Rb27

[HR31-gts20x]

hey guys

if any can help that would be great

i have a RB25 stock and i have picked up a RB26 crank

now dose it fit in the RB25 block and what bearing do i need to use in it

i will be using RB26 rods and piston to

can wait to here back from you guys thx

[DVS JEZ]

Have a search through the forum. There should be plenty of info on what ur after

[blue_vl_t]

It wont be rb27 though??

[koe]

To build a RB27 using rb26 pistons you will need at leats 87mm pistons.I wouldn't use oem pistons.You can use the rods but.....

The Rod bolts most be replaced.Use arp rod bolts.

Since you will need to get your block bored out make sure you tell the machine shop how much boost you planning on running.

Take the block,crankshaft, Piston ringsand pistons to them and they will gap the piston rings for you to spec.

RB26 crank shaft don't like low gaps in their bearings(rod bearing clearences).

I suguest sticking to 2.1 or above.Nothing more then 2.9 or less then 2.1.

Use high quality rings.The machine shop will tell you which oil you will use.I use conventional non synthetic 10w40.I change my oil with in 1000 miles or after every track day.

The bearings will have to be aftermarket and use calico coating types.

Inspect the crank shaft prior to having it micropolish and balanced to make sure it has a a longer collar drive.

Use arp main and head studs with a MLS based on what type of gas you are planing to run.

Upgrade your oil pump to at least a N1 to improve the oil pressure

get a good oil catch can

and make sure to install the rear main seal the proper way.

after all this the trick is to install good balanced parts that will go on the crank.

Good clutch and a good harmonic balancer.

I suguest you mod the oil sump as well.

Oh and please do a port and polish.To improve the rb25 flow.

The power you make is based on how much air can flow in the cylinder head.Which 25s are restrictive.

Bore size will be based on what would your boost levels be.

So plan on which type of gas you are planning to use.

Up grading your cooling system it's a most.Oil cooler etc.

My compression is a 8.1 but I run nothing but 93 oct all day.

Since I run a 1.8 mls metal gasket(hg). I can't tell you bore size but was set up for 32psi of boost and I run 26psi all day.

Don't worry the machine shop knows which bore size is best for you.

Good luck