Blackkers 2630 - Almost Ready, Few Queries.

[Blackkers]

Hey fellas

I've been working towards a twin cam RB30 for a while now.

Last year it was going to go in the R33 GTST as a 25/30 neo however I got sick of having no grip so I bought a GTR.

I bought an R32 with a blown engine and stuck a 2nd hand import Rb26 in for the time being.

I stripped down the blown engine and salvaged the head which underwent a full reco with new valve guides too.

the RB30 block came from an R31 which is supposedly less likely to have had overheating issues.

The engine has been assembled using:

standard Rb30 crank - grub screwed and collar fitted

Forged rods

Nitto +9cc 9:1 pistons designed for the twin cam head 86.5mm

standard head reco'd and machined for MLS gasket

powertune adjustable cam gears (modified genuine nissan items)

RIPS 4wd adapter + standard RB26 sump + tomei baffles - Quaife diff planned before engine install

rear of head breather to sump

oil restricters in the block

cometic MLS gasket 1.2mm

R34 Rb25det neo oil pump - inspected, deburred and mild port job. Same internally as N1 pump but 2nd hand and guaranteed working. Too many N1 pumps have failed in early life

Turbo will be ATR45SAT by hypergear external gate. If in the future I'm looking for more ponies & less response I will change to something along the lines of a BW8374 or PTE6466

manifold TBA

The end figure for static compression came out at 8.65:1; I'm not overly happy about that as I'm planning full time E85 but I guess it leaves headroom for more boost

now to the queries:

I'm fitting the engine in an R32 which is known to have bonnet clearance issues. I will drop the engine down as far as I can by modifying the engine mount brackets. I'm also happy to trim the bonnet reinforcement. Can I use any high mount manifold that was designed for the RB26 or do I need to have one made that sits the turbo lower? The engine should sit between 20-25 mm higher than the standard RB26.

If possible I would like to avoid spacing down the subframe but if it's necessary then so be it.

cam timing: Using the factory RB26 cam backing plate markings where are my cams likely to end up in terms of cam timing? I'm happy to set them up as normal and do some minor adjustments using the cam gears just for the run in tune until the full tune is done

Windage tray: The Rb26 had windage trays, Rb30 girdle doesn't accommodate any windage trays. Any point in drilling, tapping and fitting the 26 trays to the 30 girdle?

any input, help, comments or otherwise is appreciated. This has been the biggest project I've ever pursued so I'm hoping I haven't missed anything!

thanks

Edited May 6, 2015 by Blackkers

[KiwiRS4T]

If you read the oil control thread (or at least the last 10 or so pages) you will note that the back of head fitting is redundant and you need breathers on the sump.

My RB30 came out with low compression ratio and low power. The Hypergear turbo may give you more power but if you can do anything to get your CR to over 9 at least that will definitely help.

I think windage trays in the sump would be good. Although i too have an N1 pump I think their life depends on how hard they are worked. Mine is limited to 7000 - if you are planning on more you may want to revisit the pump.

So are you using the RB26 head or the R32 RB25DET head?

If the latter have you got VCT hooked up? You may find with only 7.8mm lift and low compression you will struggle to make more than the 314awkw I got (although I suspect the Hypergear turbo will do better than my 35/40)

You could e.g. get some higher lift cams without excessive overlap from Kelford Cams as well as some better valve springs.

[XKLABA]

Anything that helps balance the pressure between crankcase and head is a good thing, i run a -16 line from block to back of head

If you can get them to line up then yeah standard marks are fine, the mark on the oil pump is TDC and the marks on the backing plate are for the 26 cams at TDC

Windage trays are nice to have but not necessary, i dont have them and see no ill effects from it

[Blackkers]

low compression and low power does worry me. It's pretty much the opposite of what I wanted to achieve with this engine. I think I'll pull the head and remove 1-1.25mm from the surface of the head after doing some maths to make sure its okay. I'd rather do it now than kick myself later on once the engine is installed and running.

Thanks for the input Bob and Mick.

It's a 26 head with standard cams. Lift is 8.6 in 8.3 ex. Ideally I would like cams in the ~245 degree region with ~10mm lift but the factory cams will do for now.

Okay so as far as cam timing goes; I'll set it up as per usual and then I guess I'll leave it in the hands of the tuner to make adjustments. I was under the impression that when set up with the markings the cam timing ends up retarded slightly

[Ben C34]

With a neo head the can timing ends up 4 degrees out. I imagine it would be the same with the 26 head.

