Twin Turbo 1UZ-FE Swap into 300ZX

8 years ago I built and swapped a twin turbo VG30DE into my 1990 300ZX to replace an NA motor that the car had since factory. I put 45000km on the new engine. It ran great, was tuned very reliably by SpecialtyZ, and was so much fun, but it always had an oil burning issue which was either valve stem seals or turbo seals, and it finally got so bad that I was going to get lung cancer if I left the windows open in the summer, and everyone behind me was choking to death too.

Here’s a picture of the car with its engine from the first swap. It was a resounding success given at the time I had no experience and had never done anything remotely like it before, and it ran very well for 8 years.



Now for something completely different since this particular time in my life is a time of great changes – why not add more changes on top of them.

My friend mentioned one of his dream builds was to put a 1UZ-FE in a 300ZX (he owns a speed shop and will be helping me). Per the 3-second rule of deciding whether or not I should do a particular engine swap, I said “let’s do it.”

Those other changes may be conversations for another day, however, I easily convinced myself to start buying parts for the 1UZ-FE twin turbo swap.

I found this engine at a wrecker (from a 1990 LS400) about an hour away that was missing most of the accessories and the exhaust manifolds, however since I am going to replace most of that anyways, I accepted it at $1000 (which is like, less than $700 USD, lol). I spun the motor by hand and it had some compression and no play, so I think it'll be OK as a rebuildable core.



Here’s a mock up of a 300zx with the 1UZ albeit with quite a bit of jewellery missing.



There’s not a shitload of aftermarket support for the 1UZ-FE compared to other engines, however it’s a somewhat popular swap in New Zealand, Australia and the UK, and there exists multiple options for building a motor such as Kelford camshafts and pistons of various sizes and compression ratios. And, there’s a transmission adapter kit made in South Carolina that will allow me to use my 300ZX transmission which is a nearly brand new ’98 spec, the best one. The comfort of working with a ‘90s Japanese tuner engine is also there, since that’s what I’m most familiar with over the last 10 years of working on cars. The 2nd Gen Tacoma motor is actually very similar to the ‘90s DOHC engines, too.

This ’90 1UZ-FE is the older non-VVTi version, and it literally has no valve timing adjustments at all. The camshafts are completely fixed. So, we’ll have to compensate with more boost. Turbo Kelfords may also be on order. Great news though, the '90-'93 engines had the most overbuilt connecting rods of all the versions of the engines.

Before you ask about costs, I probably won’t tell you what I’m spending on what part or thing – but I’m sure you know just by your own experience, this is not a swap you do if you care about money, or even any other reason other than you have a dumb midlife crisis, or you want to drop even more guys’ boxers at gas stations and car meets. The cost of parts alone required to complete the project is pure obtuseness, and spending the same amount of money on a new VG motor would easily net me a very reliable 800whp.

I hate telling people my power goals, because the law of power goals is: make a goal that you think is way under what you’ll get with the plan in place, and then after you’re done building, get less than whatever your goal was. So I don’t want to look like a fool by making a prediction, but if I can get 450whp and 450wtq plus or minus a bit I’d be pretty happy. A fully built and turbo 1UZ-FE with all the proper breather mods and tunes and custom fabs (and maybe E85 for a tad extra) is allegedly capable of a comfortable 700whp. But, so is any other 4.0L engine I guess.

One big limiting factor is the adapter kit for my 300ZX ’98 spec transmission is not recommended for torque much above 500ftlbs. That allowed me to scale back a few parts – I won’t need new rods, for example. The stock 90-97 1UZFE rods have been proven capable of 500ftlbs and 500whp.

The custom fabrication for this project is going to be epic (at least for me) and that aspect alone will blow that old VG engine away in terms of complexity and car scene cred.

I have a couple of months off work so I’ll be working at my friend’s shop for several weeks tearing down and building up the UZ motor, then in May/June/July we should be able to bang out the swap itself.

A few boxes of parts have already started to trickle in.







So here’s a list of what’s planned.

1. +1mm bore 9:1 forged pistons

2. Ported heads by yours truly

3. Franken-Intake (design tbd) to move the throttle to the center instead of the side where it is on the non-VVTi 1UZ-FE

4. Possible 3UZ-FE throttle retrofit

5. Gen2 GTX 2860 0.84 internal wastegate twin turbochargers by Pulsar Turbos

6. Custom fabbed exhaust manifolds (possibly schedule 10) and downpipes

7. Custom fabbed motor mounts

8. Kelford turbo camshafts

9. A fresh set of valves

10. Link standalone tuned for gasoline, 94 octane

11. Adapter kit for 300ZX 5 speed manual transmission with 500ftlbs clutch

12. 840cc Bosch injectors (stock TT Nissan fuel pump has tons of headroom for the power goals) and 1UZTech billet fuel rails

13. Customize some intercooler piping but reuse some stock 300ZX TT intake piping where possible and reuse side mount intercoolers

14. Remove recirc valves, install blowoff valves

15. Reuse the existing exhaust (an el-cheapo eBay one that actually sounds and flows really good according to the previous tuners)

16. Custom shroud for a mechanical fan

17. New oil pump

18. Remote filter adapter with turbo oil feed attachment

19. Oil cooler (install next year when I start doing the track again)

20. Keep cruise and AC, new fascia or valence on stock facia (although not a priority for this year)

21. A good wire tuck

 

@Torspd
@BassAckwards

I think you guys already follow me on Instagram. I'll be posting a ton of short videos there as I progress. But, for those who come across this, feel free to check out the insta at @ra60f for updates.

 

Subbed

 

What are you planning for suspension?
My neighbor dropped a 347 stroker in his Miata.
It squashed the front end and added a few extra $$$$ to the project.

He's now working on traction issues........

 

That's quite the car there, now THAT would oversteer...

Actually the 1UZ-FE is a bit lighter than the VG30DE! So I'll luck out there. It will improve my weight distribution too.

 

Some more parts today, fuel rails, injectors, filter relocation adapter, timing and gasket kits.

 

Started taking the engine apart today. That's 34 years of dirt right there...

The 3rd picture is the adapter to make my 300ZX transmission work with the 1UZ. It will also adapt to the 350Z and 370Z transmissions. So I can switch to a different transmission at some point if I decide, according to the seller, to make more power.

 

Not too bad... the plugs were good too.

 

That looks really good for the age of that motor.

 

Yeah I think so too, I was expecting more sludge than that for sure.

 

Whoa

 

This is proper OCIs.

 

https://golebysparts.au/search?page=1&q=1uzfe

Got some goodies in there, if you haven't seen those. The oil relocation may be beneficial.

Pretty sure that the guys from www.theskidfactory.com made a custom intake adapter for a Holly intake. Not sure if you've seen that, in one of their YouTube builds. If it helps.

 

Dude thanks for that - there's not a lot online if you do some basic google searches, I found three companies that seem to dominate after market parts, they were good and shipped fast. 1UZTech actually offers a plate like you just described for the intake that fits the Holley - however, my friend wants to weld up a custom fabbed plate and intake. Probably will end up being a similar price and will fit the car better without needing to modify the hood. He's super creative too, and will make it look really unique.

 

I agree, this looks really good, someone definitely cared for this one. Very interested in seeing how everything else looks as you tear into it further

thats a sweet looking adapter plate. Is the factory 300ZX trans a 5spd or 6spd? And will you be keeping the same rear gear ratio?

 

@BartMaster1234 check this out

 

As far as I know, the 300zx was only available in a 5 spd.
My N/A 300 was a 5 spd.

I think the 6 spd came with the 350z