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Rb30 Block Specs (from Fsm)


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One thing i'll say, is that these 'one off' projects, do end up getting extremely expensive quite quickly, as most of the gear will be custom made or modified, and you'll find urself buying 2 or 3 things over to end up with the right combo.

All in all i cant wait to hear what its gonna sound like, and im sure it'd be an intruiging project :(

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it all sound great but with only 94 octane gas I would be going for 10 or 10.5:1. and definately be looking at much higher lift cam shafts. for a high revving 3 litre NA I would be speding lots of money on the head/cams etc as without a turbo these are going to dictate how much power it makes, and what the engine is like to drive.

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One thing i'll say, is that these 'one off' projects, do end up getting extremely expensive quite quickly, as most of the gear will be custom made or modified, and you'll find urself buying 2 or 3 things over to end up with the right combo.

All in all i cant wait to hear what its gonna sound like, and im sure it'd be an intruiging project :(

well, the only thing i can see getting in the way is having to buy custom pistons, a selection of headgaskets and doing custom head work.

the exhaust is going to be made by myself, and would cost the same or even less than a turbo manifold that is built well. I've got the flanges already.

i dont think the rods will need to be modified, and the belt is still up in the air (as no one has replied to my Gates Powergrip GT2 belt thread with any success stories, all hearsay).

The reason why I'm asking a lot of questions, as you all know (by looking at the board index for the passed day or two) is so that when it's said and done, I don't end up buying 2 or 3 things over again, as you stated. LOL

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it all sound great but with only 94 octane gas I would be going for 10 or 10.5:1. and definately be looking at much higher lift cam shafts. for a high revving 3 litre NA I would be speding lots of money on the head/cams etc as without a turbo these are going to dictate how much power it makes, and what the engine is like to drive.

Indeed.

I want to get the bottom end buttoned up first, then I'll get some more money over the winter to button up the valve train and make some real power with the Wolf V500 unit that i'll hopefully be getting.

and the piston to valve clearance is going to dictate how tall a cam I can use as well, so I'll be looking at that carefully.

I think 11:1 is the safest bet for me, however 10.5:1 isnt a huge decrease in power, but for an N/A, i guess you could say it is.

thanks for the heads up

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Any chance of some videos of this puppy once its going ? maybe some pics as well. Would be good if you could keep us posted on this project.

absolutely. even mid-build =)

i ask that you pay no attention to the Canadian accent (if any), ahead of time :(

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yeah anything over 10:1 will give you a pretty lively 3 litre. but seriously look at much bigger cams. 264/8.7mm will not be near enough to give it some real power up top. especially look for more lift. for a powerfully NA motor that is capable of decent revs it's not uncommon to go up around 300 degree duration and 12mm lift (not saying you would go that far, but you get the idea).

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ohhh no problems.. its just the guys down south that can get annoying at times =)

absolutely. even mid-build =)

i ask that you pay no attention to the Canadian accent (if any), ahead of time :(

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yeah anything over 10:1 will give you a pretty lively 3 litre. but seriously look at much bigger cams. 264/8.7mm will not be near enough to give it some real power up top. especially look for more lift. for a powerfully NA motor that is capable of decent revs it's not uncommon to go up around 300 degree duration and 12mm lift (not saying you would go that far, but you get the idea).

In due time, Baron.

Once I take the head off for it's 6 to 12 month inspection (provided it works as planned) I'll do up the head with some larger valves, stiffer springs, and taller/wider cams.

Then I should make real power.

For now, keeping it mid-range isn't going to dissapoint me. I know there's a lot more to be had in terms of power by doing extensive head work. But I have to take things one step at a time, and these hks cams that I got will allow me to make some money back when I sell them to someone with a mild skyline that they want to upgrade at a later time as well.

Cheers. ;)

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  • 3 weeks later...
  • 4 weeks later...

Hi , I'm unbiased with manufacturers so I'm curious to know a few things .

