R33 Rb25de Oil Pump Same As Rb25det?

[SKiT_R31]

Hey All,

The time has come to rebuild my RB25DE+T and convert it into an RB25DET (for my 100 thou service).

Is the oil pump the same? I've never had an issue with oil supply, but want to make sure its going to hold up (while i have the engine out). I do have an old blown RB25DET block to pilfer shit from, but there is no point swapping if they're the same (esp. since mine has less km plus i know its functional).

Trying to do this relatively cheap as I am not loaded, buying pretty much everything from the US since the Aussie dollar has near hit parity, makes things heaps cheaper - Also doing all the work myself.

At the moment my shopping list is;

8.0:1 - 8.4:1 CR forged WISECO pistons, inc rings, wrist pins and locks ($750 + $90 postage)

ACL Rod & Main Race bearing's ($135 + $40 postage)

Full RB25DET gasket set ($90 + $55 postage)

RB25DET Timing Belt, Idler and Tensioner ($125, combined postage ^) + Water pump ($70)

^ Parts total is roughly $1500 after random extra's (I'll replace exhaust studs, etc)

Is there anything I am missing? I am going to fit the factory RB25DET water->oil cooler (that sits where the oil filter goes) and would like to fit the RB25DET oil squirters to the N/A Block, does anyone know what is involved in this (i.e. does the N/A block have the mounts or whatever??).

I'll probably fit an adjustable cam gear for more ideal cam timing (as N/A is supposedly different)...

Will get this done before Christmas, possibly run it in on stock turbo then see where I go from there. Down the track I'd like to fit a GT3071, Greddy plenum & PFC, and possibly up the rev limit within a safe range (~7500rpm??) as I have had experience with Greddy plenums and they seem to push power past the limiter (and I could do with the extra top end).

Keen on opinions...

Ta,

-Dan

[DR 32R]

Fork out for a crank collar and a Nitto oil pump, you could save on yet another bottom end for a while.

[SKiT_R31]

But i would then need oil restrictors?

[DR 32R]

Yes, Unlike other parts oil restrictors are cheap! you could do without the oil squirters with quality pistons. Most people would use a quality main and head stud kit, and a metal gasket. You could find RB26 rods, some H beam rods are as low as 700.

[SKiT_R31]

Interesting...

I could get a WISECO piston and Eagle H Beam rod kit for another ~ US$300 (including "IARP SERIES 2000 BOLTS"), but I was under the impression the crank should be re-balenced with a rod change...?

Edited October 26, 2010 by SKiT_R31

[zebra]

Why are you going so low on compression?

No need for ARP studs unless you want 1000hp

[DR 32R]

Why are you going so low on compression?

No need for ARP studs unless you want 1000hp

He's probably tired of too much compression with his NA motor. Most builds are in the 9:1CR. I think he should get it balanced any way.

Edited October 26, 2010 by WHITE gtt

[DR 32R]

Interesting...

I could get a WISECO piston and Eagle H Beam rod kit for another ~ US$300 (including "IARP SERIES 2000 BOLTS"), but I was under the impression the crank should be re-balenced with a rod change...?

You've got me looking at US prices, good luck with it. Have you factored import duty in as well?

Edited October 26, 2010 by WHITE gtt

[zebra]

He's probably tired of too much compression with his NA motor. Most builds are in the 9:1CR. I think he should get it balanced any way.

Ive had RB25DET's with 8.5:1 and 9:1, the 8.5:1 motor sucked balls compared to the 9:1 engine.

[SKiT_R31]

Yeah, the power I'm after is reasonably tame, somewhere in the mid 200's (as a daily), but I'd rather over build as I've been known to get carried away.... I'm really tempted to have a play with nitrous for the lols as I want to keep a reasonably responsive turbo for track/hill climbs/driving, but wouldn’t mind power on a button for drag days, etc.

I've gotten a bit sick of my N/A+t, it makes a healthy 201kW at all four on 11psi, and managed a 13.1 1/4 mile. But I’m bored and want more, it needs a 7GPH 150psi water+meth spray nozzle on any boost above 6psi at stock ignition timing. I'd like to remove the water and just run it on fuel like E10 95ron (cheapest fuel down here, 25c/L cheaper than BP ultimate), run whatever boost and not have the stress of watching my egt's at their limits. I've done the high comp road to the death, I’ve sill got a >~13:1 N/A car, an RB30DET AND and RB30E+T...

And I have a feeling this motor has had a headshave before... It doesn't seem to be able to handle as much boost as it should, reads about 190psi on all pots...

Meh, regardless I think low comp is the route I'll take this time, plus they are the best value pistons I can get...

Stamp duty is only for $1k+...???

Edited October 26, 2010 by SKiT_R31

[DR 32R]

that's a very good piston price!

[iseekool]

Yeah, the power I'm after is reasonably tame, somewhere in the mid 200's (as a daily), but I'd rather over build as I've been known to get carried away.... I'm really tempted to have a play with nitrous for the lols as I want to keep a reasonably responsive turbo for track/hill climbs/driving, but wouldn't mind power on a button for drag days, etc.

