Jump to content


help regarding RB20 concept!


Recommended Posts


i've been considering the RB swap for sometime...

i was told by a decently reliable source that the 200zr (z31 300zx) rb20det actually bolts straight onto the 260z....

as opposed to the R32 skyline models which need modified mounts

can someone confirm or othewise this!? as i have the oportunity to buy one in hte next few days!

Thanks, Charles

Link to comment
Share on other sites

Thats a nice and talked about idea. and something i wouldn't mind doing at some point!

BUT, my question was in regard to mounting, and i have since had confirmed that the 200zr engine mounts will mount an RB series engine perfectly.(thankyou stony's website:))

Thanks for your time!

Link to comment
Share on other sites

The RB20 head won't go on without major work to the water galleries. These need to be welded up re-drilled otherwise you will have water entering the cylinders. The other problem is that the combustion chambers are too small & the compression would be too high. The head to use on the RB30 block is the RB25/RB26.

If anyone is interested, I have brand new RB30 turbo blocks @ $450ea & also have a RB25 head with most other bits to make a RB30DET.


Link to comment
Share on other sites

Ive talked to a person at JMS as i tryed to source 200zr mounts, and they told me that on the 200zr the mounts are the same as the R31 mounts, as the differance on the 200zr compared to the 300zx is the crossmember, and they use the normal R31 mounts.

might not be confrimed, but can try something, mounts for a R31 Rb from a wreckers would be less than $40,

but the 200zr Rb20det sump and pickup is the one that will bolt straight up to any Rb engine, and fit staright into the Z, not like the R31,R32, R33 sumps etc which need modifying, but a 200zr sump with pickup from nissan, cost around $550

Link to comment
Share on other sites

The bigger problem is the Bores. the RB30 uses ~87mm bore, the RB20 is a 79mm bore... Thats 8mm to make up either way. And the 20 has tiny valves.

A 25 head on a 30 block would be much much better.

Anyway - any RB engine will mount into a S30/S130/z31 chassis with the 200zr mounts. HOWEVER, custom mounts would place the engine lower and farther to the rear. AND either way, you almost certnally need a custom plenum, as the stock one that crosses the valve cover is high. If you put the engine REALLY low and cut hood structure, you can leave the stock plenum on. The RB26 has a front opening Plenum so that doesn't apply.

Any RB engine will need a new oil pan and sump unless its a RB20 out of the z31, but you don't want that engine, less than 200hp stock :finger: But the 200zr sump and pan will bolt onto any other RB block (as stated above)

Link to comment
Share on other sites

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
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.