Easy Way To Identify Neo Head

[Smity42]

Is there anyway easy way to identify if an RB25DET head is a NEO or not, without having to pulling a lifter out?

Lets assume for the sake of argument that it is a bare head with no manifolds, and may have the wrong cams installed so we can't use the CAS drive on the exhaust cam to indentify it

[The Dan]

The number on the exhaust side just above cyl 2 and 3

[Smity42]

Can you please provide a little bit more detail? Where will this number be? Under the cam cover? What about it will distinguish between a NEO and non-NEO head?

Thanks in advance for your help

[The Dan]

The number on the exhaust side just above cyl 2 and 3

[The Dan]

Let's break that down a bit:

Theres a number

It's on the exhaust side

Look above cyls 2 and 3

Read the number

Post it here

That's the only 'other' way to identify it unless you want to take photos of the inlet ports.

They are the holes on the intake side of the head.

[Smity42]

Thanks Mate, I get where you are coming from now.

Sorry I didn't quite follow at first, I thought maybe I could look at the number and determine if it was a NEO or not without having to post it up, if there was some sort of rule to apply or something. Also I wasn't sure if this number was on the exhaust side under the cam cover, or just above the exhaust ports or something. I'm guessing its not under the cam cover and will be obvious when I go and look for it.

I will get the number and post it up tonight.

Thanks again

[Smity42]

Sorry for the delay, here is the numbers from above cyls 2 and 3: 75T 12

So what does this tell me?

Edited May 17, 2009 by Smity42

[Smity42]

Also some pics of the exhaust cam/lifters. Can anyone who knows what they're looking at tell if these are solid or hydraulic?

[The Dan]

75T 12 is not Neo. It's regular RB25

[Smity42]

Thanks for your help

[MBS206]

On this path...

How can you identify a neo engine when you have the whole engine there?

[The Dan]

On this path...

How can you identify a neo engine when you have the whole engine there?

I don't know of any differences in the blocks. I'm sure there are but I've never done the research on it.

I would say the main differences are going to be on the water pipe directions/configuration. Other than that, they are all identical.

Which means it does not matter if you have neo block or non-neo block....all as good as the other.

You can put a neo head on a 33 block and essentially...it's a Neo.

[RRob]

You can tell it's standard rb25 due to the coil mounting bolts.

[The Dan]

You can tell it's standard rb25 due to the coil mounting bolts.

Good thinking.

Yeah that works too

[Smity42]

Whats different about the NEO coil mounting bolts?

[RRob]

They don't have the rails the coils mount to on a 33. And neo heads have 6mm bolts to mount them to the head instead of 8mm.

[HR31DRFT]

Can you please advise what the 75T 7 head would be?

[kitto]

Yep, thats definitely a non NEO head, You can see the lifters are hydraulic

Pretty sure the NEO head has 05L on the exhaust side. I looked at mine tonight and i can't actually remember lol.

The NEO head has 2 M6 bolts for each coil pack rather than a rail as said above. The NEO has the provision for the head breather on the exhaust side of the head above cylinder 1 but there is no hole drilled for it, just the two threads.

The NEO has Shim OVER bucket lifters. You can easily see them when the cam covers are off. You sorta have to know what your looking at, but you can easily see the shims sitting on top of the lifters.

[Rolls]

Another way to tell is the coil pack mounts are different in the neo head, different hole size and placing.

[33_drift]

So I have a stagea that’s blown a head gasket and I’m looking for a head, I’ve looked for the casting number in the place that’s specified and there’s no number that I can see, is it cast into the head or stamped