I've gotten a bit sick of my N/A+t, it makes a healthy 201kW at all four on 11psi, and managed a 13.1 1/4 mile. But I'm bored and want more, it needs a 7GPH 150psi water+meth spray nozzle on any boost above 6psi at stock ignition timing. I'd like to remove the water and just run it on fuel like E10 95ron (cheapest fuel down here, 25c/L cheaper than BP ultimate), run whatever boost and not have the stress of watching my egt's at their limits. I've done the high comp road to the death, I've sill got a >~13:1 N/A car, an RB30DET AND and RB30E+T...

And I have a feeling this motor has had a headshave before... It doesn't seem to be able to handle as much boost as it should, reads about 190psi on all pots...

Meh, regardless I think low comp is the route I'll take this time, plus they are the best value pistons I can get...

Stamp duty is only for $1k+...???

That's right anything under 1k there is no duty.

[dori34]

hey mate, the NA block does not have the mounts for oil squirters so you can either run without them or get a RB25DET block which you can pick up cheap occasionally.

As your head is coming off, you will need new head studs, so get some ARP items - do not reuse your old ones.

since the head is already off, get oil restrictors installed and a head drain kit as we all know RBs have issues with returning oil from the head to the sump.

Stock rods are fine but if you want a cheap upgrade then get GTR rods and fit ARP bolts to them.

take your crank to a crank specialist and get them to check it out, it may or may not need to be polished depending on its condition.

if u got the dosh, get a greddy plenum, makes the engine bay look so much better and the shorter piping means better response.

as for the oil pumps; de and det both bolt up, but Nissan list different part #s for both motors so i assume they are different.

why not fit a N1 item along with a crank collar to your crank for added peace of mind?

collar $100

$200-$350 to fit & balance

gl mate, post up a build thread

[SKiT_R31]

Yeah cheers, I reckon I will when I get it all started.

Head studs are something I've been considering, since they really should be replaced anyway plus they are just more reliable when torqueing, I can source some for $176 posted. GTR rods for Strength? Weight? I can get ARP rod bolts for $110, or "Forged ultra-light I beam" rods which include the bolts for $500, but not really sure if it’s really necessary for my power goal, also cautious about changing rods as I thought the crank would need the counterweights re-balanced?

Does anyone know the stock piston and rod weights? Out of curiosity...

Really trying to avoid taking it anywhere for anything more than a head shave/acid dip, I'm in Tasmania and most workshops are unreliable and very expensive. And even some basic things (like crank balancing) needs to be sent up to the mainland. Put it this way, if I gave them all the gear now I doubt I'd get it back by new years and I'd owe more than the cost of the original components.

So for now I'd rather limit what I did to it to keep it within what i can do myself.

I know everyone screams to get a new oil pump for peace of mind, but if I maintain the stock rev limit and just fit restrictors/return, surely I'd get away with the standard pump (After all, I'm not rebuilding because my bearings are shot). Just don’t want to spend the money if it’s not absolutely necessary (I’d at least inspect and fit the turbo pump though).

As for compression, I need to do the calculations for compression and clearances, but I'm pondering fitting the low comp forgies (8-8.4:1) and machining the block to sit them above deck height to increase compression and compensate for the head gasket (better squash, remove HG hotspots and more focussed initial pressure - with domed head and dished piston?)

Hmm, lots to think about. I like to take different routes to keep things interesting, no point having the same parts and power outputs as every other skyline on the road .

[zebra]

Even if you just go with GTR rods, you will need to balance the lot (they are heavier than 25 rods)

A Decent Oil Pump is a 90% must and a crank collar is an absolute must (do it once do it right), beacuse you dont wanna be pulling the motor back out with a dead crank because the oil pump broke.

Go with 9:1 for the compression! unless you plan to run 30psi of boost.

[SKiT_R31]

Ugh, I can see how the cost can quickly skyrocket... I can do an N1 RB26 pump, crank collar and 2x 1.3mm restrictors for ~ $450 posted, which is affordable (but I really couldn’t manage the >$1k-$1.5k brand name pumps). The main issue here is that I'll have to get the crank machined & the collar fitted, which means i may as well get the lot sent off and balanced... I might find a Stagea block to build up...

As for compression, I was just a bit sick of the higher compression motor but after driving some low comp's I think I'm over it .

The way I see it, on my current setup (ignition timing/cam timing/tune etc) on 7PSI the engine should have a dynamic compression ratio of 15.5:1. This is the same as a turbo motor on ~10.5psi, or an 8.0:1 forged motor on 14psi (or 8.4:1 on <13psi). The way I see it, as long as you’re in boost (and are running the difference extra) it should be equally as responsive, dependant on ignition timing possibly better. It’s the off boost that is the worry, especially with larger turbo's and because of this and it being my daily; I am going to run higher compression than I said before.