V6 would likely be the sensible choice, as horrible as that is to have to say.

But, if you do go RB30, don't f**k about with RB26 head. Let some other Yank pay GTR tax for that. Use the better RB25 Neo head. Internet points for RB26 are nothing compared to better actual performance.

[Rusty Nuts]

On 11/17/2021 at 9:39 AM, GTSBoy said:

Use the better RB25 Neo head. Internet points for RB26 are nothing compared to better actual performance.

Good advice. Take it and run its free.

[khezz]

Sounds like an awesome project. Good luck with it mate.

[technonerd]

It's been awhile but my PRP RB30 finally arrived. Ran into a slight problem with the prp brace being setup for 4wd and the 200zr oil pan requiring extra set of bolts to fit. Currently talking with herman to sort that out. It was also recommended  to run a larger pan, so I might have to scrap the 200zr rear mount oil pan all together, modify it, or find a rear mount sump that will fit. The 200zr oil pan seems to be a modified patrol pan just cut shorter.

In the chaos of ordering parts I forgot a head gasket but ended up going with a 1.6mm athena. Ordered a boost doc heater delete kit but want to modify it to keep a creature comfort aka heat. It was mostly to help clean up

My current todo list is to send my tomei head out to get the head bolts holes enlarged to 1/2" , find an oil pan that will fit and wait for boost doc parts to arrive.

[Javier_Z31]

Looking really good. I’m basically doing the same engine swap into my Z31 but I won’t use the PRP brace.  
  The Nissan Patrol oil pan needs to be cut and modified to clear the 200ZR rack and pinion. 

[morboost]

https://www.cxracing.com/oil-pan-nissan-300zx-z32/OP-RB25-300ZX

this is a rear mount rb oil pan

[Javier_Z31]

I’m just going to leave this here . 
https://upgarageusa.com/products/jhk-rear-sump-rb-cast-oil-pan?variant=39899848015907

[technonerd]

I ended up going with the cxracing pan despite its terrible reputation, and I had looked at the upgrage one in my search for a rear mount one.

Running into dont have the correct part or A part problem, its gunna be a long, frustrating, learning on the fly type build. Ill eventually will get it done hopefully this summer. Lots of waiting for parts.

Tried to use my old head dowels off the old RB20 but that didnt work no matter how much I tried. But good thing PRP makes 1/2in head dowels. Got boost doc splash guards installed. I just used the old bolts from the 200zr valve setup no need to drill and tap holes despite the rear most needing to be tapped. Also picked up the boost doc heater delete to help clean things up but plan on getting an T fitting for the rear water port on the block so I can still have heat. Creature comfort!!! And last pic is just a test fit for the time being, need to loctite the nuts on studs for the splash guard