First time build on my rb25, need some guidance

Discuss the RB20, RB25 and RB26 series engines.
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ANVIL
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Car: RB25DET S13.5
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So i have been saying this for years to myself and probably made a few posts too but life happens and plans always change but for now im on track to finally do an internal build on my my s1 rb25det over the winter. Im a n00b when it comes to this so advice will be greatly appreciated, and every detail will matter.

As for now my setup, i dont even know if its achievable, id like to get low 400whp on pump gas and mid 11 1/4. Isis manifold, 650cc inj, hypergear turbo. Im really after reliability on this setup and also not having to rebuild the block if i choose to go for a 500+ whp setup in the future.

At the moment im highly considering eagle rods with CP pistons.

My build/budget list so far:
Cp pistons/rings
Eagle rods
Cometic head gasket
Arp head studs
Arp rod bolts
ACL race bearings
Oil pan gasket
Timing belt

Some questions i have are...
What other parts should I budget for?
Is CP worth the extra money over wiseco?
What compression is recommended? (Was thinking 9.0)
Should I upgrade my oil pump?
Do I need to do the crank collar extension?

Thanks in advance for any input!


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ANVIL
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http://pages.ebay.com/motors/link/?nav= ... 94&alt=web

Seems like a great price but kinda iffy to buy used off of ebay. What do you guys think?

Eagle H beam rods + ARP bolts $275

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ANVIL
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Also advice on best places/pricing to buy from would be appreciated. Working through emails with titan motor sports about packaging everything into 1 purchase

Yellow4g63
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http://www.spoolimports.com/ I was going to buy stuff from them when I had the thought to build my motor.

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ANVIL
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Should i get my head resurfaced when its all apart?

What head gasket should i use?

What exactly are the benefits to micro polishing a crank?

RRRRB
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Joined: Wed Jun 01, 2011 9:31 am
Car: 98 RB powered S14
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ANVIL wrote:At the moment im highly considering eagle rods with CP pistons.

My build/budget list so far:
Cp pistons/rings
Eagle rods
Cometic head gasket
Arp head studs
Arp rod bolts
ACL race bearings
Oil pan gasket
Timing belt

Some questions i have are...
What other parts should I budget for?
Is CP worth the extra money over wiseco?
What compression is recommended? (Was thinking 9.0)
Should I upgrade my oil pump?
Do I need to do the crank collar extension?

Thanks in advance for any input!
I think CP pistons are better than the Weiscos, however im currently running Shelf weiscos and have Hit 800whp with my setup, also using eagle rods.

I would avoid Cometic head gaskets as there are alot better options out there such as Tomei, apexi, power enterprise, etc.. Im using an Apexi gasket.

Arp rod bolts are already in Eagle rods, if you want to save a little money, using RB26 rods with ARP rod bolts will easily be safe for 600whp+ but you're only saving a couple hundred bucks all said and done.

There is no oil pan gasket, its sealant, If you buy a gasket kit from Nissan it will come with all seals and gaskets and includes the recommended sealant for sealing the oil pan.

I would 100% recommend installing a crank collar i just dropped off a crank today to get done, 90 bucks to have it installed... You can use Spools setup it comes with a crank collar and oil pump gears and is a spline drive setup simular to the 2JZ. Lot of options out there for that, honestly its a whole nother subject. Im using a Tomei pump.

Compression.... Anything from 8.1 to 9.5 is fine in a street car, mine is a little lower than normal at 7.8

For referance i made 420whp with my S1 RB25 on 18psi, 92 pump and a GT3076R on a Dynojet 224x dyno. That was with a completely Stock Cylinder head and cams.

Make sure you get the Cylinder head and block surfaced, take off as little as possible and maintain a 50 or lower RA for finish when using MLS gaskets. Doesnt hurt to go thru the head with a valve grind and new seals at this point either.

If you have never assembled an engine i would recommend the help of someone who has..

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ANVIL
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Appreciate the input RRRRB! Will take it all into consideration!

Stock head with what in the block for the 420whp?

Might not be possible for me... but i can always hope. Gonna be tough with our 90oct pump up here.

Yellow4g63
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add some meth injection then.

RRRRB
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ANVIL wrote:Appreciate the input RRRRB! Will take it all into consideration!

Stock head with what in the block for the 420whp?

