I realized something today...I’ve been a moderator here for some time now and I’ve been telling people to search for answers to this question and never realized how scattered and sparse the information in. So in an effort to un-ufck that situation I figured it is time for a real thread

Please add information or correct me if I make a mistake! This will be a sticky and possibly an article if it pans out well!!

First things first: any supplemental questions related to the swap (i.e. wiring) can be found here zerothread/110509

What should I replace before the swap?This is a very hard question because everyone’s budget is different. Not everyone can afford to spend an extra $2000+ worth of parts before the engine is even in. What I recommend to replace is: 1) Water pump 2) Timing Belt AND tensioner/idler pullies 3) Oil Pump 4) Clutch (possibly flywheel if you have the cash flow) 5) All accessory belts ( zerothread?id=119087 ) 6) Fuel Filter 7) Fuel Pump (replace with higher flow unit) 8) Spark Plugs (more info comming soon)Those items will ensure you have a strong running engine for a long time. They are basic maintenance items that are overlooked by a lot of people who subsequently have engine failures.

RB20Will bolt in using stock mounts and R32 crossmember. you can also use aftermarket ones from companies such as McKinney and TopHat Will use stock 5 speed driveshaftCustom downpipe may be needed for both S13 and S14Electric fans are requiredCustom throttle cable bracket may be requiredTach adapter or gauge cluster swap required for accurate tach signal

RB25Requires electric fansCustom throttle cable bracket may be requiredTach adapter or gauge cluster swap required for accurate tach signal. Then this one gets a little more complicated. MountsR33 crossmember and mounts can be used, BUT you must cut the hood skeleton or replace the factory 25 manifold with something like a Greddy unit or similar. Mckinney and TopHat make mounts if you only have a motorset and no crossmember.

DriveshaftThe cheapest route for this is to open the phone book and start calling offroad shops and driveshaft shops. You will generally spend $225-$275 for a custom shaft if you bring them the parts. They will tell you where to measure and then make the shaft.

Shops like Mckinney do make a bolt in 1 piece shaft provided you are using their mounts but they are rather expensive.

DownpipeIn a s13 the stock downpipe clears if you have mounted via the crossmember swap or aftermarket mounts.

In a S14, it’s a bit different. Using the R33 crossmember you will probably need a custom downpipe. If you use aftermarket mounts the stock R33 downpipe will work (may vary by mounts, generally it will work no problem).

RB26First, if you are considering going with a RB26, I hope you have large sums of money at your disposal. This is a very very expensive swap. Expect to spend in the 8,000-$10,000 neighborhood to do it right. This guide is going off the assumption you will be using the stock twin turbos. Things change if you convert to single. First things first, you cant use the RB26 AWD transmission without some modification to the floor of the 240sx. There are RUMORS of it fitting without modification and AWD components working but we do not have verification yet. So ffor this guide I assume you are using a RB25 transmission.

Electric fans are requiredTach adapter or gauge cluster swap required for accurate tach signalCustom throttle cable bracket may be required

MountsNo option here, you need to go aftermarket. Mckinney.

Driveshaft Same as the RB25’s requirements.

Downpipes Again, no option here. Need McKinney downpipes.

If I have missed anything or you guys want me to add something, just post it up! Thanks NICO!

lookin good, for the rb20 Ka mounts can be used WITh the R32 X member. Another small thing i had to make a custom Throttle cable bracket, no biggie though, another thing that would be GREAT is if confirmed information could be stickied,

sparkplugsbeltsetc

the interchangeable thread is helpfull but it would be nice to have confirmed info.

wont the RB20 bolt in using the KA crossmember?

ill add the throttle cable bracket stuff, i had to fab one up too.

as for spark plugs, ill try to find part numbers and add them in there lol bcpr7es for the 25 i believe...

rb20 bolts in using r32 xmember no other way unless a mount kit is used.

gotcha.

As for the rb20 sparkplugs i went to sparkplugs.com lol and It showed these for the rb20 BCPR5EIX-11 im running them now, i was told heat range 6 is what i should get, id like to change these plugs out, whats the #'s of what you guys are running on your rb20's?

rb20 turbo elbow did NOT clear on my s14 swap, but i have the hookup from a guy in australia who can make a kickass elbow that clears. also the stock tach can work, but you have to take apart the cluster and adjust the potentiometer on the back of the tach. you also need an aftermarket tach or something that reads correctly to calibrate your stock tach to.custom thottle cable is requred, but easy to make from parts from a northern hydraulic store or someplace similar.*edit*dont forget to replace the timing belt pullies too. they are as important as the belt. if they fail, its as bad as having the timing belt break

i think all the swaps require adapters for the heater hoses. and i hope you like wiring :-/

thanks, that answered a few of my questions

Seth

Bronze MFP wrote:rb20 turbo elbow did NOT clear on my s14 swap, but i have the hookup from a guy in australia who can make a kickass elbow that clears. also the stock tach can work, but you have to take apart the cluster and adjust the potentiometer on the back of the tach. you also need an aftermarket tach or something that reads correctly to calibrate your stock tach to.custom thottle cable is requred, but easy to make from parts from a northern hydraulic store or someplace similar.*edit*dont forget to replace the timing belt pullies too. they are as important as the belt. if they fail, its as bad as having the timing belt break

i think all the swaps require adapters for the heater hoses. and i hope you like wiring :-/

do you have instructions on how to recalibrate the tach? that would be some really helpfull info

and thanks for the info, clarifications ammended

My RB20 dump pipe didnt clear either of my S13's, coupe or hatch, Zenki or Chuki. Im using TopHat mounts.

