Rb29 Wow!

[T04GTR]

Just trying to work out the crank....

from what i gatther its a rb30 crank.. offset ground.

standard 30 stroke is 85mm with a bigend bearing size of 50mm~

this mated with sr20 rods, same bigend as rb25-26 of 48mm~

so.. .5mm offset ground off will reduse the stroke to 84mm with a 49mm size, then ground down to 48mm to suit the sr/rb bearing..

then using the 26 block with 20mm taller liners...

rb26rods are 121mm sr20 rods are 136mm long, rb30 is 151 so the rods are half way in between. (sr20)

that leaves the pistons. asuming they go all the way to the top of the block, with a flat top to give a decent comp ratio. (not to high)

rb30 are A 32mm pin height where 26 are 30mm.

so using 30 pistons would be about right i think.. anyone?

[T04GTR]

oh, ps. it is a great power graph, but it doesnt seem to come on to boost very urgantly. not muck in a fast rize in torque. looks alot like a good v8 curve

[Scotsman]

So when are we putting this in my car ben?

Can we do similar mods to your RB26 builds to get even better low and mid range response?

P.S Don't give this to snowy.

[Swiper the Fox]

Just trying to work out the crank....

from what i gatther its a rb30 crank.. offset ground.

standard 30 stroke is 85mm with a bigend bearing size of 50mm~

this mated with sr20 rods, same bigend as rb25-26 of 48mm~

so.. .5mm offset ground off will reduse the stroke to 84mm with a 49mm size, then ground down to 48mm to suit the sr/rb bearing..

then using the 26 block with 20mm taller liners...

rb26rods are 121mm sr20 rods are 136mm long, rb30 is 151 so the rods are half way in between. (sr20)

that leaves the pistons. asuming they go all the way to the top of the block, with a flat top to give a decent comp ratio. (not to high)

rb30 are A 32mm pin height where 26 are 30mm.

so using 30 pistons would be about right i think.. anyone?

well done Dave...everything else is nearly right...have another think about the crankshaft though.

[adznight]

So when are we putting this in my car ben?

Can we do similar mods to your RB26 builds to get even better low and mid range response?

P.S Don't give this to snowy.

WTF are you doing up @ 1:11am you freak. Go-to-bed

[RPMGTR]

oh, ps. it is a great power graph, but it doesnt seem to come on to boost very urgantly. not muck in a fast rize in torque. looks alot like a good v8 curve

Exactly....it makes 10+psi @ 2500, hence the big torque early.

Some more details:

Crank is a custom billet 12 counterbalance job. Don't try to rev those RB30 cranks too high!

Rods are SR20. Don't sweat the R/S ratio. 1.5-1.65 has proven to be ideal/desirable for a 4 valver in the 1-9000rpm range.

Modern materials and rod/piston designs mean longevity is not an issue, and shorter rod is a stronger,lighter rod.

Pistons are custom.

Camshafts are Nissan OEM.

Turbos are currently Garrett -5's, (about to make way for a very slightly bigger set).

We have now have it tuned at 24lb and it makes 468kw with plenty more through the mid-range.

I'll post a new dynograph when I get a chance.

Lots of sneaky tricks in this one. I probably shouldn't have sold it after all.....

cheers,

[Sydneykid]

Exactly....it makes 10+psi @ 2500, hence the big torque early.

Some more details:

Crank is a custom billet 12 counterbalance job. Don't try to rev those RB30 cranks too high!

Rods are SR20. Don't sweat the R/S ratio. 1.5-1.65 has proven to be ideal/desirable for a 4 valver in the 1-9000rpm range.

Modern materials and rod/piston designs mean longevity is not an issue, and shorter rod is a stronger,lighter rod.

Pistons are custom.

Camshafts are Nissan OEM.

Turbos are currently Garrett -5's, (about to make way for a very slightly bigger set).

We have now have it tuned at 24lb and it makes 468kw with plenty more through the mid-range.

I'll post a new dynograph when I get a chance.

Lots of sneaky tricks in this one. I probably shouldn't have sold it after all.....

cheers,

An SR20 conrod is, what, 136 mm and say the stroke is 85 mm that's 1.60 to 1, which is not so bad, only slightly worse than an RB26 standard. It's the 1.4 of the OS Giken RB30 that would worry me.

