Forged pistons on 25 rebuild

[nd4spd]

SR20 ARP bots are the same for RB series motors, They will work with GTS-T rods and GTR Rods. The only problem is they come in a pack of 4 so you have 2 bolts left over.

Wrong sorry, SR fit RB25 you use VG30 for RB26.

[BBQ]

That’s funny, Because my motor has just been assembled from the machining place and they used SR20 Bolts, checked them with the standard rods against the 26 rods and they were fine.

[N I B]

Trust me its tru we do many RBs a month.

[BBQ]

Wrong sorry, SR fit RB25 you use VG30 for RB26.

Ok lets get somthing stright here... Your saying that Sr bolts won't fit on Rb26?

Are you talking about the motor or the rods ? because I'm talking about the 26 rods with a 25 Crank ?

[B-Man]

I have been shown ARP SR rod bolts on a GTS-t rod (you don't need the crank) just put the rod bolt thru at the big end and from what I saw, the nut only screws on about three turns of thread - leaving the nut half on and half off. Didn't look very safe to me.

* Caveat to this is what I was being shown was exactly what I had been told the bits were.

[BBQ]

The ARP SR bolt is going on a Rb26 Rod not 25 ? Can any one confirm if they will work ?

[B-Man]

Yeah - what we need is for someone to take pics - I also wanna see the difference between a GTR Rod and a GTS-t Rod (standard).

And also the reason why GTR Forged Rod (aftermarked eg Eagle, etc) won't work on a GTS-t - ??

:confused:

[BBQ]

Nup they work fine, we have just done 2 motors one with Forged Pistons and Forged crower rods. Using RB26 forged crower rods on a RB25.

Also I will take photos of my setup with, Rb25, using Rb26 Rods and Sr20 ARP Rod bolts. to confirm they work. When we checked the rod bolts the SR's were actually longer then the standard RB25 Rod bolts.

Also the photo attached is of the current Rb25 We built, with the forged rb26 crower rods and Arias Pistons.

I will upload another one before we put the sump on.

[INASNT]

hmm cant see the pistons and rods in that pic

Got any pics of the engine being assembled?

[N I B]

All after market GTR rods fit RB25s.

[BBQ]

All after market GTR rods fit RB25s.

Steve,

I have a question for you... Tell me the reason why Sr ARP bolts won't work on Rb26 Rods ?

[PHaT MR30]

what if the RB25 rods have been balanced, shotpeened and linished, and possibly being crygen frozen?

(if you've got em use em ^)

[N I B]

To long.VG are better.

[B-Man]

Nup they work fine, we have just done 2 motors one with Forged Pistons and Forged crower rods. Using RB26 forged crower rods on a RB25.

Also I will take photos of my setup with, Rb25, using Rb26 Rods and Sr20 ARP Rod bolts. to confirm they work. When we checked the rod bolts the SR's were actually longer then the standard RB25 Rod bolts.

Also the photo attached is of the current Rb25 We built, with the forged rb26 crower rods and Arias Pistons.

I will upload another one before we put the sump on.

Hmm - that engine bay looks familiar

[cameron]

hmm cant see the pistons and rods in that pic

Got any pics of the engine being assembled?

Here is a picture of the Forged RB26 Crower Connection rods on Arias Forged pistons in a RB25DET

[nv033]

can BBQ or SST answer a few questions........u seem to have a bit of experience in this particular discussion....

i think the forum has agreed that rb30 rods are capable of pushing 400rwkw....ive seen many 3L punch out ~350rwkw on standard rods and are thrashed day in day out...

the weekest link being rod bolts...if u address this, shot peen them....wouldnt it make the rod pretty reliable??

a rb30 rod is physically thinner than a rb25 if i can recall......wouldnt this then make the rb25 rod physicallly stronger???

i just dont hear of rods shooting through blocks that often......

i also agree with peoples thoughts of revs killing rods....8000rpm i figure would be within the grasp of a shotpeened and rodbolted rb25 standard rod.....if i make 180kw at this figure the rod spins with the same rpm as when i make 300+kw....is this change required?

what i dont get is when u upgrade the pistons and rods to forged items.....y leave the crank STANDARD???

obviously u will think twice about reving ur motor to 10,000rpm???? or does it mean u can rev to 9,000rpm???

is it worth the ~$1500 upgrade ?