Also, the headgasket is a good thing to replace while the motor is out, I did mine in about 1.5 hours no worries at all. In the car thats a whole nother nightmare.

Don't forget, if you swap the head gasket to a metal head gasket, get the head and block resurfaced. I figure I should be the one to speak up on that topic

skillzilla wrote:My RB20 dump pipe didnt clear either of my S13's, coupe or hatch, Zenki or Chuki. Im using TopHat mounts.

Also, the headgasket is a good thing to replace while the motor is out, I did mine in about 1.5 hours no worries at all. In the car thats a whole nother nightmare.

oh god, any and all work you can do on the engine outside of the car is 10x faster than once its in. Newbies, don't rush, do everything you can to the engine while its out of the car!

Any info on recalibrating the tach would be VERY helpful.

I'm running an rb20 in my s13 and am using the SAFC II for a tach as of now.

tach recalibration?http://lsauto.com/products.asp



i sent mine in to them. ill let people know how it turns out when it fires up.

Tach Recalibration.

1. Pull Cluster2. Remove Backin and Clear plastic cover for the gauge.3. Take a sharpie and mark where the needle sits on the gauge face so when you're pulling the needles off you'll know where it sits so its not screwed up when you put them back on, you can also mark the spot it sits on. 4. Remove the gauge faces.5. Where the tachometer face is... there is a variable resistor that you can stick a screwdriver in. 6. Ussually you turn it all the way to the left.7. Once you've done that, do this entire process in reverse order.

Now since all motors are a little different and so are the electrical outputs, you might have to pull it back out, an then turn it a litte more right and a little more right, to get it perfect. Just keep doing it untill you're satisfied or if you have an SAFC it makes it alot easier to calibrate.

When using the sharpie on your gauge cluster, to get the stuff off, all you need it some axe body spray, or some red zone body spray. Apply it to some cloth and dab it onto the area that the sharpie has been applied to and it will either slowly or pretty much instantly come off.

If i left out anything or you're still confused quote and reply to this.

Awesome, good job Joe, maybe add a direct link to the thread with replacment part numbers and watnot.

-Dan

im thinking about rewriting that thread completley, but not this weekend. have an event in phoenix lol

I have been compiling alot of this same info. As well as other places. I will post any additional info if you would like Kamin.

Just a second thought... This should be stickied.

We'll work on it! Once this thread has the majority of the info we feel is needed we'll clean it up and all unrelated posts will probly be deleted.

Joe, lemme know when you want to tackle that thread, i'll help get it organized.

-Dan

2 things i would like to add.

remember, if you are starting out with a rolling chassis, you will need to find the Ka upper and lower harnesses. something i didnt realize.. im currently battling this harness issue.

another thing, MAKE SURE YOUR RB COMES WITH A HARNESS! believe me, they are not easy to find. for some reason, my harness was missing. im still trying to get one.

this will save you ALOT of frustration.

would love to see a pic of Custom throttle cable bracket so i will know what i am doing. thank you

If you use the R32 crossmember instead of the mounts, how is the engine/transmission positoned? Does the engine sit too high requiring the hood bracing be cut? Is the shifter positioned correctly?

I am thinking about doing this swap and have seen that using the crossmember is an option but I haven't seen if there are problems like with the RB25.

Thanks.

Oh i had a question for you when you are doing the rb26 swap do you have to get a rb25 oil pan or can you keep the rb26 one on???

The_Rising_240 wrote:Oh i had a question for you when you are doing the rb26 swap do you have to get a rb25 oil pan or can you keep the rb26 one on???

Its been done with a rb26 oil pan. i cant remeber how well it worked out. they took out the front diff. and covered up the holes. I've seen some other ones 2 i believe. Hope this helps.

zer...83716

RB20DET Belt part numbers

I was wondering if you guys had the parts numbers for the RB20 instead of the 26 =\ my p/s is fritzing out on me, and I was wondering if anyone had the #'s for the rb20 thanks !!!

kdkjrf wrote:RB20DET Belt part numbers

I was wondering if you guys had the parts numbers for the RB20 instead of the 26 =\ my p/s is fritzing out on me, and I was wondering if anyone had the #'s for the rb20 thanks !!!

11950-04U00

I'm also curious about the custom throttle bracket. Anybody have pics?

I NEED PICTURES OF THE RB20DET WIRING DIAGRAM?

Im really considering doing the rb20 into my s13. Do i use the stock ka driveshaft or the rb?