26/30 R34 Gtr **now With Results**

[aphid]

APHID:

what intake manifold are you running? we are going to have issues with the clutch master fouling on the hypertune intake so we are trying to get around that.

we have to run the spacers unfortunetly due to bigger the factory sump we have no clearance to play with.

Yeah I still run the stock intake

[nick81xd]

oh well we cant be that lucky. thanks for the help you might be getting a pm or 3 depending on how nice the car wants to be

Car Update

Should be able to start assembling bottom end thursday arvo, have to put one cylinder together and do some measurements to work out the comp ratio so we can choose appropriate head gasket and if we need to machine some off the tops of pistons.

Head is getting there, getting it back in next day or 2 to finish the port matching and then it can go for final clean and then assembly.

Starting to get to exciting bits of build.

Plan is for a short time from building engine to start up to tuning....then results we are aiming for :D

[GTRNUR]

Your better off not skimming the tops off pistons to achieve the desired deck. You compromise the piston strength and risk upsetting the balance. The last engine saw this done to ended badly with the crown giving way at 8000 RPM. This was followed by the rod seperating from the piston so it could make some holes in the block. It destroyed everything bar the intake and exhaust manifolds.

If you have only had the top of the block leveled to the centerline of the crank, the top of the block will have only been shaved a 5 thou at most. This means that with a 32mm compression height flat top RB30 piston, the crowns will be at most 5 thou positive which is perfectly acceptable.

Don't be afraid to run a positive deck. The closer your crowns are to the quench pads on the head the better the efficiency of the engine. You can safely go as close as about 36 thou, provided you measure everything very very carefully and your main and rod clearences aren't more than about 2.5 thou.

Edited August 30, 2011 by GTRNUR

[nick81xd]

it was a last resort option. Really dont want to mess with pistons thats for sure.

the bottom end was brought with a measured around 10:1 compression so we are looking at anyway to drop that so we can put some boost into it to make use of T51R

[GTRNUR]

The average head after machining comes out between 62-63cc. Call that 63.

An RB30 with the typical RB3025 CP flat tops and a 0 deck and a 1.2mm head gasket has a CR of 8.2:1.

5cc domes gets you 8.8:1.

14cc domes (RB26 size), gets you 10:1.

What pistons have you bought for this project? You either have the wrong pistons and have over-trimmed the deck of the block to achieve a 0 deck, or your maths is a little wonkey...

If you can give me all your dimensions I can plug them into my engine calculator and give you some options if you like?

[nick81xd]

thats what we were told it was, we havent measured it yet as we are waiting for bearings to dummy fit it all to get accurate measurements. Hoping they measured wrong thats for sure

what measurements you need? by end of the week i should be able to get them all.

Pistons im not sure exactly but tim should be able to say that. hope not the wrong ones cause really wanna get a start on engine.

Thanks heaps for your help. Any help we can get is awesome

Edited August 30, 2011 by nick81xd

[GTRNUR]

At a glance you can tell if the pistons are flat tops or domes. If they are dished they are probably RB30ET pistons, and are not suitable for your application.

I've attached a copy of a spreadsheet that will get you 1/2 way there with the calculations. You need to fill in all the red values to produce valid data.

GTR engine-calc.xls

[M.C Ren]

i remember this car for ale a while back, my uncle almot bought it but would have had too many dramas with the top mount and manifold ect being from melbourne, i remember he told me to make up my mind as there wa a guy from queensland wanting to part trade his hsv for it.

what a beautiful car it is though mate, i still have all the pictures he sent to me, just out of curiosity though if you dont mind me asking, how did the engine damage?

becaue i remember it wa a top dollar job at croydon and it didnt have many k's on the rebuild.

either way, nice build thread

[M.C Ren]

damn my s button hehe

[jas/slo32]

The rb30 is running zero deck height.

Pistons are 87mm rb26.

The gtr head has just had a clean up & skim from new.

engine was out of a drag car.

[GTRNUR]

That means your in custom piston terrirory if you want to lower the CR. Its easy enough to sort out though. Just order an RB26 design with the appropriately sized dome to match the CR you want. The spreadsheet above will calculate that for you. Quantum Racing are the people to contact.

