5 Cracked pistons

[Roffy88]

Hey guys,
i have just purchased a 79s landcruiser bout 2 months ago, its a diesel 1hz motor with a safari after market turbo, fitted from new. all was going well till the other day, driving up a hill, the motor stopped, then when re started blew white smoke, ive pulled the head off and have seen 4 of the 6 pistons have small fractures through them, and one of them cracked into 3, Which was the third piston, also i think it has cracked off the crank shaft. Just wondering if this has happened to anyone else? or you would know why it would do this? any help would b great. thanks

[84sloth]

sounds to me like it has been getting too high of exhaust temp. caused by overfuelling. check the head for little cracks between chambers also.

[Roffy88]

yer mate cracks between each set of valves and small ones all over the head, so its time for a new head aswell as a rebuild, and the mechanic agreed with you, to much fuel, rekons when they put the turbo on they didnt tune it to suit, just pumped the fuel up. gunna be a pricey effort im thinking. Was thinking bout second hand engine but then you dont know what your getting your hands on there either, could try for one of those 6L chevy diesels? lol bit of fun! any one else got ideas?
cheers

[Shadow]

sounds like someone put a turbo on an engine that wasnt designed for it.

I would be looking for a replacement 1HZ if i was you. They are pretty cheap

[ferrit]

Or scrounge up a 1HD-FTE, they fit straight into a 79 series. Little more pricey than replacing the 1HZ, but infinately better motor

[84sloth]

1hz would be the cheapest option mate. if u were about 3 weeks earlier i had my fully rebuilt 1hz for sale. i wouldnt go for a 1hdfte only because of wiring and all that fuss. 1hdft 24 valve would be my choice no electrics.. but again dear as poison.

[thrashlux]

1hz would be the cheapest option mate. if u were about 3 weeks earlier i had my fully rebuilt 1hz for sale. i wouldnt go for a 1hdfte only because of wiring and all that fuss. 1hdft 24 valve would be my choice no electrics.. but again dear as poison.

not much fuss if you have a loom that plugs in ( i make em to order)
the 1hdfte has better power and fuel economy balance than anything else and it wont blow up

If you do put a 1hz back in leave the turbo off put extractors on and sell the safari kit
other options are 1hdt or as mentioned 1hdft both direct injected unlike the 1hz which was never designed for a turbo

lots of people say 1hz turbo is fine but that is because theirs is still running and they have not looked at the damage inside yet
and when it does finally stop its all too late

[sambo]

do you have any photos

[thrashlux]

Oh i forgot to mention i have a very clean original 1hz for sale it has never been turboed well looked after
it was fine but removed for 1hdfte conversion for a customer as wanted more power
its in brisbane

cheers

jonathan

[oldmate]

lots of people say 1hz turbo is fine but that is because theirs is still running and they have not looked at the damage inside yet
and when it does finally stop its all too late

It's all in the setup and how it's treated. Biggest mistakes people make are overfueling, stonking it off idle/boost (without a boost compensator) and running oversize tyres.

[thrashlux]

could try for one of those 6L chevy diesels? lol bit of fun!
cheers

they have less power and go (even when turboed )than the 1hdfte
they cost more to get in there Due to adapters etc
,are heaver ,gearing is wrong and use more fuel
a lot of coin for going slower and sounding cool :(

[thrashlux]

lots of people say 1hz turbo is fine but that is because theirs is still running and they have not looked at the damage inside yet
and when it does finally stop its all too late

It's all in the setup and how it's treated. Biggest mistakes people make are overfueling, stonking it off idle/boost (without a boost compensator) and running oversize tyres.

thats true....
the trouble its pretty hard to get a decent power increase with out turning up the fuel

so basically if you want to accelerate ,go up long hills ,tow or run big tyres forget it best to leave it alone and make it breath better or get any of the factory turbo's

[oldmate]

thats true....
the trouble its pretty hard to get a decent power increase with out turning up the fuel

so basically if you want to accelerate ,go up long hills ,tow or run big tyres forget it best to leave it alone and make it breath better or get any of the factory turbo's

I think the problems arise when people get power hungry. Sure the FTE is a better motor for power and torque but you can make a 1hz reliable. For starters, stick with 8 pound of boost and run a free flowing exhaust. If you want to tow or run big tyres, look at intercooling and diff gears.
Everything else is just basic maintenance. Don't forget the cooling system, and be religious about 5k oil changes (and preferably less). All that soot that goes out the exhaust is just the soot that didn't go into the oil.



But back on topic, a 1hz rebuild will be around 3.5 grand for parts and machining, minus the labor. So if you aren't doing it yourself than an FTE probably is the answer

[Roffy88]

Thanks for the help guys,
I still havnt sorted out what im going to do yet, as waiting to see what this so calld warranty is going to do for me. (most likely Nothing) If i was to stick with the 1hz, is there anyway of putting stronger pistons and other components in it to help stop the over heating? im in the process of talking to the engine motor rebuilders here.
Any info would be great, as i would like to keep the turbo on the vehicle for that little bit extra power, i run 35 inch tyres and air lockers so would a intercooler help keep the motor cooler?
cheers

[Hamo]

thats true....
the trouble its pretty hard to get a decent power increase with out turning up the fuel

so basically if you want to accelerate ,go up long hills ,tow or run big tyres forget it best to leave it alone and make it breath better or get any of the factory turbo's

I think the problems arise when people get power hungry.