Might not be possible for me... but i can always hope. Gonna be tough with our 90oct pump up here.
The lower end was built, i had the weisco pistons and eagle rods at the time... but that doesnt really contribute any more horsepower over stock parts. My motor would have remained stock, but when i swapped the car i planned on just doing crank collar head gasket and studs but my motor was full of water with a badly rusted cylinder when i got it from the importer... ( JDM engine depot) who refused to help in any way.

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ANVIL
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So im waiting to hear back for quotes from a couple companys.... any other suggestions where i can get good service and pricing?

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ANVIL
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Looks like im going to be going with jgycustoms for my order. Their customer service was way better than any other place i contacted and they also do lay away plans which i may take advantage of depending on my total.

But motor hopefully comes out this weekend then i can go from there

Yellow4g63
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Are you serious about JGY? I'm from the SR20forum and nobody has anything good to say about them.

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ANVIL
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Yes ive emailed 4 or 5 different companies and theyve responded the quickest and offered their opinions. Also i showed them the other places i was considering ordering and they said they would beat the price.

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ANVIL
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Who would you recommend 4g63? I haven't officially placed my order yet

Yellow4g63
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I order from all over lol. RHDjapan is where I bought my Tomei cams, valve springs and injectors. Phase2Motortrend has good prices on things, Frsport, Mazworxs which talking to them on the phone vs email gets things done faster. I just stayed away from JGY because of the bad rep, and have dealt with shops that had reps like that. They tell you everything sweet and get your money, Then they are slow to get your parts and offer s*** customer service. In the end the money you thought you saved wasn't really a saving after all.

google JGY customs review and see where it leads you. This is top of the page and i'm sure you if you look at the forum links you will read the horror story.
http://www.ripoffreport.com/r/JGY-Custo ... are-418476
https://www.facebook.com/BoycottJgyCustoms/

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ANVIL
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Wow. I would have been the next victim. Looks like I'll be shopping around more.

Spoolinimports was one of the places i emailed and haven't heard back yet

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ANVIL
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Ok so ive decided to just peice my build together slowly in an effort to get the best deals

Looks like i will be going for

Manley H beam rods
Wiseco pistons 9:1
ACL rod and main bearings
Arp head studs
Apexi head gasket
HKS timing belt

If anyone knows where i can get any of these for a good price let me know. Although i think i have a source for the rods pistons and bearings. Specifically trying to find the apexi head gasket

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ANVIL
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Is there any noticeable difference between 8.5:1 vs 9:1 compression ratio?

Was originally planning on sticking to stock 9:1 but found a great deal on some cp 8.5

RRRRB
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who even makes a 9:1 piston? also when you look, see what the piston manufactor uses for gasket thickness when they calculate compression ratio, most of the time its not what you will be running or whats out there..

Im running Weisco pistons, and wouldnt recommend them for this application.

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ANVIL
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Ive seen several sites selling CP pistons advertise 9:1 part number SC7304

But i think im gonna get the 8.5 part number SC7307 because its a good deal. Idk how to decide for sure

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Carl H
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higher comp means more power off and on boost with less boost required to make it... assuming you have a good calibrator then the higher comp shouldnt be an issue.

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ANVIL
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Decided Ill be getting an apexi head gasket. Just curuous if are they reusable

RRRRB
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I'd do the 9.0 compression CP

I dont beleive those were available when i built my motor years ago.

The Weisco pistons are rated at 8.4 but they are also calculating that ratio with a 1mm head gasket, with a 1mm head gasket and 10.25 lift cams i only had .040 Piston to valve clearance, which is way tight.

I opted for a 1.5 mm head gasket to add some distance, but that in turn changes quench clearance and still have a tight .060 Piston to valve... Wasnt Impressed with Weiscos plan of attack.

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ANVIL
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Yeah im going with the 9.0

Seller works for a speed shoo and is able to exchange the 8.5

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ANVIL
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Man this build is adding up quick.

Should i invest in arp main studs? Can i reused the stock?

Also now im considering the crank collar extension. I was planning to have the crank micropolished and balanced anyways. Would those $67 ones on ebay work? With the set screw if i take it to machine shop when i do the micropolish and balance? Or what brand should i get and why?

If i do the collar extension should i upgrade my stock oil pump as well?

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ANVIL
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Found a raw brokerage extended crank collar.

Should i upgrade or replace my oil pump with the crank collar?

Opinions on getting arp main studs or reusing stockers???

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ANVIL
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When doing rb25det extended crank collar is it necessary to replace oil pump or upgrade it? Or will doing just the extension suffice? should be at around 400whp on new setup, what power level is it more recommeded to upgrade the oil pump?


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