240Z RB25DET conversion

[Tom2305]

Hi everyone, I am new here

I have a 240Z and was looking to do an RB25 conversion, I have done some research but it’s still a bit confusing, does anyone have a list of all the parts I will be needing to convert the RB25  to rear wheel drive and into my 240z.

Thanks

Edited July 1, 2020 by Tom2305

[GregTas]

Hi Tom,

Well I've done one, but I would say it's quite a bit more than a list of parts to buy, more a list of things to do, sort out.

I'm sure there must be a lot of stuff online that covers it.

Engine mounts made my own. I sat a dummy engine and gearbox in place and once where I wanted it worked out the dimensions for them and made them up. I believe it is possible to buy something, but might not get engine exactly where you want it..

Sump: I chopped the  bottom off RB sump and made and new one with sump at rear. You can use a patrol RB sump and do it with less work.

Gearbox: RB. Need to remove the speed sensor to fit it in the tunnel. 

Tailshaft: I used skyline shaft. Shortened to one piece. Replaced diff flange with Subaru STI 6 speed diff flange (Not easy to get locally). This flange has the same bolt pattern as Skyline shaft. So it then just bolts up.

Radiator: Both fittings on drivers side.

Plenum: Used Skyline front throttle body, but had to chop front of and realign it for induction pipe to go out the front.

Intercooler: Modified it so pipes go through the air vent holes.

Gearbox mount: Mount be able to buy one, but some have said what you can buy is not great. So might be better making your own up.

Wiring: Either get a Skyline loom and wire it in. Or better way custom ecu and do your own loom.

Time: A lot of it required.

Cost: Quite a cost even if doing all the work and fabrication your self. If you have to pay someone to do it and cost is a possible constraint, then probably not something to consider doing. Stick with good L series.

How's that for a start.

Greg

 

 

 

[Tom2305]

Thanks Greg,

You definitely clarified a lot of things I wasn’t so sure about and by the way your engine looks great

[cracker]

 

[smugley]

If you're going to put this on the road you will also have the added cost of getting it Engineered to meet your state's rules .

That might also include brake upgrades and passing emissions regulations .  

 

[gav240z]

I think Castlemaine Road shop offered engine mounts for RB conversions.

You'll want a forward facing plenum also. To do away with the over valve cover jobby on the Rb25.

Weigh up the cost of conversion vs a Les Collins built L-series. You could make some good power out of an L-series with $15-20k thrown at it.

https://www.rodshop.com.au/datsun/240z-260z/em081-nissan-engine-mounts.html

[GregTas]

3 hours ago, smugley said:

If you're going to put this on the road you will also have the added cost of getting it Engineered to meet your state's rules .

That might also include brake upgrades and passing emissions regulations .  

 

Yes that's definitely worth understanding first because it could add quite a bit more to it and influence plans for the brake and suspension upgrades.

[JDM-TOY]

You will need the following: 

Cash, Cash, Cash, Time and More Time. 

And some hair colour for the whites that will come out half way through the build.

 

Enjoy

[Cozza]

On 7/1/2020 at 10:26 PM, GregTas said:

Hi Tom,

Well I've done one, but I would say it's quite a bit more than a list of parts to buy, more a list of things to do, sort out.

I'm sure there must be a lot of stuff online that covers it.

Engine mounts made my own. I sat a dummy engine and gearbox in place and once where I wanted it worked out the dimensions for them and made them up. I believe it is possible to buy something, but might not get engine exactly where you want it..

Sump: I chopped the  bottom off RB sump and made and new one with sump at rear. You can use a patrol RB sump and do it with less work.

Gearbox: RB. Need to remove the speed sensor to fit it in the tunnel. 

Tailshaft: I used skyline shaft. Shortened to one piece. Replaced diff flange with Subaru STI 6 speed diff flange (Not easy to get locally). This flange has the same bolt pattern as Skyline shaft. So it then just bolts up.

Radiator: Both fittings on drivers side.

Plenum: Used Skyline front throttle body, but had to chop front of and realign it for induction pipe to go out the front.

Intercooler: Modified it so pipes go through the air vent holes.

Gearbox mount: Mount be able to buy one, but some have said what you can buy is not great. So might be better making your own up.

Wiring: Either get a Skyline loom and wire it in. Or better way custom ecu and do your own loom.

Time: A lot of it required.

Cost: Quite a cost even if doing all the work and fabrication your self. If you have to pay someone to do it and cost is a possible constraint, then probably not something to consider doing. Stick with good L series.

How's that for a start.

Greg

 

 

 

Great write up GregTas and yes a super today engine bay.

wheres your battery? looks like there might be an oil catch can in the standard battery location

[GregTas]

Thanks Mick.

Battery is in the boot in a battery box. Back left corner. I could have left it there, but thought better in back for weight distribution.