(obviously it is.... if ur pockets are deep enough, but what if they arent?...which i think that is what this thread is about)

y dont people address the crank too???......everything is rotating and pumping on one another isnt it??? well thats what i think...feel free to comment

[N I B]

Nissan cranks are very tough,ND4SPD turns to 10000+rpm and has never given any crank problems and an RB25 crank is a little shorter in stroke but the same build quality as a 26 crank so dont worry about hurting the crank if your build is done right.

As i said earler i have never seen any RB rod fail other than its bolts just a set of GTR rods are cheap peace of mind.

[cameron]

what i dont get is when u upgrade the pistons and rods to forged items.....y leave the crank STANDARD???

obviously u will think twice about reving ur motor to 10,000rpm???? or does it mean u can rev to 9,000rpm???

Brand new from japan

Tomei Crankshaft is $5,697.50 + $500 shipping and maby another $400 on import tax and duty.

forged pistons $1500

Forged con-rods $2400

Thats already $10,497 then if your doing the usual upgrades with bigger turbo, injectors, fuel pump etc:

Turbo $2000

Injectors $1000

Fuel pump $450

Z32 AFM: $460 - brand new

GReddy plenum: $1400

Apexi PFC: $1100

boost solonide for pfc: $350

etc... thats total of $17,257

Don't forget your machineing bill from the engine reconditioner - $2000 +

As steve stated the nissan cranks are very strong,

With forged internals you can rev you engine as much as you like but your (rb25det) head wont handel it eg: Cam shafts, valves, valve springs etc

Hope that helps,

[BBQ]

can BBQ or SST answer a few  questions........u seem to have a bit of experience in this particular discussion....

i think the forum has agreed that rb30 rods are capable of pushing 400rwkw....ive seen many 3L punch out ~350rwkw on standard rods and are thrashed day in day out...

the weekest link being rod bolts...if u address this, shot peen them....wouldnt it make the rod pretty reliable??

a rb30 rod is physically thinner than a rb25 if i can recall......wouldnt this then make the rb25 rod physicallly stronger???

i just dont hear of rods shooting through blocks that often......

i also agree with peoples thoughts of revs killing rods....8000rpm i  figure would be within the grasp of a shotpeened and rodbolted rb25 standard rod.....if i make 180kw at this figure the rod spins with the same rpm as when i make 300+kw....is this change required?

what i dont get is when u upgrade the pistons and rods to forged items.....y leave the crank STANDARD???

Originally this thread was started about upgrading RB25det Internals,

The week link in an rb25 motor is usually the Ring lands on the standard pistons, and the Con-Rods once you start pushing serious power out. It becomes a reliability issue, to upgrade the rods while you’re doing the pistons at the same time.

I know of many rb25 motors pushing rods out the block that’s why a cheaper alternative is to upgrade to the Rb26 Rod system. So you don’t have to incurring the cost of forged items up front.

The crank as many other people all ready know, is a reasonably strong item in the rb series motors. That’s why it doesn’t appeal to skyline owners who want reasonable horse power on a low budget. As Jun has stated the cost of a crank from Japan isn’t cheap. And not viable until your planing on competing against GTR700.

The actual size of the rods dose not determine its strength. If you compared the standard rb26 rods against the forged rb26 rods they are not really that much bigger in physical size, What actually makes them stronger is the material compound they are made out of. Hence the process of forging.

As for rod bolts you would be crazy not to replace them with New blots or at-least ARP blots to sustain the integrity of your motor.