daisu

Probably your rear shocks then, did you say you are using R32 springs on your cefiro shocks, or R32 shocks/springs. Either way what you have is not setup correctly.

Yeah, I was contemplating just using standard rod/pistons, but as said before I want higher comp. I guess I should start by CC'ing the head and having the block checked first. No point in figuring out I can use X pistons only to find out the block needs to be bored out and the pistons won't fit anymore. I'll just have to go with decked block/shaved head and thin head gasket. I would assume you'd have the block inspected first and then decide if oversize pistons are needed. Or if you had already planned on oversize pistons I guess it wouldn't matter which way you did it. Clarification please?

'Spoolup', do you know how this issue is overcome on the VG30 engines by any chance?

If you had a coolant leak, wouldn't that have shown up in the compression test? Have you pulled the spark plugs out and connected them to the coilpacks to make sure that they are all sparking?

$1500 is still much more than I want to pay when standard items have been proven more than capable in the power range I'm aiming for.

K577M87 - NISSAN RB30 GTR DISH 6577M87 - $852.12 That's US dollars without shipping. And I'm not making anywhere near 530kW. I really don't see the need to use aftermarket pistons in my application. The rods being thinner could be a problem though.

Ah yes, I saw those pistons you had for sale on trademe.nz, question for you, with the pistons you had and using the VG30 rods you said it would give approx 8.3:1 compression ratio. Can I ask what was the compression height of the piston and whether how many CC's if it was dome top or dished? If the VG30E(T) rods have the correct bush size then this would be easier than machining pistons to suit 22mm pin or having bushes made to suit 21mm pin. Only problem is knowing how strong/reliable they are. The factory power output of the engine is very similar to the ratings of the RB30. We'll see if I can find some people pushing decent power through these engines on standard bottom ends.

I see VG30 turbos going a fair bit on trademe and other nz based sites (skylinesdownunder, d1nz etc)

Do some of those tricks include something to make the VCT work, or do you disable the VCT. From what I understood the advantage of using the Z32 ecu was that it was able to be remapped and has VCT function

Direct from their pageAs opposed to picking up a set of VG30 rods/pistons for about $100 and haven't looked at RB25 piston prices but I'm assuming they would be similar priced. Considering alot of people are making good power figures using standard bottom ends in both RB30's, VG30's, and RB25's I don't see the need to upgrade to aftermarket pistons/rods.

Given the options, I'd rather install a longer rod (from an engine that was factory turbo) opposed to decking the block to compensate for the lower height pistons. Also, I'm aiming to get a comp ratio approx 9:1 so I think there would be a fair bit of block decking to reach that with just the 25DET pistons, apparently the galleries start widening once you take off 2mm off the block. From what I've read the VG30 rods fit in the RB30 block/crank, might need to organise something different for the gudeon pins/bearings depending on the piston used. But this all depends on combustion chamber volume, if the block and/or head need shaving to ensure it's true, from the rough calcs I did, the VG30 rods and RB25 pistons could result in compression ratios over 10:1, in which case I may need to use RB26 pistons (lower compression height again). Also, another thing I need to factor is if the block is worn and needs boring out I'll need overbore pistons, which may prove difficult to find 2nd hand. Basically, I see it the similar as using factory RB30 rods and pistons, instead the rod happens to be longer and the piston a bit shorter. The parts are going to be balanced and new bearings etc installed either way and the VG30/RB25 parts can be obtained relatively easily and cheap. Just want to know if it's stupid idea in theory.

Guys, VG30DETT rods are 2mm longer than the RB30 rods. And the RB25DET pistons have the shorter compression height, if I use both of these should give the correct height depending on combustion chamber volumes. Does this sound like a viable option?

Twin turbo manifolds on the VG30DETT, though they have different flange pattern

Have you thought about VG30 turbo? (from the single turbo model obviously). This is a common upgrade for RB20's, would be suitable for RB25 I would think. Failing that, have you thought about purchasing turbo's from Australia?