The thing is it's pretty easy to be either advanced or retarded. It's half a tooth.

By facing the head it will reduce the error, making it easier for you to get closer to correct.

[luke gtr]

Get a manifold to suit the 30 bottom end, keep the turbo away from the bonnet.

Also, spacing the subframe isn't as bad as alot of people think.

Drop down to a 0.8mm head gasket to lift comp?

The 26 sump has windage trays above the oil pick up.

If you can get the crank ones on, bonus.

Just so you know, once you go a 30, you won't go back.

Good luck.

[Blackkers]

okay good that's another reason to skim the head. Now that the head is on it's hard to think about removing it!

after running some pretty loose numbers. removing 40 thou or 1mm will bring compression up to about 9.4:1

it will also improve bonnet clearance

edit: luke I didn't see your post til just now, unfortunately I can't use a thinner gasket as the quench is tight as feck already

The reason I don't want to lower the subframe is because I think i can get away without it. It will leave the suspension geo as normal.

I've emailed Kyle at 6boost about the manifold to fit RB30 --> R32 GTR.

Havoc fabrication are also happy to accomodate but they suggested looking at a standard highmount as it might fit and save some coin. (sounds like they don't really want the work hey )

Edited May 6, 2015 by Blackkers

[luke gtr]

I dropped the subframe as i didnt want to cut anything.

I can put my entire career back to original (minus paint) if i wanted.

I have a 6 boost, large frame manifold, with the turbo(gt42) I chose, I'm glad I lowered the subframe.

Is for sale

*wink, wink, nudge, nudge*

[KiwiRS4T]

RB26 head stock cams should be fine. What kind of head gasket are you using? I found with the Tomei one I could remove and replace the head at will (has been off twice).

[GTRPSI]

If you try to fit a larger Tomie oil pump you will need to mod the block by grinding where it hits, being a larger pump with a larger backing plate it hits in one area that needs to be removed.

I used the RB26 windage trays, its simple enough to drill and tap the holes in the right place.

I also used a crank scraper.

Made my own Tomie style baffel plate for the sump and used a gated 9lt sump extension.

[AngryRB]

Quick question, do you guys always assemble the headgaskets dry or do you recommend some copper spray on the gasket in case there are imperfections?

Mainly thinking about when using like a 0.8mm or 1mm, with a stock gasket id be assuming its less important...

[Blackkers]

The gasket is a cometic which is a poofteenth behind the tomei in terms of quality but it will suit my application perfectly. The head is coming off again and will have hopefully 40 thou removed before it goes back on

[luke gtr]

Quick question, do you guys always assemble the headgaskets dry or do you recommend some copper spray on the gasket in case there are imperfections?

Mainly thinking about when using like a 0.8mm or 1mm, with a stock gasket id be assuming its less important...

I use hylomar every time.

Works a treat.

[luke gtr]

The gasket is a cometic which is a poofteenth behind the tomei in terms of quality but it will suit my application perfectly. The head is coming off again and will have hopefully 40 thou removed before it goes back on

also using a cometic.

Have had no problems.

[GTRPSI]

New MLS head gaskets are installed dry.

When reusing one, spray Hylomar on the top and bottom.

[jangles]

6boost manifolds are all to suit a twin cam 30 from memory.

Does not mean it will clear bonnet though.

[Blackkers]

Yep. I've ordered one from Kyle. $1240 delivered isn't out of this world if you consider the lifetime warranty and guarantee that it fits and won't leak. I've been the 'poor man pays twice' before and don't feel like doing it again!

I also asked for the flange to sit 25mm down from the normal position and I need a bit of extra compressor housing clearance. Kyle was good about the extra bits

The ATR45SAT has 0.7 compressor AR

Edited May 9, 2015 by Blackkers

[luke gtr]

They sit very close(pretty much touch)the ac hose.

Be sure to heat wrap it so no damage occurs.

[XKLABA]

The ATR45SAT

these look impressive on a 2.6 can't wait to see how they go on a 3.0

[Blackkers]

They sit very close(pretty much touch)the ac hose.

Be sure to heat wrap it so no damage occurs.

Thanks for the tip luke I'll be sure to do that.

these look impressive on a 2.6 can't wait to see how they go on a 3.0

I can't wait either!

I'm putting the intake back together currently. Cleaning the throttles and scraping gaskets has taken hours today.

remembering where all the vac and coolant hoses go is a nightmare as well!!