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I know this has been covered before etc but......

I NEED MORE INFO

I need some one that has either done it them selves or knows some one that has done it and or a tuner that i can call to get more info......

Any help would be great......

Just one more thing i HEARD that using the RB26 crank and rods and i dunno about what pistons but i was told u will get a 2.4ltr and be able to rev to 8500rpm easily is this true?

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https://www.sau.com.au/forums/topic/34629-rb20-to-22-or-24-using-rb26-parts/
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One post only MADGT4 as this has been covered heaps of times and all the info you need is there.

For 2.3 litres

RB26 crank

RB20 main bearings

RB26 rods

RB26 big end bearings

4AGZE pistons and rings

Bronze bush the little end on the RB26 rods to suit the 4AGZE gudgeon pins

Aftermarket oversize RB20DET head gasket

RB26 oil pump

RB26 water pump

Everything else is standard RB20DET, unless you want to upgrade it.

That's it, do a search if you need more.

2.2L thanks to sydneykid in a previous post

sk wrote:

Use the RB25 crank and rods and set of standard 4AGZE pistons, that gives you 2.3 litres. The last set of used 4AGZE pistons I bought cost $100 for the set of 4, so $150 for 6. New set of rings was $20 per piston (AGE's are as common as). Balance all the up & down and round & round bits while you have them out.

Sell the RB25 block and pistons, you'll get most of your money back.

Stick a set of standard GTR camshafts in it (they are cheap), adjustable pulleys and with the right turbo it will fly. I have seen 260 rwkw out of this combo, with a good spread of power across the rev range. Unlike a standard RB20, which at 260 rwkw is very peaky.

Hope that helps

Hi Roy, I'll try and answer a few of your questions...

^ 4AGZE pistons require no machining to fit

^ I believe they are high pressure cast

^ The crown is ceramic coated

^ The skirts are coated with oil retention compound

^ The 4AGZE gudgeon pins fit the little end of the RB25/26 conrods, with very minor machining of the bronze bushes. This is normal stuff.

^ Ceramic coatings is applied to the crown as a heat barrier, it has no effect on the strength of the piston

^ All of the block machining and balancing similar to what you would have to do to make a 2.3 litre RB20 cost me less than $500.

^ Lots of RB30 (Commondoor) parts fit, made by Nissan sold cheap by 'Olden. Think gaskets, seals, water pump, oil pump, bearings etc

So if you can do the engine R&R and the assembly, it will cost less than $5K if you have to buy everything. If you have some of the stuff it will be even cheaper.

But Roy is right, if you have to pay someone to do it, you might as well do an RB31 because it will cost the same. For example a set of 82 mm forged pistons will cost the same as a set of 87.5 mm forged pistons. Balancing an RB30 crank costs the same as balancing an RB25 crank, etc etc.

So as much as I would like to build a 2.4 litre RB20, bottom line is I can build an RB31 for about the same. That's why I haven't done one......yet...

Hope that helps some more

End quote

I hope you don't mind me quoting what you said sydneykid. At least it saves you writing it!!!

I plan on doing this shortly and have the rb25 block lined up, just waiting on my car to get painted and then the engine is coming out to be stroked.

are you shore that the GTR cam will work with the RB20? also what are the spec for the GTR camshafts, also do you happen to know how much the 2.3L can rev up to? and what about engine managment? Thanks

Hi, 93rps13

GTR cams will work, specs are;

--------------------------Inlet--------Exhaust

Timing--------------------240---------236

Lift-----------------------8.58--------8.58

Lobe Centre Angle---------113---------125

I have used 8,500 rpm in both RB20 and RB26, so I see no reason why a combo won't do the same. We use 9,000 rpm + in the 4AGZE, so the pistons aren't going to be a problem.

I use Power FC, you could use a standard R323 GTST ECU and chip it, it will need on line tuning though.

Just to clear something else up, an RB25 crank with standard 4AGZE pistons is called a RB22DET (2.2 litres) and an RB26 crank with standard 4AGZE pistons is called a RB23DET (2.3 litres). You can do an RB24DET by using 1.5 mm oversize 4AGZE forged pistons.

Hope that helps

Tomei also make 2.4 pistons specifically for this type of conversion.

http://www.greenline.jp/catalogue/bcpartli...ntake=FI#engine

at 145,299 Yen or approx Aud $1700 the 4ag pistons are a better buy. Depends on how much you want to spend

I would have loved to do this conversion in my R32 GTST, but i did the math, and bought a R32 GTR instead.

Hi 93RPS13, without a dummy assembly it's a bit hard to guess the compression ratio, on paper it is 8.6 to 1. But that is easily adjusted with a bit of block skimming (for higher) and

bit of combustion chamber releaving (for lower).

You can use any tuning system you like, if it works on an RB20/25 it will work on an RB22/23. How well it will work is another question. My preferences would be real time tuning of the standard R32 ECU for $800'ish or a Power FC for $1,200'ish. Ihave seen SAFC, ITC and VAFC all together on an RB, but by the time you add that up, plus a speed limit defeater, you are way over what a PFC costs.

Hope that helps some more

just a question sydneykid, you said in ur first post you need an aftermarket oversize rb20det head gasket, why is it oversize? i thought the 4agze pistons are the same as the 20det bores, your just changing the stroke right?

Hi jester8686, For 2.2 litres (same as 2.3 litres except you use an RB25 crank and rods, so ;

RB25 crank

RB20 main bearings

RB25 rods

RB25 big end bearings

4AGZE pistons and rings

Bronze bush the little end on the RB25 rods to suit the 4AGZE gudgeon pins

Aftermarket oversize RB20DET head gasket

RB25 oil pump

RB25 water pump

Everything else is standard RB20DET, unless you want to upgrade it.

Hi kwazza11, A4GZE pistons are larger than RB20, if you use RB20 pistons with an RB25 crank you end up at 2.1 litres, hardly worth the trouble.

Hope that helps guys

Hi jester8686, For 2.2 litres (same as 2.3 litres except you use an RB25 crank and rods, so ;

RB25 crank

RB20 main bearings

RB25 rods

RB25 big end bearings

4AGZE pistons and rings

Bronze bush the little end on the RB25 rods to suit the 4AGZE gudgeon pins

Aftermarket oversize RB20DET head gasket

RB25 oil pump

RB25 water pump

Everything else is standard RB20DET, unless you want to upgrade it.

Hi kwazza11, A4GZE pistons are larger than RB20, if you use RB20 pistons with an RB25 crank you end up at 2.1 litres, hardly worth the trouble.

Hope that helps guys

You would also have to search very hard for rods that would fit both for the 2.1 setup correct? I like the small displacement of 2.0 myself, but just figure I'd throw that in since the wristpin for the 2.5 and 2.0 should be significantly different (only dealt with 2.0's myself).

Hi Rbsileighty, you can get Carrillo's off the shelf. Gudgeon pins are 1 mm smaller on the 4 GZE , we use a bronze bush in the rod bored to the correct size. Simple stuff.

Hi kwazza11, boring the block is probably the cheapest part. It has to be honed anyway, so while it is on the machine, it costs very little extra to slip the cutter on. Check the prices, I think you will find it's like $20 extra per cylinder, peanuts compared to the other things you will have to pay for.

Hope that helps some more

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