1kz major mods

[benorange]

Has anyone done major mods to these to make them go even better I know about the bolt on bits like manuel pump exaust.
I just brought a motor in bits so have time to up spec it before I put it in.
im thinking bigger pistons or strocker kit but cant find anyone that has done it.
Also head work I was thinking port polish and matching it to manifolds properly as I know with most motors they just get it close.
Bigger turbo? What one?

Any advise would be great and other bits to look at.

[Gyxx]

Hey dude.

The 1KZ was regarded as having very good performance relative to it's displacement when it was first released and when the electronically controlled version came out it gained a few more horsepower. In later model years the inter-cooled version liberated even more ponies and boasted (arguably) improved reliability. Unfortunately the small but powerful (for it's time) 1KZ developed a reputation for having a weak head that was prone to cracking.

If you search these forums and other websites you'll find any number of threads about improving the cooling (and hence the reliability) of these engines but very few on increasing the power output - it just wasn't regarded as an engine that could be reliably modified for more power without blowing it's top. It's also for this reason that so many old Prados which came with the 1KZ or the 2L based engines have formed the basis for some of the great projects you'll find on this forum and other websites - they had good running gear and could be bought cheap because they had blown motors. If you haven't already Have a look at Clint's Cruiser Project for a good example: viewtopic.php?f=18&t=2123

I think most people would say if you've picked up a decent second-hand 1KZ in pieces at a good price; tidy it up, put it back together and good on ya but don't throw money at it. If you're dead keen on extracting some more power from it some people have had joy with some of the mods you've mentioned like manual pumps, bigger turbos sometimes with after-market inter-coolers, power-up chips for the electronically controlled versions etc - as well as doing all the usual cooling mods. Of course all the usual things you can do to any engine to up the power (bigger pistons, sorting out the airflow etc) will work but weighing up the cost versus the improvements versus the reliability just usually doesn't stack up for most people when they start comparing it to re-power with a different engine.

Having said all that I drive a 1KZ myself and have never felt it's under-powered but "I drive like a nana me!". If I wanted to start revving it up and throwing mud around the place though a 1KZ wouldn't be my choice of engine to do it with.

Good luck with whatever you decide to do and if you do something cool post about it on here.

[derk]

good post above ^^^

by all means go for it if you have and want to spend the money on it but don't expect major outcomes for your time and money invested what you'll gain mostly from it is a good learning curve and a hole in your pocket more than performance and reliability, if you want economic performance go and buy a 1UZ or LS1 and throw that in it'll be good bolt in bang for buck

[benorange]

thanks both you. my truck is a 96 kzn185 intercooled. got it cos of the power. ill be doing the rebuild myself so cost is not as big as it would be for some people. I use it as a every day runner so changing to petrol is not an option for me due to running cost. 70km a day.

main reason for building a new motor is so it ready to put in mine as ive got 250k on it now.

when I do things I like them to be a bit difrent more power better looks higher lower all depending on what it is.
im pushind bigger tires and want just that bit more to make it go. it looks like it will be 1mm oversize pistons manuel pump tidy the internals of head and add the big exaust and maybe turbo.

I did a lot of homework befor getting it about looking after it cooling ect so that's all sorted apart from dump pipe and exaust

[lax2wlg]

im pushind bigger tires and want just that bit more to make it go.

Gear it down.
Put the lowest gears you can find in the diffs.
This will enhance the offroad ability a million times more than any engine power mods.

[zed]

I did a lot of homework befor getting it about looking after it cooling ect so that's all sorted apart from dump pipe and exaust

Talk to blakenz on here he did the dump and exhaust for my kzn185 very good product.

[KIWI_TERRANO]

1kz is a good motor

Chick a bigger turbo and manual fuel pump on it, a front mount and water meth injection and the truck will fly

[derk]

1kz is a good motor

Yep they have a fantastic reputation never heard a bad word spoken against them

[KIWI_TERRANO]

Apart from over heating :/ just make sure you maintain cooling system

[stu_71]

Any engine will cook if if doesn't have a well maintained cooling system

[KIWI_TERRANO]

Really didnt know that?!?

But anyway i had a 1kz and rebuilt it twice, they seem to be a bit more prone to it as i also know alot of people who use them as road vehicles with reg servicing and still have issues

[tweake]

im pushind bigger tires and want just that bit more to make it go.

Gear it down.
Put the lowest gears you can find in the diffs.
This will enhance the offroad ability a million times more than any engine power mods.

as above, gearing makes a huge difference. downside can be the onroad driving. may have to make it more efficient in the top end to handle higher cruising rpm without a big fuel penalty.

i'm not sure what the stock injection pump tops out at. electronic control is better and there is products around to enable tuning of it.
basic mods would the turbo and intercooling. matching the turbo is the tricky bit.
also inlet manifold which flows badly in stock form.
oil cooling will help a lot.

