# VG33ET questions



## BeyondBiscuits2 (Jan 18, 2006)

I am thinking about building a VG33ET for my '85 300ZX 2+2, but I've some questions to ask if anyone has some answers. So far my research has answered most, but I'm finding it difficult on a few things. First, I have a line on a complete VG33E from a '98 Pathfinder. Vehicle is totaled (side impact), but engine looks to be in good shape and undamaged. I am also planning on buying a spare VG30E or VG30ET to scavenge parts from (i.e. crank, cams, accessories, intake, etc.). Here are my questions I can't find answers to:

1. Has anyone built a VG33ET using a 30E crank and cams? If so, am I looking at the stock 33E compression ratio of 8.9:1, or the 30E ratio of 9.02:1? I assume the pistons are practically identical, and the only difference in ratio comes from an increased bore. Also, as I plan to swap cams, even if I use a 30E crank, should I find a set of 30ET cams for the more aggressive profile?

2. If a VG33ET has been build from 30E guts, how does it compare to one built from 30ET components? I assume it is similar to a NA2T conversion, but I cannot confirm this.

3. Best turbo combination? I have a line on a T3 manifold from a '84-'86 model, but I can also get the T2 manifold from the '87+. I'd prefer to run a T3/T4 hybrid around 8lbs, but I'd settle for a T28 or T25 at 10-12lbs. I'm not looking for a monster engine here, probably something around 300hp. A colleague has Nistune and can tune the engine, and I am also planning on using Mitsubishi 390cc injectors, being low impedence and readily available. The car already has a Walpro 255lph fuel pump installed.

Before anyone asks, I plan on completely rebuilding the VG33 before I run it. New bearings, engine seals, valve stem seals, heads dipped and decked, etc. I might even splurge and get the heads deburred, who knows! Needless to say, it is going to be a project, and nothing is going to happen overnight. I'd appreciate any input anyone can give!


----------



## jdg (Aug 27, 2009)

And the brakes?


----------



## BeyondBiscuits2 (Jan 18, 2006)

What about the transmission? What about the clutch? What about the flux capacitor? I can ask random questions about random parts too. Come on, it's fun! Seriously, though, brakes are further down the list on things to do. That list also includes rebuilding a transmission, swapping in a limited-slip differential, body work, and finally getting around to putting in my underused and ill-loved cd player, oh, and fixing my leaking heater core.

I'm talking about simply building an engine in my spare time in my garage. This hypothetical VG33ET may never even make it into my car, I might sell it to a friend, or just let it sit until I buy another Z31 in better shape.

P.S. you really didn't even attempt to answer any question I asked. So... why exactly did you feel the need to comment?


----------



## i r teh noobz (Apr 26, 2007)

I just kinda skimmed this page, but I saw references to swapping cranks and such.

XenonZ31 VG33E (t) Motor Swap

The VG30 cams should be the same for NA and T, but they changed from A/B series to W series. 



> Quoted from michaelp on Z31performance.com:
> 
> A/B cams have 4 degrees more duration. These are W-series cams, which are 248/248 dur, .393/.393" lift. A/B are 252/252, .393/.393


----------



## BeyondBiscuits2 (Jan 18, 2006)

Thanks for the link, I seem to recall reading that write-up before, along with TexasAce's. Nevertheless, it never hurts to double check with everything. I did not realise the 30ET and 30E ran the same cams, though. That's good news, as I'll probably just use a 30E crank and cams and be done with it. I had forgotten about the need for the oil filter screw and relief valve, though.


----------



## BeyondBiscuits2 (Jan 18, 2006)

Also, does anyone have a factory Z31 turbo manifold they'd sell? I have a line on one about 120 miles away (still on car with turbo), but I'd prefer one already disassembled as I don't plan on using a stock turbo. I'd be a buyer around the $50 range plus shipping (as that's what the salvage yard wants). I do not have a preference on T3 or T2 style flange; I can make either work.


----------



## i r teh noobz (Apr 26, 2007)

Check z31p?


----------



## BeyondBiscuits2 (Jan 18, 2006)

I posted on their wanted section, so we'll see. I'm in no rush, so it is what it is.


----------



## AZ-ZBum (Nov 21, 2004)

BeyondBiscuits2 said:


> 1. Has anyone built a VG33ET using a 30E crank and cams?


Why would you want to? The less you take apart, the less likely you are to screw something up. I'm not sure there's any advantage to using the 30E crank.


BeyondBiscuits2 said:


> If so, am I looking at the stock 33E compression ratio of 8.9:1, or the 30E ratio of 9.0:1?


Since you'd have to use the 33E pistons, you'd be looking at the 33E compression ratio. 8.9:1


BeyondBiscuits2 said:


> I assume the pistons are practically identical, and the only difference in ratio comes from an increased bore.


