Jump to content
SAU Community

Recommended Posts

I have or had a series 1 rb25det in my 240sx. I have s-tec manifold, borg warner s366 turbo with all the basic supporting mods like intake manifold, AEM EMS and exhaust. I messed the motor up and now I'm searching for a replacement.

The NEO rb25's are getting pretty cheap over here in the states so I am considering converting over. I read on SAU about the neo motor being an all around better foundation than the basic rb25det. Having the solid lifters, rb26 rods and vct makes me want to upgrade this go around. Everything I have will swap right over including the wiring harness. I'm using GM coil packs and the sensors that are required for the AEM like the IAT and MAP.

If you are using the AEM EMS then it is required to swap out the CAS oem disk with the new one that AEM sells. This disk works only with the series 1 CAS. I've been doing tons of research and I can't find anyone that has used the AEM ems with a rb25det series 2 or neo with the black plastic CAS.

So I was thinking if need be I could install the neo RB25det engine and just convert the neo cams with the series 1 cams in order to use the series 1 cas.

-Is this possible??

-Will the AEM EMS work with the NEO CAS?

No cant swap cams. Hydraulic cams in solid lifter valve train = no.

If AEM says the disc will not work with a NEO then it probably wont work.

Change to a crank trigger system or get a CAS disc custom laser cut.

Besides mega squirt what other stand alones are out there that uses the crank trigger system?

If I don't convert my standalone then I guess I have to stay with the series 1 huh??

Err most aftermarket ECUs will happily read a hall effect or VR sensor from a crank trigger.

If the AEM cant then its not a very good ECU.

Link, adaptronic, motec, haltech, megasquirt, autronic, vipec etc etc can read a simple hall effect input. Although I believe the megasquirt prefers a VR sensor.

  • Like 1

Is it possible to use an R32/33 RB26 exhaust cam in a Neo head and and retime it ? Solid cam so to speak with the right CAS drive ?

It may pay to research the base circle diameters of RB26 and RB25 Neo exhaust cams .

Just a thought cheers Adrian .

Edited by discopotato03

Neo cams have higher lift so good to keep. For most cars swapping the CAS type just involves reversing the wiring so I would have thought it possible to make it work even with your aftermarket ecu.

I always knew that the lift and duration are different on all cams but what matters is the gap between the cams and the lifters right?? I've heard about people installing rb26 cams into an rb20 and swapping the s1 cams with the s2 cams.

Neo cams have higher lift so good to keep. For most cars swapping the CAS type just involves reversing the wiring so I would have thought it possible to make it work even with your aftermarket ecu.

I know I could do that. I would hope that what ever flaw that the s1 CAS has might be corrected in the NEO cas....

Wouldn't it just be easier to do what you have to do to fit the right CAS onto the cam? You could manufacture an adaptor, or you could weld the end of the cam and remachine it with the right drive. The options are bound to be more plentiful.

There is a local machine shop that has been around for years. I'm sure it would take some sort of computer program and nifty machinery to get this done. Might not be worth it doe.....

A good machinist could do pretty much anything with a lathe, a mill and a pair of verniers.

I wasn't suggesting it as the big solution, just offering up some alternatives. Interfacing one rotating assembly with another rotating assembly is something that car modifiers have been doing since forever. Used to get done with various distributors in order to get electronic ignition onto older engines (as an example).

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


  • Similar Content

  • Latest Posts

    • Nissan/Pitwork is fine stuff. HKS is just marketing wank. I personally wouldn't do the idler if it is already new. If it looks and feels fine, it is fine. But as D says - it's cheap to add it to the job. The water pump ditto. Even more so. If it show no signs of problems, then it is nearly new - leave it.
    • 1. I can't see a location on your profile but you do mention GBP so I'll assume you are in UK. In Australia, CBC make a timing belt kit with the gears and idler and tension bearing and that is what I use without any problems. I'm sure OEM or HKS are also fine but I wouldn't pay extra for HKS over anything else. 2. Yes, I would always change the idler and tensioner and the stud and bolt that hold them in. Assuming they were all done last time it is highly unlikely you would have a problem, but they are very cheap to add to the job considering the time it will take anyway.  3. No, you don't need to lock them as such (I think that is more for engines without timing marks), but you should make sure they move as little as possible once the belt is off as you can hit pistons on valves if they move too far. As always, make sure you line it all up to top dead centre with the timing marks aligned before you take the old belt off.
    • How to wreak havoc at a bogans party... Swap out the goon bag hanging from the clothes line with oil bag... Watch chaos ensue during Goon of Fortune....
    • Hey everyone,   I’m looking for some advice on replacing the timing belt on my RB25DET Neo-powered 1998 Skyline. The engine was fully built about five years ago, including a fresh timing belt, water pump, and other essentials. However, since then, the car has only covered around 2,000–3,000 miles. It’s currently making around 650hp.   Even though the mileage is low, I know timing belts have a time-based lifespan too, and most recommendations suggest changing them every five to six years or 50,000 miles. Since I’m at that time mark, I’d rather not take any risks and plan to swap it out soon.   A few things I’d like to hear opinions on: 1. What’s the best belt for this setup? Should I go with an OEM Nissan belt, or is the HKS fine-tune a better choice given the power level? 2. Would you bother replacing the idler pulley and tensioner at the same time, or only if they show wear? 3. When swapping the belt, is it necessary to lock the cam and crank gears in place, or is lining up the timing marks enough? I’ve seen different approaches, and I want to make sure I do it right.   The water pump was changed with the rebuild and isn’t run off the timing belt, so I don’t see a need to replace it again. I just want to make sure I approach this the right way.   Any insight would be much appreciated. Thanks!
×
×
  • Create New...