Cheers

Gary

[RPMGTR]

An SR20 conrod is, what, 136 mm and say the stroke is 85 mm that's 1.60 to 1, which is not so bad, only slightly worse than an RB26 standard. It's the 1.4 of the OS Giken RB30 that would worry me.

Cheers

Gary

The OS Giken RB30 rod must be a similiar 135ish length to need a spacer plate of around 30mm.

cheers

[Sydneykid]

The OS Giken RB30 rod must be a similiar 135ish length to need a spacer plate of around 30mm.

cheers

The one I dissassembled had nowhere near a 30 mm spacer, it was what OS Giken call a series 1, with the machined spacer plate. The rods were standard RB26 length. The later design has a cast plate, I haven't seen one of them in the flesh, but the plate looks thicker in the photos I have seen.

This is the early kit;

Cheers

Gary

[Roy]

The Trust 2.7L, HKS/Tomei 2.8L and OS Giken 3.0L all get their share of press. However i have only ever seen a demo carrunning the Apexi 2.9L.

I cant read Japanese, but looking at the numbers under pics etc i think the pistons are 87.3mm and use a 22mm gudgeon pin. So what does that make the stroke, about 81mm. Now it uses the std block and some of the text refers to 121.5mm to 118.95mm which i assume refers to the rod length. There is a pic of pistons but i cant make any sense of the numbers.

The demo engine is only using small 250/9.8 cams with an AX70P21 turbo running 1.6bar. The graph is impressive but still very small cc big turbo in shape

[Sydneykid]

The Trust 2.7L, HKS/Tomei 2.8L and OS Giken 3.0L all get their share of press. However i have only ever seen a demo carrunning the Apexi 2.9L.

I cant read Japanese, but looking at the numbers under pics etc i think the pistons are 87.3mm and use a 22mm gudgeon pin. So what does that make the stroke, about 81mm. Now it uses the std block and some of the text refers to 121.5mm to 118.95mm which i assume refers to the rod length. There is a pic of pistons but i cant make any sense of the numbers.

The demo engine is only using small 250/9.8 cams with an AX70P21 turbo running 1.6bar. The graph is impressive but still very small cc big turbo in shape

From memory 121.5 mm is standard RB26 rod length. So the 118.95 may be some (2.55 mm) of the necessary shortening to fit the extra stroke (81 - 73.5 / 2 = 3.65 mm) in the standard block. The remainder 3.65 - 2.55 = 1.1 mm) must come from raising the gudgeon pin height in the piston.

87.3 x 81 = 2910 cc's

118.95 / 81 = 1.47 rod stroke ratio, which I personally think is a fair bit low for reliability and power.

Cheers

Gary

[pepe lopez]

Ben, even though it goes against what you are trying to achieve, what kind of results would you expect by running a big single, say a T88H-38GK on this 2.9 set up. Would there be boost by 4000rpm and would 550-600rwkw be achievable on Shell 100 octane fuel.

[9krpm]

What compression is this engine running?

[Swiper the Fox]

i would have loved a drive.

I went for a drive up Mt Dandenong....its mental!

not as scary as mine as the power delivery is so linear and smooth but all you have to do is look at the speedo every now and then to frighten the life out of you.

Lots of little sneaky tricks on this one that most die hard modifiers would not have even thought of or considered. A mega buck effort thats been done for the sheer love of it and the enjoyment the car has created. In traffic the Vic. HWP didn't even look twice at the car...even when pulled up next to them at the lights as its ultra quiet and idles like a stocker.

Edited January 12, 2009 by DiRTgarage

[N1GTR]

So gets the Paul seal of approval?

[Swiper the Fox]

So gets the Paul seal of approval?

my conversion is now complete

[N1GTR]

Dont tell me you're going stroker now?!?! What happened to "2.6L till i die" or whatever it was

[NYTSKY]

Turbo conversion is complete. Still 26 Steve-o

[N1GTR]

Oh, i see

[Swiper the Fox]

Dont tell me you're going stroker now?!?! What happened to "2.6L till i die" or whatever it was

lol...where did you hear that you Wally?...im sure that was only in your mind.

Im talking about non-obtrusive, quiet, unasuming, but very powerful stock looking and sounding cars. I hate driving my car...even the small distance from the shed to home (and you know how close that is). This car i could have easily driven around in all bloody day.

i didn't throw that RB30 bottom end in the tip to regret it...it was exactly that...rubbish.