RB26 ShortBlock Prep

[Allan74]

Well, short of buying a "RIPS 52 fastener Billet Main Cap and bracing Kit" and praying.....what are some good practices for getting the most out of a standard 05U block without going to an N1, or heaven forbid.....(drumroll..........dun dun dun....) an RRR Block ?

Does this block (05U) benefit from fill ? For a Street Car application ?

I am about to begin the shortblock phase of my project and am 'overbuilding' it a bit, for peace of mind.

Theoretically, I am build the shortblock for 1,000HP (Crank) and 9,500 RPM with the 'weakest link' being the block itself, although I doubt the car will ever see over 600wheel/8,000 RPM.

The cost difference between crap and decent is pretty close at this point (but GOOD is still out of reach for me....lol), so there is no sense in trying to save anymore cash.....lol

The Shortblock Recipe.....
- Standard 05U Block (Early R32, the 'stronger' myth ?)
- Brand New R34 OEM Forged Crankshaft (2007 box date)
- CP Forged Pistons & Moly Rings, 87mm
- Manley Pro Series Turbo Tuff Rods w/ARP2000 Fasteners
- ACL Race Series Bearings
- Brand New (direct from Japan) OEM Main Bolts
- ATI 7" Race Dampener 1000HP
- Everything NEW (cam pulley, balancer bolt etc. USED Block ONLY).

The Variables at this point:
1) If the block needs a line hone, I will buy Main Studs, if not, OEM Bolts will hold fine.
2) I am considering getting the Piston Top's ceramic coated.
3) I am still 'on the fence' in regards to Gapless Rings.....haven't decided.

Feel free to add anything you wish.
Allan

[christ.deyoung]

I read somewhere that you shouldn't run race bearings on a street car, unless you're overhauling more frequently.
I also heard ceramic coated piston tops are excellent.

[mcfly]

you're over working your brain again. OEM bolts will be fine line hone or not, no need to ceramic coat forged piston in a rb, and just use a regular ring pack and some standard gaps.

The ceramic coating cost vs benefit just wont be there. Unless they are free. Our pistons stay pretty cool with the squirters.


Ideally though if you are going to be anal about this you should anti up the 2 grand for a brand new n1 block

[Allan74]

Ideally though if you are going to be anal about this you should anti up the 2 grand for a brand new n1 block

What if I magically showed up somewhere with $10,000 .......wonder if someone would just sell me their built RRR shortblock ?

Seriously though, as it stands, THE BLOCK is the weakest link. If I pony up for an N1 block, where does that move the 'weakest link' to ? THE CRANK ?

[Bignate]

What if I magically showed up somewhere with $10,000 .......wonder if someone would just sell me their built RRR shortblock ?

Seriously though, as it stands, THE BLOCK is the weakest link. If I pony up for an N1 block, where does that move the 'weakest link' to ? THE CRANK ?

The block is not exactly what I would call weak with a 87mm bore. Could always be all baller and sleeve it like mcfly. Shes still a pretty stout chunk of cast iron.

[mcfly]

Even sleeving is questionable as you are digging into factory cast and run through water galleries. mind you they are press fit it might ruin the structural integrity.

regardless of that i did choose to sleeve my block.

[Skym]

The rumour is the first 500 R32GTR's had the R32 Group-A shortblock (homologation reasons). I have seen one of the first 500 GTR's and it doesn't look any different to a stock R32GTR. In reality, I think Group-A shortblock was only for the Group-A specials that Renik / Nismo built for raceteams. Sean Morris at RB Motoring had a photo of a article that showed the outside of one of these Group-A R32GTR's.

From what I understand one of the main weakness with stock shortblock is small watergallery's, which can make shortblock crack around 5th, 6th cylinder which get the hottest (closest to firewall) and affects pistons in those cylinders. Also 5th, 6th cylinder are affected by stock front mount intake plenum design (need to run 5, 6 richer due to getting more air which makes them run leaner / hotter). Hot block (lean A/F ratio, etc) + cool coolant = cracked block. That's why you don't flush shortblock when engine is hot, as it can crack the shortblock.

I have been told that N1 shortblock, N1 head watergallery's have been bored out to solve this problem and Nismo intake plenum has spots for extra injectors on 5th, 6th cylinder, etc. Also N1 shortblock is probably tested for casting, etc flaws. Some mention harmonics play a role.

I think sleeves might help by reducing heat transfer to shortblock thus avoiding hot block, cool coolant problem. They use sleeves on aluminium NA shortblocks (Honda) to increase strength of shortblock when turbocharging engine.

Also they resleeve + spacer plate, etc when going RB30 with RB26 shortblock and handle up to 1500hp.

For example with roughly 1200hp at engine -

http://sthitec.blogspot.com/2009_08_02_archive.html

I think the HT drag R32GTR is running a HKS 2.8 litre version of a sleeved shortblock + spacer plate, etc with 1700hp on Methonal.

You'll wanted coated bearings to reduce cavitation (melting of the surface of bearings under constant hard use). Nismo bearings are coated.

Another option outside Japan is coated Calico beaings (coated ACL, etc bearings) -

http://www.calicocoatings.com/

[Allan74]

The HT R32 is running an RRR block @ 2.6L isn't it ?

[mcfly]

For some reason i heard 2.6 as well.

[Allan74]

Not enough info unfortunately......damn racers and their 'secrets'....lol
http://www.htlracing.co.nz/thecars.htm

[Skym]

As far as I know HKS R33GTR, HT R32GTR have HKS 2.8litre bottomend. HT R32GTR had a JUN head, but last I heard they changed cams for custom cams. Also HT have recently upgraded the turbo, so should be more than 1700hp. You'll notice they have HKS and JUN on side of HT R32GTR. ;)

2.6 litre is Godzilla Motorsport R32GTR in Australia. Red Baron R32GTR in NZ is 2.7 litre.