Rb20 and RB25 exhaust manifolds are the same

R33 turbos aren't expensive, certainly not anywhere near the realm of an aftermarket turbo. And even after you find a problem (if there is one) with the engine, you are still going to have to remove the R32 turbo and replace it with something larger. If anything, the R32 turbo could damage your engine as being undersized it will be running alot less efficiently which equals higher inlet temperatures. Also, since the turbo will be running higher speeds to keep up with the 25 you risk having the turbine on the RB20 turbo failing. RB25 turbo with manifold, dump and lines went for $150 on SD.com forums today. Saw one going on this forum last week for $200. Found one (again this forum) rebuilt for $500. If you are getting aftermarket turbos for this price then they must be cheap copies

I thought IAC and AAC were the same things?

If your pistons are flat top then that means no dome/dish correct? Using the engine compression ratio calculator I'm having to enter values of -1mm deck clearance (piston sitting 1mm above deck at TDC) to get comp ratios of 9:1. Does that sound right to you? Is there a preferred choice in pistons in regards to dome versus compression height? flat tops with higher compression height or domed pistons with lower compression height. I've been looking at other possible sources of pistons, the SR20, 3SGTE, 1J and 2J series engines also share 86mm bore. Is it just a matter of finding something with the same wrist pin diameter? Or can that be overcome with use of different bearings? I'm aiming for somewhere between 250 and 300rwkw, which I think forged pistons are overkill. I'd use the factory RB30 pistons but I want higher compression ratios. Would it be simpler to just deck the block and/or shave the head to remove approx 1mm? Also, ceramic coating the pistons/combustion chambers, is that going to affect the combustion chamber volume or is the amount of change negligible? [/so many questions]

did you replace the spark plugs?

Make: Nissan (duuur) Model: R32 Skyline GTST Milage: approx 160 thou km on the speedo Transmission: Manual Colour: Black Location: Brisbane, Southside Complied? Yeppo RWC supplied? Yeppo Currently registered? Yeppo Price: Looking for $6,500 negotiable, am throwing in some extras to sweeten the deal Contact: Reply here, or PM or msg my mobile 0432 848 627 Comments / Modifications: Basically stock, would suit someone for daily or turning into a slider. It has a catback exhaust, apexi dampener adjustable shocks and lowered springs, adjustable front strut brace (Factory GTR?), slotted front brake rotors, has the 4pot brake calipers, R33 wheels. Also includes the set of standard R32 wheels if you want. Have an M-spec body parts and a blitz turnflow style front mount (uses factory holes in engine bay for piping) that I can also throw in. Rear windows are tinted. Front windscreen and battery are brand new, dash vents are new. The bad parts, The car has had a knock in the rear and there are 2 bits of rust that have cropped up on the rear windscreen. I have multiple quotes to repair the damage ranging from $1600-$2000 I have a new bumper support (reo) and rear bumper that I will include to lower the cost of replacement parts. Also, the clutch isn't great. It is okay for day to day driving (it is currently my daily) but definitely not good for any drifting, but most people would be putting aftermarket clutches in for that anyway. Images:

Yeah, I know how to do it, just more worried that I'm going to be rotating the engine and I don't know how long it's been sitting still for, so I don't want to go turning it over for the sake of a test and end up scoring the bores

What about the exhaust valves? Is there a crank position in which both the inlet and exhaust valves are closed on all cylinders? The engine was sitting under a tarp in a carport when I picked it up, don't know if it had been there the whole time. Spark plugs are in. It does have the whole inlet and throttle still attached and the extractors are still bolted on, so I would guess there would be little chance of things getting in there, except for moisture. I might have a look down the spark plug holes with a torch.

Hey, I've got an RB30E that I'd like to do a leak down test on to get an idea of it's condition before I pull it apart. The engine has been sitting still for who-knows how long (probably over a year), should I be spraying some sort of lubricant into the bores before I turn it over (by hand) to avoid damaging the bores? Or is it not really necessary since it will only be doing 2 or 3 revolutions of the crank.

My vote is sell all your rb26 parts, and use the funds from the 26 to build an RB30DET using your RB25 head.

Here's a pic.. I suppose I could post it, but surely you could find something a bit more local? Let me know if you really want me to post it and I'll see how much freight is going to cost.