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RB30 Q's

quincy777

By quincy777,
in Engines & Forced Induction

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quincy777 Community Regular

quincy777

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Hi all,

Couple of things to clarify about rb30/25 conversion.

I have read threw the sticky thread, and had some great imput from a couple of guys but need to clarify different answers as I have the block and head ready and waiting.

1. Using sk's 475 hp version of conversion. standard rb30 pistons with ceramic crowns I understand are not the weak point for this power, correct? Does this include boost of upto 20psi? If I have to have forged pistons to be safe - which ones to keep compression high?

2. If standard pistons are ok for above which rings to get?

3. GTR cams/springs, for this power do I need them? or will the rb25de ones be ok upto 250-300rwkw mark.

Thanks for your help guys, just didn't want to find out mistake or waste of money after I have finished.

Cheers

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StockyMcStock Proficient

StockyMcStock

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consider that with a properly sized turbo (GT35/40 1.06 rear for example) you will be hitting 450rwhp at about 15 psi, judging on what other people have got with decent tuning. the pistons will be fine unless it pings. in which case forgies will last about 2 seconds longer than cast pistons before destroying themselves. the rods are what you need to worry about. standard RB30 rods prepped (stress-relieved then shotpeened) will get you to about 300rwkw reliably, but i wouldn't push them to 7000rpm too regularly, know what i mean? :P

GTR springs could be worthwhile if you are using a DE head - apparently the seating pressure can be a bit iffy on them. or just get it checked by a head specialist and see what sort of pressure they're actually getting.

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drunkenmaster Community Regular

drunkenmaster

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I have just spent quite a bit of time going through the RB30 thread and also various websites and the pdf but one question which is brushed over but not directly addressed, well as far as I can see, is do all RB blocks share the same engine mount bolt pattern, that is, are all RB engine mounts fully interchangeable?

I thought I would post here rather than continue the cluttering of the RB30 thread.

Thanks guys

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TTT Grand Master

TTT

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1.) using SK's 475hp example, you will also have read his main key in that result.

I think it was something like... TUNING...TUNING...TUNING... and more TUNING...

Also, he got that 475HP at the engine using an old T04 of some sort at 1 bar boost. and at 6200rpm was max power.

the low RPM and low BOOST and careful tuning is the reason that engine has over 70,000kms on it and still going.

2.) I believe he used OEM rings, bearings and gaskets.

I think that CUBES PDF also has what part numbers and brands he used. The PDF is in his signature.

3.) Cams should be fine for that figure from other's finding. The Valve springs though... I'm not sure.

Joel (CUBES) and his mate both bought R32 RB25de heads and sent them away for testing.

Joels was fine but the other one had seating issues..

I think the GTR valves will set you back about 300 - 400 dollars and that would be fine for the power you are after.

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Sydneykid Grand Master

Sydneykid

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1.) using SK's 475hp example, you will also have read his main key in that result.

I think it was something like... TUNING...TUNING...TUNING... and more TUNING...

Also, he got that 475HP at the engine using an old T04 of some sort at 1 bar boost. and at 6200rpm was max power.

the low RPM and low BOOST and careful tuning is the reason that engine has over 70,000kms on it and still going.

2.) I believe he used OEM rings, bearings and gaskets.

I think that CUBES PDF also has what part numbers and brands he used. The PDF is in his signature.

3.) Cams should be fine for that figure from other's finding. The Valve springs though... I'm not sure.

Joel (CUBES) and his mate both bought R32 RB25de heads and sent them away for testing.

Joels was fine but the other one had seating issues..

I think the GTR valves will set you back about 300 - 400 dollars and that would be fine for the power you are after.

The engine has standard Commondoor everything, rings, bearings, seals the lot.

Yep the trick is low boost, low rpm, keep the power sensible (resist the urge for that extra 20 rwkw's) and TUNING.

It is not a simply swap to stick GTR (solid follower) valve springs in a GTST (hydraulic followers). You have to modify the spring seats and the retainers and set up the seat pressure with shims. That's why we went for 1 bar, the RB25DET springs handled it easily.

:D

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quincy777 Community Regular

quincy777

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The engine has standard Commondoor everything, rings, bearings, seals the lot.

Yep the trick is low boost, low rpm, keep the power sensible (resist the urge for that extra 20 rwkw's) and TUNING.

It is not a simply swap to stick GTR (solid follower) valve springs in a GTST (hydraulic followers).  You have to modify the spring seats and the retainers and set up the seat pressure with shims.  That's why we went for 1 bar, the RB25DET springs handled it easily.

:)

Thanks for your help guys.

So keep to 1 bar of boost as max, don't rev beyond 6500 regardless of springs and all will be ok.

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Bl4cK32 Grand Master

Bl4cK32

Posted
Posted
I have just spent quite a bit of time going through the RB30 thread and also various websites and the pdf but one question which is brushed over but not directly addressed, well as far as I can see, is do all RB blocks share the same engine mount bolt pattern, that is, are all RB engine mounts fully interchangeable?

I thought I would post here rather than continue the cluttering of the RB30 thread.

Thanks guys

The mounting points (bolt pattern) on the blocks are the same, but the actual engine mounts are different between all model rb's ive seen. Rb20 is different to rb25, is different to rb26, is different to rb30 ....

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drunkenmaster Community Regular

drunkenmaster

Posted
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The mounting points (bolt pattern) on the blocks are the same, but the actual engine mounts are different between all model rb's ive seen. Rb20 is different to rb25, is different to rb26, is different to rb30 ....

Appreciate it :kewl:

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