RB20 head mods going to a 2.2/2.3?

[omp]

I am considering rebuilding my RB20 as a RB22/23. Now I know what I need in the block (RB25 crank, rods and 4AGZE pistons). But does any headwork need to be done? What headgasket to use? I could option to O'ring the block and use a copper type gasket this would cost approx. less than $180 for O'ringing (the rebuilder told me he does V8's for $180) and say $200 for the headgasket. Is this what folks do? Any help is appreciated. Oh and how much should I pay for 4AGZE pistons? Also which ones 8:0.1 or 8:9.1? there are 2 types apparently according to toymods. Thanks Pete

[RS500]

hi Pete,

if you're looking at O-ringing the block/head, you can't go wrong with the factory Nissan headgasket.

first of all, what kind of power are u looking at achieving with this engine?

what turbo and more importantly, what kind of boost will u need to run as to get the power you are chasing?

these answers will also affect the compression u need to run in your engine.

if you're not looking at running very high boost (eg, 20+) then, you shluld be able to get away with running 8.9:1, but this would restrict you in case u wanted to aim for higher hp output later on down the track. therefore, 8.0:1 would be perfect for both street driving and at the same time allowing u to run higher boost, if u wanted to.

fyi, opening up the ports on the head, larger lift/duration cams and over sizing the valves will also give u heaps of benefit as the RB20s were a little restricted in these areas from Nissan.

again, it all depends how much power u want to make and how efficiently you want to make it.

[omp]

Hey thanks for the reply! After chatting a bit with sydneykid, he has recommended the 8.9:1. The car is my everyday car, I will probably only run 15psi. The turbo I have is To4/T3, microtech LTX12, bigger injectors, FMIC dual dump, K&N airpod for the engine department.

The engine is getting re-rebuilt and no I am not stuttering. This engine did 2000km's. What the engine builder arsed up

1/miss-aligned cams (both 2-3 teeth) he couldn't diagnose (car idled had no power) so I sent elsewhere I told them it had just been rebuilt, they diagnosed ECU hense microtech. After the car still was not right they found the cam problems.

2/3 standard turbos destroyed before low oil pressure was found to be the problem, cause sealant in the oil pump and pick up. Got GTR N1 oil pump fitted

3/Main bearings upside down, the centre one with the thrust in/on it. effect stuffed crank and bearings is all I hope.

The engine builder at first refused to pay because he said I supplied the bearings (which he fitted and passed). The car went elsewhere where the bearings were found to be upside down. He then backed down and said he would pay for rebuild. His old man got involved (his business) and said crank and bearings only. He said they didn't offer warranty as I was involved with the conversion (fitting fuel pump, thermo's organising loom etc) allthough I had nothing to do with the engine apart from polishing and painting stuff.

A proper engine builder has it now (not just a mechanic but someone who that is all he does is rebuild engines), he said a strip down just to ensure there is no metal etc laying around. The original rebuilders old man refused that, as he looked and saw nothing in the block (um what about the head etc?). My turbo (lucky it is a bushed turbo!) had to be rebuilt as the bearings/bushes got rapped, they were burned and scored.

So far I have spent $6k+ (not including this rebuild) fixing this fella's stuff ups.

That is why I am considering rebuilding the engine this way. It may as of yet get a standard rebuild with just new conrod, mains and headbolts (possibly ARP). I am only checking my avenues. The car before the mains were found, made 252rwhp on 11psi boost.

sorry for the long post....... Pete

[RS500]

that's some bad news u got there Pete.

it's a shame when people stuff something up and don't want to admit it, and in the end people like yourself have to fork out to fix things that should've been done in the first place.

anyway, i'm sure it's gonna get done properly this time and, might i say going for the RB23 stroker is a very good idea.

actually a friend of mine has a R32 GTS-T with an RB24 (RB26 crank & rods), Trust T67 turbo kit which he bought from japan and this thing kicks ass.

he doesn't have a proper ECU on it so he can't get the most out of it, but the potential definitely is there.

good luck dude, i hope all goes well with this build.

let us know how it goes.

[Bl4cK32]

Out of interest can you tell us which of the 4AGZE pistons u found out to use? There are two kinds like you said, but is the choice between the two just effect the compression? Or can you only use one of the two types available??

Very cheap pistons....$100 each for factory forgies roughly....

[RS500]

guys,

fyi, i actually happened to read a zoom magazine last night (older issue) which explained all the different variants of the 4AG engine family.

the reason for the two types of CR with those pistons is that the earlier engines (found in earlier model cars) ran the lower 8.0:1 CR whereas the later engines ran the higher 8.9:1 as to give a little more power and torque.

fyi, bore size and stroke were the same for both engines so u can chose the pistons with the CR that will suit your needs/application.

[Bl4cK32]

cheers dude

[omp]

Here are some links for you, I will be using the 8.9:1 pistons as I think being in the later model 4AGZE's they are probably a better piston.......I think

http://www.club4ag.com/faq%20and%20tech_pa...A-GZE_specs.htm

http://forums.toymods.org.au/index.php?t=m...rt=0#msg_341861

Good luck! Pete

[browny]

One thing I am interested in is where the piston crown will end up in the bore.

I am currently trying to get hold of a stock RB20 rod and piston so I can measure them up and work this out. (Hint hint Bl4cK32 )

[Bl4cK32]

Sorry dude Pm me again and i will remember. Will have a go at it this weekend, so lemme know your details