[benorange]

im pushind bigger tires and want just that bit more to make it go.

Gear it down.
Put the lowest gears you can find in the diffs.
This will enhance the offroad ability a million times more than any engine power mods.

As I said above I got a motor in parts to do up that why im doing modifiying motor, but will keep that in mind if I turn it full offroader in years to come

[benorange]

I did a lot of homework befor getting it about looking after it cooling ect so that's all sorted apart from dump pipe and exaust

Talk to blakenz on here he did the dump and exhaust for my kzn185 very good product.

thanks will build my own though. ( I like the thought of having as much of my own work on it as possible )

[benorange]

1kz is a good motor

Chick a bigger turbo and manual fuel pump on it, a front mount and water meth injection and the truck will fly

first 2 things prob will happen. What turbo would you use without being stupid big. already intercooled. will look at water meth as know nothing about it thanks

[benorange]

im pushind bigger tires and want just that bit more to make it go.

Gear it down.
Put the lowest gears you can find in the diffs.
This will enhance the offroad ability a million times more than any engine power mods.

as above, gearing makes a huge difference. downside can be the onroad driving. may have to make it more efficient in the top end to handle higher cruising rpm without a big fuel penalty.

i'm not sure what the stock injection pump tops out at. electronic control is better and there is products around to enable tuning of it.
basic mods would the turbo and intercooling. matching the turbo is the tricky bit.
also inlet manifold which flows badly in stock form.

Right about the gearing and fuel.

would you suggest building a custom intake then?
oil cooling will help a lot.

[KIWI_TERRANO]

Ah think kaipoi repowers use a td04 best ringing them re that. Said front mount as not sure what after market turb are like to plumb to factory intercooler

Water meth injection lower intake temp to improve power and fuel burn mix, put on pre turb and one after intercooler just before intake

[tweake]

would you suggest building a custom intake then?

http://www.are.com.au/Inter/4x4%20Plennums.htm
i would sort out the intake. either mod or custom build. that may mean better routing for IC piping to.

water/met injection is good but its something you can add on later.

if your building it yourself, dummy assemble and check the piston protrusion and machine the pistons so the protrusion heights match.

[allys551]

Hey dude.

The 1KZ was regarded as having very good performance relative to it's displacement when it was first released and when the electronically controlled version came out it gained a few more horsepower. In later model years the inter-cooled version liberated even more ponies and boasted (arguably) improved reliability. Unfortunately the small but powerful (for it's time) 1KZ developed a reputation for having a weak head that was prone to cracking.

If you search these forums and other websites you'll find any number of threads about improving the cooling (and hence the reliability) of these engines but very few on increasing the power output - it just wasn't regarded as an engine that could be reliably modified for more power without blowing it's top. It's also for this reason that so many old Prados which came with the 1KZ or the 2L based engines have formed the basis for some of the great projects you'll find on this forum and other websites - they had good running gear and could be bought cheap because they had blown motors. If you haven't already Have a look at Clint's Cruiser Project for a good example: viewtopic.php?f=18&t=2123

I think most people would say if you've picked up a decent second-hand 1KZ in pieces at a good price; tidy it up, put it back together and good on ya but don't throw money at it. If you're dead keen on extracting some more power from it some people have had joy with some of the mods you've mentioned like manual pumps, bigger turbos sometimes with after-market inter-coolers, power-up chips for the electronically controlled versions etc - as well as doing all the usual cooling mods. Of course all the usual things you can do to any engine to up the power (bigger pistons, sorting out the airflow etc) will work but weighing up the cost versus the improvements versus the reliability just usually doesn't stack up for most people when they start comparing it to re-power with a different engine.

Having said all that I drive a 1KZ myself and have never felt it's under-powered but "I drive like a nana me!". If I wanted to start revving it up and throwing mud around the place though a 1KZ wouldn't be my choice of engine to do it with.

Good luck with whatever you decide to do and if you do something cool post about it on here.

I think if you have the cash then go for it. myself i think a CAI/bigger dump pipe & exhaust (straight) /DPCHIP/and maybe an Intercooler would be good. was thinking of a manual fuel pump but seems messy or a bit complicated for me huh. "Diffs" im not sure. i think thats a good balance = performance/fuel economy/cash output.

cheers

[spanky]

the only reason these motors do the heads is because they have not been looked after,we have 6 hiluxes with the 1kz at work and have
never had any trouble,they tow 1000-1200 litre fuel trailers and have done between 200k and 320k km, serviced as the book says from new, we service all our vehicles this way and have no trouble,except for all our new colorados, they are a bucket of shit and all use oil.would not recommend them to anyone.