As for turbo-ing the HZ, I've seen some forum posts over the internet about head issues once you start putting a turbo on it. Is it true though?
Has anyone done a 1HZ into a KZJ78 body before? Would it fit though since one is 4 cylinder and the other is 6?
I'm not sure how a 6 would fit into a Prado engine bay.
It would it be a costly adventure if you couldn't do it yourself. Time you take into account the cost of finding a 1HZ/1HDT to swap in , you'd be looking at 5K for a HZ in reasonable condition and then proberly near enough that again to get someone to swap it all in. I imagine the radiator ( transcooler if auto) would have to be modified , engine mounts , power steer set up , heater hoses etc etc. It may not seem like alot but having worked in a 4X4 shop for the past 6 months and swapping in a 6 clyinder to my own 70 its amazing how the time adds up
In saying all that. Your old 1KZ could be sold for what 2-3K?
However, recently I saw a few HZJ7- popping up on New Zealand's "eBay" aka TradeMe. I quite liked the look of it and I heard 1hz is the ultimate bulletproof engine. But apparently it's very underpowered and turbo-ing it costs a fortune and decreases the reliability.
What are your thoughts about it? original 1HZ vs original 1KZ.
Also turbo-ed 1HZ vs original 1KZ.
Which one would win in terms of reliability and power?
I've been through this same throught process myself for the past year or so. I had a HZJ70 ( SWB) and like you was on a budget
I wanted it to be turbo'd but after reading a few too many reports about heads cracking that put me off. That & the cost since I couldn't do it myself and would therefore have to pay someone to do it . It wasn't going to be cheap
My next thought was swapping in a 1HD-T from an 80 series.
It was the cheaper alternative than turbo'ing the 1HZ & without the realiability issues but try finding a HD-T in NZ for under 5K ( price I paid for the Cruiser originally)
This all seemed like alot of money just for that added bit of power ( & sound!) I almost ran into what I did by mistake. While browsing trademe one night I came across a old rusty 60 series. 12HT , manual , diff locks front & rear + PTO winch. Okay the engine mounts need to be modified but the gearbox bolts in so your halfway there! I wanted diff locks too so that was that sussed. The PTO winch was just a mega bonus
Now I'm running 12HT with proven realiability , Awesome power & sound . 60 Series diff locking axles which are wider than 70 series ( more stable) and a PTO winch to boot
I'm so wrapped with the set up I'm doing it all again to my other 70
Ultimately what you do depends on your wallet (or) how badly you want your desired Cruiser. Ultimately I think KZ or HZ with HD-T or 12HT swapped in would be a sweet set up. The 12HT's are rare though , that's one thing the HD-T's have over em. Parts etc are easier to find
Ok, any change from what Toyota spent millions of dollars engineering will have an effect. So yes, there will be a decrease in reliability, though negligible.
Unless you're running massive boost on an old dog of a HZ everything should be fine.
Until recently, Toyota has had a habit of over-engineering nearly everything, that's why you see 2H's that go for literally a million klicks on oil + filter changes only. So turboing a healthy 1HZ with a sensible amount of boost would add an almost unmeasurable amount of stress - to the point of saying that it wouldn't decrease reliability.
I agree with what you've said however there appears to be a definate link between people turbo'ing 1HZ's and 'Cracked heads'
Either theres a large number of people out there who've done a bad turbo'ing job or they're just not meant to be turbo'ed. I think I lend towards the latter