Z20 Changeover options

[AndyC]

Hi All. I hope you guys won't feel like I'm here under false pretenses. I have a 1985 Nissan Cabstar light truck (just love it!). It has a carburetted Z20 engine in it ATM. It has a single set of spark plugs ..... not the 8 plug setup that my old Vanette had. It has a four speed gear box. I unfortunately had a major overheating event which has killed the motor (compression escaping bigtime into the cooling system!)

Looking around for a replacement second-hand motor and I'm a bit bewildered by the number of different Nissan engines that all seem to be similar in many ways. I'm not having any joy finding a replacement Z20 and I don't know what other Nissans had the carburetted Z20 motor, the same as this one.

I was wondering if anyone could give me some advice on what my engine options would be ..... i.e. what will bolt straight in where this engine is and what modifications might be necessary if using a different donk. There seem to be fuel injected Z20's, as well as carburetted versions with the 8 spark plug head. And then there are the slightly larger engines that seem to have similar external dimensions.

In short, what can I bolt in as a replacement to my existing motor and what Nissan vehicles would contain those motors? What additional mods will such a change entail (different wiring and electrics.for example)? I see plenty of advertisements for Nissans being wrecked but they always give the vehicle model ... but rarely give info on the engine itself.

Advice from anyone who has actually replaced a Z20 motor with something else would be very much appreciated.

Thanks,

AndyC

 

[Dave]

Welcome mate.

Not good about the engine.

Would you consider EFIing it ?

The KA24E and DE will bolt in.

 

[Dion]

It sounds like you're happy with carburetted engines? If so you'll have no problem swapping in a Z24 - it will bolt in perfectly and all the wiring and lines should plug straight in, provided you source the engine from another two wheel drive vehicle. Your options are the Vanette and the Navara 4x2 from 86 to 94. However, there isn't a Z24 in the world that isn't already on its last legs, these only last 300,000km at worst and 450,000km at very best and they all have that many kilometers being as old as they are. Best bet might be to source a rebuilt exchange engine from a supplier like RPM.

There are other options like newer EFI engines that will match the mounts and bellhousing (KA24DE, KA24E, RB30 if space will allow, etc) but these engines require considerable customisation of wiring and other ancilliaries to work and this doesn't sound like what you're after? For the sake of your research though, at a minimum swapping in an EFI engine will require the addition of an ECU and engine control harness to the vehicle and the splicing of the engine control harness to the necessary components of the main harness, and the adaptation of the accessories such as power steering pump, alternator etc to the old vehicle's wiring and PS lines. More work also if you have air con and more work if you run LPG.

Some 4x2 Navaras had the Z20 and they are often column shift 4spds. There are no Australian delivered fuel-injected Z20 vehicles.

 

[AndyC]

Sincere thanks for taking the time to help me with my query. I really do appreciate it.

My only concern in going the EFI option is simply that I haven't had any experience at doing such a changeover. I can muddle through most mechanical issues (have rebuilt several L20 engines in the past) but I'm afraid I'm a bit "electrically challenged". I don't know anyone who could help me with sorting out the electrics.

It might be that I won't have a choice in the end. I haven't had any joy as yet, in sourcing a replacement carburetted engine. Its only the electrics that are an issue. The vehicle is extremely basic, so no power steering, air con or anything else to muddy the waters.

Anyhow Dave and Dion, just wanted to say thanks for your help.

Cheers,

AndyC

 

[Dave]

Mate there is a D22 service manual in the D22 secion.

It has all wiring diagrams.

Shouldn't be to hard to wire up if you get all the relays etc.