Jump to content
SAU Community

Recommended Posts

A R34 GTR V-Spec II Nur is powered by the Nissan N1 RB26DETT

Identified by the number 24U marked on the block, where as the standard blocks are marked 05U.

Cylinder walls are thicker

Water cooling channels are enhanced to increase flow.

N1 Block

N1 Oil Pump

N1 Water Pump

N1 Pistons - 1.2 mm (0.047 in) top rings and were balanced before assembly but otherwise very close to standard.

N1 Turbochargers (Ball Bearing Steel internals)

Connecting rods are stronger and balanced.

Standard crankshaft is balanced to a higher level.

Cam Shafts are further balanced.

Higher flow exhaust manifolds.

rb26nur1024.jpg

I have my doubts that the 24U block really has thicker cylinder walls. From what i've seen they appear to be dimensionally identical to the 05U block.

They seem to have a similar cylinder wall thickness to the 05U block with an upper OD of the cylinder wall around 93-94mm near the top of the block. When boring to 92mm for sleeving, the 24U breaks through into the coolant galleries in a few places around the height of the large welsh plugs.

I recall reading somewhere that the casting metal used has a higher nickel content, making the material stronger. The porosity doesnt seem to be any better. I hope to have some pictures of a bored 24U block pre-sleeving inside a week or two, so I'll post them up when I get them.

Ta, If the water channels are bigger, it would stand to reason that strengthening of iron with nickel is a logical way to go; otherwise the walls would in fact be weaker. Thicker walls? I wasn't aware of that either - nor the nickel factor.

With the coolant gallery changes, it probably means just larger holes exist behind the top row of small welsh plugs. I haven't pulled the plugs on a 24U block to confirm this, but it makes sense as its the only area you can improve coolant flow into the block.

The top row of welsh plugs on the right side of the block is the main coolant gallery. Behind these small welsh plugs holes are drilled through the outer crank case, to the inner chamber in the block where the cylinders are. Coolant flows through the drilled holes and direct to the top area of the cylinders, where most of the heat is transferred to the block from combustion.

Because the coolant flows in around the cylinders and then up into the head through standardised size coolant galleries (which match all head gaskets), the holes on the top of the block are no different to an 05U block.

I have my doubts that the 24U block really has thicker cylinder walls. From what i've seen they appear to be dimensionally identical to the 05U block.

They seem to have a similar cylinder wall thickness to the 05U block with an upper OD of the cylinder wall around 93-94mm near the top of the block. When boring to 92mm for sleeving, the 24U breaks through into the coolant galleries in a few places around the height of the large welsh plugs.

I recall reading somewhere that the casting metal used has a higher nickel content, making the material stronger. The porosity doesnt seem to be any better. I hope to have some pictures of a bored 24U block pre-sleeving inside a week or two, so I'll post them up when I get them.

Ta, If the water channels are bigger, it would stand to reason that strengthening of iron with nickel is a logical way to go; otherwise the walls would in fact be weaker. Thicker walls? I wasn't aware of that either - nor the nickel factor.

I think I should have said re-enforced block rather then thicker walls...

wow.... thanks for all the info guys...

http://www.tomeipowered-usa.com/japan/nissan/jdmnissan.htm

:D

So is there a dramatic increase in power and response of an N1 engine over a standard 34 RB26? (factory tune)

I think the power output was not huge.

But due to the N1 Turbos it ran 1 Bar of boost, so power would be up a tad.

And being ball bearing turbos along with a further refined RB26, it all added up to better response.

not sure on factory tune, but after adding some straight forward mods I've gotten some amazing gains!

This!

i think the beauty of the N1 engine is more in its reliability factor cos the standard RB26 is already pretty impressive... thus u shd be able to push the nur more with its stock parts.. (stock parts being N1 items like steel bb turbos as compared to ceramic trust bearings ones :worship: ) so is that even a fair comparison? LOL :D

that said...vspecIInur .. are the ecu settings any different than the normal V spec II ?

The two 24U N1 Blocks in the current issue (#161) of PI Mag.

1) VS2 Nur

On high boost + N1 turbs + Motec M800 ECU + JUN Cams + Nismo Plenum + Bosch 044 + Sard 700cc + Sard Fuel Reg + Splitfire + Nismo Dumps + Nismo Ti Weldina Twin 90mm

Matthew-21.gif

On med boost > 323 wKw thanks to Unigroup Engineering where Yavuz needed to attend to lambda sensors and change tune

2) VS N1

On med boost + N1 turbs + PFC D-Jetro ECU + Nismo Plenum + Bosch 044 + Sard 700cc + Mine's Dumps + Mine's Front + Fujitsubo Ti 80mm

Terry-290.jpg

Both were also in Performance Garage mag #11

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

    • There's plenty of OEM steering arms that are bolted on. Not in the same fashion/orientation as that one, to be sure, but still. Examples of what I'm thinking of would use holes like the ones that have the downward facing studs on the GTR uprights (down the bottom end, under the driveshaft opening, near the lower balljoint) and bolt a steering arm on using only 2 bolts that would be somewhat similarly in shear as these you're complainig about. I reckon old Holdens did that, and I've never seen a broken one of those.
    • Let's be honest, most of the people designing parts like the above, aren't engineers. Sometimes they come from disciplines that gives them more qualitative feel for design than quantitive, however, plenty of them have just picked up a license to Fusion and started making things. And that's the honest part about the majority of these guys making parts like that, they don't have huge R&D teams and heaps of time or experience working out the numbers on it. Shit, most smaller teams that do have real engineers still roll with "yeah, it should be okay, and does the job, let's make them and just see"...   The smaller guys like KiwiCNC, aren't the likes of Bosch etc with proper engineering procedures, and oversights, and sign off. As such, it's why they can produce a product to market a lot quicker, but it always comes back to, question it all.   I'm still not a fan of that bolt on piece. Why not just machine it all in one go? With the right design it's possible. The only reason I can see is if they want different heights/length for the tie rod to bolt to. And if they have the cncs themselves,they can easily offer that exact feature, and just machine it all in one go. 
    • The roof is wrapped
    • This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
×
×
  • Create New...