[Skym]

On the subject of cracked RB26 shortblock.

Photo's of what a cracked RB26 shortblock looks like -

http://2.bp.blogspot.com/_vhpEGyEVhes/RpbIrW-AxzI/AAAAAAAAACE/7epF2ZiE6mk/s1600-h/IMG_0350.JPG

http://3.bp.blogspot.com/_vhpEGyEVhes/RpbIrm-Ax0I/AAAAAAAAACM/FqRPvdxa1is/s1600-h/IMG_0359.JPG

Note crack is near the watergallery.

[Allan74]

Well, as of today (FINALLY), the Shortblock.....well, atleast the Rotating Assembly is SET IN STONE. No going back now ;)

Due to issues with supply, I ended up going with my initial Connecting Rod Choice, which were Manley Turbo Tuff I-Beam Rods (over the BC625+ H-Beam Rods).

I nearly ordered a set of Carrillo Pro Super-A's, but couldn't justify the additional $300 USD over the Manleys, as they were an option when the Manley rods were out of stock. Thanks to getting a 'hookup' directly to Manley, all is well now.

I figure, if the folks at Bushur Racing can sleep at night making 1,000+HP all day long on Turbo Tuff Rods in a 4G63 (250HP/Rod), they will be good enough for my little Rb26 build with headroom to spare.

So, once the Rods get here, my shortblock is ready to go in for machining.

Time to get started on the Cylinder Head........

[mcfly]

endyn, but oh right you are not going for man power anymore allan ;)

I think rods are like cars. A cobalt isn't a corvette and you cant expect it to behave like one nor have the research one has. You get what you pay for with internals in most cases unless its tomei.

But you cannot go wrong with the manley's

[christ.deyoung]

Man power...rofl
What are your plans regarding your head/valvetrain?

[Allan74]

What are your plans regarding your head/valvetrain?
Med-Big Cams, Double Springs, Lotts o' Titanium, Some porting.......and 9,500 RPM.

[Aaron]

Any reason you are going with 87mm bore? Is your block that damaged? The problem with going with an 87mm is your walls are starting to get on the thin side. Look into running 86.5mm if you can.

[mcfly]

87mm is plenty thick enough for anything allan is going to do.

[Aaron]

I guess...

[Allan74]

Any reason you are going with 87mm bore? Is your block that damaged? The problem with going with an 87mm is your walls are starting to get on the thin side. Look into running 86.5mm if you can.

I bought the pistons (and actually another set of cheaper rods) early on in my 'parts collecting frenzy' and also 'blind' without knowing the extent of boring that the spare block that I have in the shop would need. I figured 87mm was a safe gamble. as even if the block was bad in terms of damage, it wouldn't be any worse than needing an 87mm bore.

[Drive*R]

Hey guys,

Quick question as I am new, but what would be the benefit to having say an 87 mm bore as opposed to an 86mm or 86.5 mm bore ?

thanks

- Corey.

[Mold]

Im new here too.

86mm = 2568cc

86.5mm = 2597cc

87mm = 2628cc

As far as how much difference it will make, as far as I know, nothing noticable.

[mcfly]

well 86 = 362.73 cfm @ 8k
86.5 = 366.89 cfm @ 8k
87 = 371.29 @ 8k

now those numbers are using a 100% ve and are of course useless for anything but comparison. but lets say 1.6 cfm to hp for an average non turbo car.

it makes a little difference. It will be multiplied for boosted cars though.

[Drive*R]

Ok, so overboring to say 87mm would help what then ? Throttle response ?

[rb-racer]

i'm interested in making a snappy car. can it be done with an rb?

[mcfly]

that's like asking for a d15 honda to tow a 7000 pound trailer.

You could do it if you went and made a high compression rb26 but keeping turbo it just wont be "snappy". Throttle response will be increased anytime you increase the displacement on a rb engine though. in that regard more power under the curve is what you are after.

[Allan74]

i'm interested in making a snappy car. can it be done with an rb?
The closer to SQUARE you get, the 'snapier' it will be.

RB26 is a terrible platform for that kind of build though, as getting 'square' means shorter rods and rods are about as short as they can get safely at 119.5mm as it is in a 'stroker' kit. I won't bother getting into the rest of the details......

Get an RB30. It's got the deck height to work with, as well as long stroke to start.

[rb-racer]

I dont want to spend as much as the rb30 will cost

[Joeatphr]

If you want a block that is 100% dont put ACL in there. Use Power Enterprise.

Thanks,
Joe

[collector240sx]

Sorry Joe, but thread is 2 years old.....

[Joeatphr]

lmao guess so. Was googling and seen it.

[Terrh]

nothing wrong with the ACL bearings. Or any other bearings really. If your clearances are proper and nothing is out of spec anywhere, OEM bearings are good for a million hp.

[Joeatphr]

OEM is good yes, ACL is never consistent when you get it in a set. The range of clearances you get in one box is just stupid!

[Terrh]

what?

I've built 5 motors now with ACL bearings in them and they've all been exact. Do you have evidence (pictures, etc) of this happening?

[Joeatphr]

i can the next time I do something with ACL. Easy to come up with proof for sure. think im bluffing? haha

[Terrh]

When it comes to cars and the internet, I don't take anyone at their word without proof. Especially when every time I've ever used them I've never had a problem. the range of clearances I've got has been exactly what I've expected, every time.