Not quite. Obviously the 33 pistons will be larger because of the bore. I believe the dish is different as well. But it doesn't matter since you can't use the 30 pistons anyway.


BeyondBiscuits2 said:


> Also, as I plan to swap cams, even if I use a 30E crank, should I find a set of 30ET cams for the more aggressive profile?


There's no difference between 30E and 30ET cams in the Z31.


BeyondBiscuits2 said:


> 2. If a VG33ET has been build from 30E guts, how does it compare to one built from 30ET components? I assume it is similar to a NA2T conversion, but I cannot confirm this.


IF (and that's a big if) you can use the 30E crank,


BeyondBiscuits2 said:


> 3. Best turbo combination?


Best is subjective. Best for what?


BeyondBiscuits2 said:


> I have a line on a T3 manifold from a '84-'86 model, but I can also get the T2 manifold from the '87+.


87 used the T3 as well. The 88 and 89 models used a T25, not a T2.


BeyondBiscuits2 said:


> I'd prefer to run a T3/T4 hybrid around 8lbs, but I'd settle for a T28 or T25 at 10-12lbs.


Why? Makes little sense to make a smaller turbo work harder (and thus creating more heat) than it would to make a larger turbo barely break a sweat.


BeyondBiscuits2 said:


> I'm not looking for a monster engine here, probably something around 300hp. A colleague has Nistune and can tune the engine, and I am also planning on using Mitsubishi 390cc injectors, being low impedence and readily available. The car already has a Walpro 255lph fuel pump installed.
> 
> Before anyone asks, I plan on completely rebuilding the VG33 before I run it. New bearings, engine seals, valve stem seals, heads dipped and decked, etc. I might even splurge and get the heads deburred, who knows! Needless to say, it is going to be a project, and nothing is going to happen overnight. I'd appreciate any input anyone can give!


IMO, opening up an engine just to open it up is a waste of time, money, and introduces opportunity for disaster. Unless you've rebuilt multiple engines or have someone there who has, you're going to end up with a less than perfect motor. The less you take apart, the less opportunity you have to screw something up.


----------



## BeyondBiscuits2 (Jan 18, 2006)

Thanks for your input. I was wondering about several of these things simply because I couldn't find answers for them. I can't find any documentation of a VG33ET built with a 30E crank, so I'm just hypothesising whether it can be done or not. In regards to the turbos, I was referring to the flange type, as a T25 uses a T2 flange. I've plenty of experience building engines, so it isn't a concern about me tearing them down and building them back up. I only ask about the 30E guts because they are readily available to me, while the 30ET is not.


----------



## AZ-ZBum (Nov 21, 2004)

BeyondBiscuits2 said:


> Thanks for your input. I was wondering about several of these things simply because I couldn't find answers for them. I can't find any documentation of a VG33ET built with a 30E crank, so I'm just hypothesising whether it can be done or not. In regards to the turbos, I was referring to the flange type, as a T25 uses a T2 flange. I've plenty of experience building engines, so it isn't a concern about me tearing them down and building them back up. I only ask about the 30E guts because they are readily available to me, while the 30ET is not.


All Z31s use the same turbo flange on the exhaust manifold. The Z31's T3 and T25s use the standard T3 size. Not sure where you get they were T2 sized. They aren't.

The only "guts" of the VG30 you could potentially use on the VG33 is the crank. 

If you read the link, it seems to think the only difference between the cranks is the snout. I guess the rods of the "W" series VG30 could be used as well as the VG33 is a "W" series motor. But why? There probably isn't any difference. Regardless, you still have to use the VG33 pistons because the VG30 pistons simply won't work.


----------



## BeyondBiscuits2 (Jan 18, 2006)

Update:

I did some further research with a friend who is a Master Tech at Nissan. According to their specs, the VG30E and VG30ET run the exact same crankshaft, at least in the '84-'86 models. That is good news for me, as I can officially use a 30E crank in a VG33ET. Again, the only reason I am researching this is the ample availability of parts VG30Es, as compared to the no availability of VG30ETs.

P.S. I did not realise the T3 and T25 turbochargers in the 300ZXs ran the same flange design. I have more experience with the T25 and T28 on the SR20DET than run a smaller flange design.


----------



## AZ-ZBum (Nov 21, 2004)

There were two crankshafts for the Z31. The A/B series crankshaft and the W series crankshaft. The W series crankshaft has a slightly longer snout. That's the only difference. I would bet money the W series crankshaft for the Z31 is exactly the same profile as the W series crankshaft for the VG33, just with a slightly different snout.

Why the hell are you sooooo hung up on the crankshaft?

And do you not realize there is just zero difference between the VG30E and VG30ET motors in the Z31? Just pistons and some intake accessories.


----------



## attilapo (Jun 15, 2013)

wow long posts.. well i also get something helpful .. from the comments


----------

