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has anyone used the arias forged pistons to suit the rb30/25 and know what compresion ratio they give? i rang rocket but they couldnt tell me

I recently bought a set of these pistons.

Pics n details are here from a previous post http://www.skylinesaustralia.com/forums/sh...&postcount=2227

The Arias specs sheet and the factory VL manual specs seems to be different.

Using a stock rb30 na head gasket and stock 25 head it's spose to make 8.6:1 but there are many variables that can change it slightly, eg skimmed head.

But to be sure to get the right comp its best to have your engine measured for a more accurate comp.

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What psi does a standard 9:1 rb25det produce when doing a compression test. Would this be the same for a 9:1 rb30det?.

The 26 ARP head stud kit (25 head) arrived today. :headspin:

To double check everything I tried fitting a stud to the block and head. Like others have mentioned in the past, the block needs to be drilled and tapped for the thickers studs. The 25 head holes also need to be made bigger.

I'm not sure on the torque settings for the head studs.

On the back of the ARP box is a listing of torque settings - see attatched pics

PS: It also has this written on the box > "The torque values represented here are intended to be for general information. Not for specific installations!"

is that the actual pistion set they list for the rb30/25 combo or are they just rb30 pistons?

I recently bought a set of these pistons.

Pics n details are here from a previous post http://www.skylinesaustralia.com/forums/sh...&postcount=2227

The Arias specs sheet and the factory VL manual specs seems to be different.

Using a stock rb30 na head gasket and stock 25 head it's spose to make 8.6:1 but there are many variables that can change it slightly, eg skimmed head.  

But to be sure to get the right comp its best to have your engine measured for a more accurate comp.

-----------------------------------------------

What psi does a standard 9:1 rb25det produce when doing a compression test. Would this be the same for a 9:1 rb30det?.

A bit of a wild card here guys , whilst sniffing around at an American site called Nissan Performance Magazine I saw mention of the Nissan VG33 . Its got me thinking that if an RB30 block was bored out and sleeved maybe the bigger bore pistons ie 89mm or whatever could be fitted . The trusty Casio says 3173cc's . I would discover this just after buying pistons ..........................

Actually these things are out here in current Navaras and the bore size is 91.5mm for the std 83mm stroke . Me thinks the humble RB30 Block would not like to be sleeved that far , even for 3353 cc's ........................ But if it could with larger valves in that 26 head ...........................

The yanks are fitting ser 1 VQ45 pistons in the VG33 for approx 3400cc .....

is that the actual pistion set they list for the rb30/25 combo or are they just rb30 pistons?

Yep it's a kit includes rings,clips and pins. The pistons are 8601 forged.

The kit suits both 26 and 25 head, the pistons are different from na and turbo Rb30 pistons as seen in the pic.

if you search back through this thread and find my name you will see it discussed numerous times. You need an adapter plate, you need an external pickup and you need to slightly mod the driveshaft side of the sump and change from studs to bolts.... PM if you are serious and ill give the rest of the details....

Fitted up the AP PFC to the R32 RB30DET today.

The base map runs fine providing you don't give it too much.

Knock levels for general driving with a tinny bit of stick is around 8.

Cold starts are good, warm starts require one to play with the accelerator to get it started. :cheers:

Apart from that it definitely runs better and feels much more linear.

my rb30 has rb20 power steer, air con and alternator mounted onto it

the rb30 harmonic balancer didnt line up with all the pullys correctly

we put an rb20 harmonic balancer on it and everything seems to line up fine... :S

what belts should i use? rb30 or rb20... is there any different.. maybe in height due to rb30 block??

what belts should i use? rb30 or rb20... is there any different.. maybe in height due to rb30 block??

I also used the RB20 harmonic balancer.

Use all the RB20DET spec belts.

Did you modify the rb20 powersteer bracket? As you have to.

Unless you use a R31 RB30E bracket.

  • 2 weeks later...

Probably the least techincal question asked in this thread, but here goes:

I went to fit my RB30DET on the weekend and realised I dont have the engine mount to block bolts.

Does anyone know what width, length and thread pitch these are suppose to be so I can buy some replacements?

More bolts I noticed I was short on were the oil sump to block bolts, does any one know the sizes of these as well?

some very useful information in here guys well done! was just wondering. im going a quicky budget route in my coupe. i have a 26head, larger injectors aftermarket comp , bigger fuel pump etc etc. now i am going for a block. i am really curious if i could get a standard vlt block and slap the head on it with all the other gear. how long do you guys reckon it would last with the right tuning? remembering that i would not run more than 15psi on a gt35 turbo. just to be safe.

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