Ok Nissan tech.. Im not full of knowledge on the S-chassis or the Nissan engines.. Ive been in the Mazda and Mitsu sides of the forums for a while.... But I digress..

I have an RB20 powered s14 the car got water in it and popped the block. Cylinder 6 has a nice viewing port now.. LOL I want to upgrade to an RB25. My question is : How much switching/re-wiring/re-fabing might be nessasary to make the swap?

I have basic fabbed/homemade mounts and can fab new ones with no problems. So no big deal.

I have installed engines before. So im used to the in/out procedures.

I swapped my NA engine into my T2 Rx7, so im pretty familiar with doing re-wiring..

I just had no part of the install for the 240 and like I said im not familiar with Nissan..

So any help would be cool..

 

off of the top of my head.

you can use the rb20 tranny. IIRC it just isn't quite as beefy as the rb25 tranny. but it should hold up for a while.

the mounts should be the same. just swap the rb20 mount brackets onto the rb25 block and it should drop right in.
i don't remember if the clearance issues change between the two or not. Might need to do some engine-to-hood clearance fiddling to get it right.

beyond that, it is just going to be a normal engine swap. pretty sure any modifications/fab work that would be needed is already done once you got the rb20 in it.

again, this is just from what I remember off of the top of my head, and i've personally never done this swap, so take it with a grain of salt.

 

Thanks for the help, I actually just decided to get another RB20 I picked it up this morning. Im gonna spend the difference in aftermarket parts and OE replacements to keep it fresh.

Now just comes the part of fixing all the problems with my "in car" harness since there is some shoty wiring on that and the new RB harness has a few cut wires and missing sections. (no maf or egt harness)

It seems tough hunting down a decent schematic for the conversion.

But again thanks for the reply.

 

swap the brackets from the 20 onto the 25, your 20 clutch flywheel n tranny will bolt up, no clearance issues since the blocks are the same dimensions.

swap the coils from the 20 onto the 25 , your harness will work everywhere besides the injectors, i switch the rail to a top feed rail and go with 550s at the least and a tune.

good luck! hope you love rbs as much as i do

 

Well the install/reinstall is going... but slow. I ordered a few parts for it not. The engine seems to be in pretty good condition. It has JDM service stamps on it and alot of the seals have been in good condition. I may need to swap out turbos soon, but for now I just have to get it running.

I got one of the basic EBAY intake manifolds for it, not sure how thats gonna go. It seems way easier to get parts for the 25 then the 20.

Im saving all my sensors and harnesses from the old engine to keep as spares. I just need to get it done. LOL at this point im ready to get it back on the road and rip shit up!