Firstly is the car going to be a Nissan ie Skyline or is the drawcard having a large capacity RB engine for its own sake .

The reason I ask is that it seems Nissan never intended the RB30 to be a high performance engine so there never was a twin cam head developed for it . I think the greatest limiting factor is going to be getting enough air in and exhaust out even with a modified RB26 head , the 3L brings obvious torque potential being ~ 20% larger but to make power at revs it has to breathe and with only atmo pressure to charge the cylinders I'm not sure if its possible to get enough valve and port area into an RB26 head .

If you have choices there are other alternatives like 2JZ's and BMW etc straight sixes that are probably a bit less compromised than an NA RB2630 . Actually thinking about it if you look at Nissans V6's the bore was larger and the stroke shorter (ie VG30 is I think 83 stroke/87 bore) which in theory gives greater breathing abilities (can fit larger valves in greater sized bores) and the shorter stroke possibly means less piston innertia . The VG30 by todays standards is bulky and heavy and the VQ30's would have some design updates over the old 4 cam twin plenum VG30 . I'm pretty sure a few years back there was some form of VQ30 based competition engine and its results were very good . If it were me I'd research those before I put a lot of resources into a hybrid RB30 - particularly an NA one .

Factory engineering is often hard to beat from a costing point of view so if you can benefit from their R and D so much the better .

More than one way to crack the 3L nut , cheers A .

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  • 4 weeks later...
Hi , I'm unbiased with manufacturers so I'm curious to know a few things .

Firstly is the car going to be a Nissan ie Skyline or is the drawcard having a large capacity RB engine for its own sake .

The reason I ask is that it seems Nissan never intended the RB30 to be a high performance engine so there never was a twin cam head developed for it . I think the greatest limiting factor is going to be getting enough air in and exhaust out even with a modified RB26 head , the 3L brings obvious torque potential being ~ 20% larger but to make power at revs it has to breathe and with only atmo pressure to charge the cylinders I'm not sure if its possible to get enough valve and port area into an RB26 head .

If you have choices there are other alternatives like 2JZ's and BMW etc straight sixes that are probably a bit less compromised than an NA RB2630 . Actually thinking about it if you look at Nissans V6's the bore was larger and the stroke shorter (ie VG30 is I think 83 stroke/87 bore) which in theory gives greater breathing abilities (can fit larger valves in greater sized bores) and the shorter stroke possibly means less piston innertia . The VG30 by todays standards is bulky and heavy and the VQ30's would have some design updates over the old 4 cam twin plenum VG30 . I'm pretty sure a few years back there was some form of VQ30 based competition engine and its results were very good . If it were me I'd research those before I put a lot of resources into a hybrid RB30 - particularly an NA one .

Factory engineering is often hard to beat from a costing point of view so if you can benefit from their R and D so much the better .

More than one way to crack the 3L nut , cheers A .

Good info, but I'm sure you understand when building a fun project is just something you'd like to try. Regardless of it's outcome. Heck, I could always either just increase gasket height or install new pistons down the road, and turbo it again. That's not an issue with me.

And in regard to air intake and exhaust, you're probably right that there are better alternatives. But then again, if I REALLY cared to have the ultimate best for a Z, I would have gotten an LS7 or something and installed corvette C4 suspension all around, and done something like that.

And regarding the bore size, my pistons are 87 mm anyways. It's the stroke that is going to be interesting. The engine is almost square in terms of bore stroke. We'll see what happens.

I just got my engine back from a person who I thought was a machinist, but infact he's just a builder. I'm taking it to a machinist who is closer now, and I'm actually going to start getting things done. All I have to buy is the balancer, flywheel, and bearings, and then I'm ready to start giving the machinist some parts.

Again, I'll keep you guys posted.

I'm just building it to see what I can do with it, that's all to be honest.

And agian, it's not going into a skyline or anything big like that. It's going into a small datsun 280z :)

you guys call em 260z.

Edited by Careless
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