Pros And Cons Of An Rb30 Engine?

[Sayajin]

Okay guys. I am in the process of getting ready to build the living crap out of my RB26 including a 2.8L Tomei Stroker Kit. I had previously considered going with an RB30 however I was under the impression that with the RB30 you lost quite a bit of revs. This was my primary reason for steering away from it as I am very rev happy. As of yesterday I was informed that my understanding was incorrect. You dont really lose much revs. You can still rev an RB30 to 9500rpm and such safely.

This brings me to the reason for this thread. First let me say I am not trying to make this an RB30 vs Stroked 26 war. Also I am not asking what the RB30 is or what it does. I know these things as I have researched it. My question is much simpler then that.

If the price to stroke and build and RB26 is the same as the price to buy a brand new RB30 fully built. Why the hell wouldnt you buy the RB30? I mean with all the benefits of the RB30, torque, crazy power possibilities and if you truly dont lose any revs, I dont understand any reason to not go with an RB30 over a stroked RB26 for the same price.

Of course I may have a narrow minded view and that is why I wanted to ask you guys here.

If it costs the same to build a stroked RB26 and for a new fully built RB30, why not buy the RB30?

Thanks guys.

-Sayajin

[Alf]

You can still rev an RB30 to 9500rpm and such safely.

The general rule for a Rb30 bottom end is that its limited to approx 7500rpm.

Edited February 8, 2007 by Alf

[Sayajin]

The general rule for a Rb30 bottom end is that its limited to approx 7500rpm.

Which is what I thought as well... however per Ripps Mods,

We're running our forged RB30's up to and over 8500rpm now and they are still pulling hard and smooth, I prefere to give conservitive rev limits to customers although similar internal engines I know of regularly pull 9000rpm+ and 1000hp+ so its up to the individual I suppose.

When you can make over 700whp by 7000rpm with huge torque I prefere to keep the rpm down a bit for long life, its rpm that kills, not outright power.

This made me do a complete double take on my build..... 8500RPM AND an RB30? Why the hell not?

-Sayajin

[R31Nismoid]

I hope you are a rich man

As basically thats all your question requires, money.

Money = revs, if thats what you want.

[Sayajin]

Well... I mean based upon what I was hearing from RIPS, what I was planning to spend to build the crap out of my RB26 and stroke it to a 2.8L is about the same as what I would spend on an RB30.

That is really where my question lies. Of course I dont expect to be able to rev an RB30 to the same place as a 26. However if I can still rev to 8500 safely on the RB30, it would be worthwhile for me personally.

-Sayajin

[R31Nismoid]

Yeah, if you spend the money on it you'll get it to 8500 without much of an issue.

Thats pretty much the answer

[Sayajin]

Got ya... so a normal fully built RB30 is safe to rev to about 7500?

-Sayajin

[r33_racer]

yes..we take ours to 8k...we were worried about the oil pump previously but if you ran an external pump then you can probably rev is further without much concern at all. But most people will tell you there is no need to rev it because it makes the same power as a 25 or 26 at lower rpm, but if you can afford and it still makes strong power upto the rpm limit you want then why not.

[R32 Driver]

anyone got a rough idea on how much it would cost to build a rb30 that will rev to 8000-8500rpm safely?

sounds interesting though i was keen on a tomei 2.8 stroker b4

[Sayajin]

Well I am talking to Rob @ RIPPS as we speak. I plan to find out. I will be sure to relay the info.

-Sayajin

[blk180]

You live in the US of A go buy a crower strocker kit about the same as a tomei price wise but you get a billet crank. They could probly make you a kit for the RB30 then you could rev the crap out of that too. They can also build a 86*86 stroke*bore get a 20mm spacer and some bore liners and you have a home made OS 3lt kit lol.

[Duncan]

I've never understood the "I want to stroke my rb26 so it still revs since an rb30 can't" point of view.

It is primarily the length of the stroke that governs revs (head issues aside). The only real diffference between a 26, 28 and 30 is stroke length. Oh and you pay $5k more for a 28 crank than you would for a larger 30 crank.

Why do people build rb26s? No idea - the only issue with rb30 is the 4wd sump adapter and there are no oil squirters in the block. And rb30 cranks and blocks are significantly cheaper than rb26 ones.

[rsx84]

Why do people build rb26s? No idea - the only issue with rb30 is the 4wd sump adapter and there are no oil squirters in the block. And rb30 cranks and blocks are significantly cheaper than rb26 ones.

i think the VL turbo blocks have the oil squirters in them?

[Cubes]

i think the VL turbo blocks have the oil squirters in them?

Nope.

-----

There's a few RB30's floating around now that rev plenty hard. If you want a hard reving rb26 you have to do the same mods as you do to an rb30.

r33racer rb25/30 I think his alias is... Plenum, exhaust manifold, ext gate, 256 tomei cams and it full spool in the mid 3000's makes power to 8500rpm no problems. 370rwkw I believe it ended up making.

Then there's Bu5ters and a string of VL's.

An RB30 is a hell of a lot cheaper to build than a stroked Rb26.

How many rev's do you want and how often do you want to rebuilt it?

Remember back to the Gibson motorsport bathurst days... They rev limited their Rb26 to 7000rpm for a damn good reason. Longevity.

You also must remember large turbo's need cubes to get them going hard in the lower (less load) gears.

Not much fun if you have to wait until the end of second until things start really happening.

[VB-]

5k for built RB30

15k for built RB26, i know what i'd be doing

note: price may not be 100% accurate, or even close for that matter... lol

[rsx84]

5k for built RB30

15k for built RB26, i know what i'd be doing

note: price may not be 100% accurate, or even close for that matter... lol

a mate was telling me about a place he came across that offered rb30 single cam turbo engines that would rev to 10,000 all day every day, he also mentioned for just the engine your looking at $19,000 no turbo, so anything is possible if you have stupid money

[R31Nismoid]

5k for built RB30

15k for built RB26, i know what i'd be doing

note: price may not be 100% accurate, or even close for that matter... lol

Not sure where you have your prices mate, but they are horridly wrong.

Why even post if you dont know... kinda pointless

[StockyMcStock]

the rev issues with RB30's appears to be that around the 7500rpm mark (standard crank, mains cap, sump, block, oil pump) the system hits a harmonic which essentially distorts the geometry of the whole lot and means you break things. there are a number of ways around this, all things being equal:

1) billet mains cap

2) change the sump to something else - stronger, stiffer

3) dry sump it

4) forged, lighter rods and pistons with crank counterweight lightening

5) billet crank

6) block stiffening (grout filling, girdles etc)

basically the stiffer you can make everything, the higher it will rev. if you can avoid that nasty harmonic (apparently it's very "focal" and if you rev past it quick enough, it goes away above 7500!) then you are in safer territory.

having said that, revs are bad. revs create massive wear on bearings etc, not power. i'm not sure why anybody would want to build an RB26 just so that it can "rev hard". use a bigger capacity engine, fit a larger turbocharger and enjoy the off-boost response. fit taller diff gears to space out the gears and allow the turbo time to work in the first two gears. chasing revs simply for the sake of it is a bad idea.

[r33_racer]

shoosh neill....my dream: an rb30det with to4z 10rpm redline.....words cant express how im feeling right now thinking about that.

See no need to go overboard, something like that is great...but not godlike.

[Adriano]

just curious what people consider big revs for an rb26, i cant see many in australia that need to rev to 10k. To want to rev it this hard, you would have to have a turbo which comes on at 6k, who wants that?