Steve Brown

Sales Representative

Quantum Racing Industries

Unit 15, 157 North Road

Woodridge, QLD. 4114

Australia

Ph: +61 (7) 3290-5911 Fax: +61 (7) 3290-5933

Web: www.qri.biz

The alternative and less desirable solution would be to run a 2mm gasket along with deleting one of the quench pads in the head. That would achieve a 9.0-9.2:1 CR, but also creates a slower and less efficent burn in the combustion chamber, along with a poor burn zone in the remaining quench pad area. Fine for high boost, but not good for response or economy.

[mr34 gtr]

i remember this car for ale a while back, my uncle almot bought it but would have had too many dramas with the top mount and manifold ect being from melbourne, i remember he told me to make up my mind as there wa a guy from queensland wanting to part trade his hsv for it.

what a beautiful car it is though mate, i still have all the pictures he sent to me, just out of curiosity though if you dont mind me asking, how did the engine damage?

becaue i remember it wa a top dollar job at croydon and it didnt have many k's on the rebuild.

either way, nice build thread

was nothing to do with the build or croyden it was me being a bit harsh on it.yeah thats me i used my ve clubby as a holding deposit on it.was what i had always wanted so i had to have it.

[M.C Ren]

fair enough, i guess you put the term unbreakable to rest hehe, nice thread, all the best with it

[nick81xd]

UPDATE:.

Block is ready for final assembly after a very light clean up hone of bores from sitting. Crank got polished aswell

All rods have been balanced within 1gram for a smoother engine.

Dummy fitted crank and one cylinder assembly to measure deck height etc to work out compression.

Had 1mm machined off the tops of pistons as it was around 9.5:1 comp and we all know that isnt pump fuel friendly.

Currently deciding which head gasket to go with, we have two options of 8.7:1 or 8.9:1 compression ratios each have pro's and cons.

Need a set of ARP main studs and we can assemble the bottom end finally.

[nick81xd]

FINALLY SOME ACTUAL PROGRESS.

95% of the part we need to finish engine off are here so today got stuck into bottom end.

So good to see some results after so much measuring and planning which hopefully pays off by having a reliable fun engine.

Measured up ring gaps and they were just about perfect for the high performance engine specs so didnt need to ring file them.

Plastigauge the mains and big ends and they were also spot on with advice from engine centre.

ARGO rods and CP pistons

Some building.

Head wrapped up ready to go on. Ported and polished, 280 degree cams, Ferrera valves, JUN valve locks retainers and springs.,...cant wait to hear the lumpy idle again

Cometic 1.8mm head gasket

had to finish off the pick up for the sump adapter mount hole and measure the height it needs to be welding, which is getting done tommorrow.

need some head gasket dowels cause they went missing and finish drilling the oil restrictors then we can put the head on and get to work on accesories fitting.

Then comes another challenge...getting the thing to fit in nicely

[usmair]

http://www.youtube.com/watch?v=srlAJivyqzw

lol i googled jun 2.7 looking for specs and it came up with your car.

there is no other turbo that sounds as good as the t51

[nick81xd]

BOTTOM END OFFICALLY FINISHED

Pre planning and a few minutes of frantic bolt placing and tightening, we managed to get the sump and adapter glued and on. Pretty confident its not going to leak......fun job of cleaning all the excess when it dries sucks though.

Have a hiccup with the oil restrictor for the head not being able to drill through a grub screw sucessfully so we are back to drawing board for the temporarly. Thats all thats holding us up from bolting head on.

Nitto pump full of vasoline to help oil pressure on start up.

Oil pick up welded and bolted down

bottom end closed up hope to never see it again.

PROENGINES sump adapter kit is a awesome kit and suggest it to anyone wanting to do a 4wd RB30 makes life alot easier

[tweety bird]

looks good man.

[methz]

Hope you used enough silicon around the sump wouldn't want it 2 LEAK now !!!!!

[jangles]

BOTTOM END OFFICALLY FINISHED

Pre planning and a few minutes of frantic bolt placing and tightening, we managed to get the sump and adapter glued and on. Pretty confident its not going to leak......fun job of cleaning all the excess when it dries sucks though.

Have a hiccup with the oil restrictor for the head not being able to drill through a grub screw sucessfully so we are back to drawing board for the temporarly. Thats all thats holding us up from bolting head on.

how are you doing it?