Isn't this why they put the turbo's on in the 1st place.

It doesn't mater what you tell someone who has a 1hZZZZZZZZZZZZ turbo about boost or egt's they all end like this!

[maddog_75]

1hz would be the cheapest option mate. if u were about 3 weeks earlier i had my fully rebuilt 1hz for sale. i wouldnt go for a 1hdfte only because of wiring and all that fuss. 1hdft 24 valve would be my choice no electrics.. but again dear as poison.

not much fuss if you have a loom that plugs in ( i make em to order)
the 1hdfte has better power and fuel economy balance than anything else and it wont blow up

sorry for the thread hijack, but i wanted to ask a question.

do you make plug in looms for a 1hdfte to suit a 75 series landcruiser?

also i guess if you put a 1hdfte into a 75 you'd need to run a computer also and some other sensors?

cheers

[Northside 4x4]

You can reasonably expect 350,000 - 450,000km's out of a Turbocharged 1HZ if tuned conservatively (and thats counting from new)

The pistons may crack sooner or later even with a mild tune as they simply arent designed for the higher pressure and temperature a turbocharger puts the engine through.

Does this mean you shouldnt turbo a 1HZ? Of course not, nothing will last forever and in my opinion your better off enjoying driving your 1HZ 79s for 450,000 rather than putting up with it for 600,000km's.
If you are sensible about it and realistic about the possible torque increase you can achieve with it, it is the most beneficial mod most owners ever make to their 1HZ.

Roffy - Seeing as you obviously have mechanical experience having the head off it already, I will give you a few options.

1) Rebuild the 1HZ with turbo spec pistons and 1HDT rods, regrind on crank, bore and hone block, new rings etc.. & new head. You will probably get away depending on how much work you can do yourself for 3-4K +1-2K for the head

Upgrade to a 1HDT - Substantially more than just 3-4K for the motor, but they are DI so it is a little bit of a step up + you get a boost compensated pump for better tuning.

Upgrade to a 1HDFT - ALOT more, if you can even find a decent motor to slot in there.

As for the chev option. Im not going to bag them to much, but if needed I can provide ALOT of dyno graphs of these motors in either Standard, Supercharged or Turbocharged variants in GU/GQ Patrols and 76/7/9/100s cruiser that will probably put you off owning one. And thats not even mentioning the astronomical cost of the conversion.

[84sloth]

i cant see how a rebuilt turbo 1hz can cost more the a 1hdfte thrashlux. considering the price they are 2nd hand..

[keencdk]

If you do rebuild/replace the 1HZ and put the turbo back on get a decent quality EGT guage. This will give you a realistic view on what is going on in your engine and lets you adjust your driving style. You may find with the tune in your motor it runs cooler EGT's reving its tits off in 3rd gear up a hill rather than cruising in 4th or slogging away at low revs in 5th. Other people with motors set up differently may have a completely different result.

I would put the EGT probe into the exhaust pre-turbo to give you a more realistic reading. You can compensate for temp drop across the turbo when researching what temps are safe but do you really want to guess what is happening in the turbo when you can just go pre-turbo and get a more accurate figure?

There is heaps of info on what maximum EGT's you want in your 1HZ, some are a fair bit higher than others, so work out what the max EGT is you are comfortable with and drive accordingly. I used to figure on 600 pre turbo as the max I would want my EGT's to get to, however I struggled to get to 550 and was happy with the power and go in my HZJ80 with turbo running 10psi. I had a boost compensator fitted and injector pump and injectors rebuilt and tuned and was very happy with the vehicle

[chunderlicious]

so after all this 1HZs cant handle power talk, should i not mention that there is a 280hp 1HZ getting round the gymkhana scene? 300+ kays before it was turbod no internal mods, just pump, intake and turbo... SHIT! i just ruined it for all the haters

[Shadow]

so after all this 1HZs cant handle power talk, should i not mention that there is a 280hp 1HZ getting round the gymkhana scene? 300+ kays before it was turbod no internal mods, just pump, intake and turbo... SHIT! i just ruined it for all the haters

and when it goes bang just like every other turbo'd 1HZ does, you will go "Oh well, it went good for a while"


By the time you install a turbo kit, rebuild your pump and injectors, fit a boost compensator, and an Intercooler.(as someone earlier mentioned he had done) Your cost is likely going to be close to the cost in purchasing a 1HDFTE, or a whole 100series/HDJ79 wreck

And you will have a much better engine with more power in factory spec than the 1HZ will ever give you, and the reliability of an engine built by toyota to be turbocharged, instead of a polished turd just waiting to let you down.

[Northside 4x4]

I doubt there is a 1HZ making 280hp with just a pump and turbo....

Most likely a massive intercooler to drop intake temps to ambient as well.. Even then a picture is worth 1000 words....

Shadow, its no different to a TD42, or 6.5Chev, or 3L Hilux (seriously any motor) That is built with Naturally aspirated power in mind, will go bang one day when subjected to the heat and pressure of a turbo environment....
Tune them right, they will get acceptable k's before any kind of engine trouble.
The alternative is. Dont turbo them and drive up any 5% gradient climb @ 40kph unloaded or 20Kph Loaded?

Rebuild motor $5-6K (maybe 7-8K at a shop with full labour costs, premium parts etc...)
Dont need pump or injector replacement/rebuild (330-400 for recond injectors)
Dont need a compensator (1200 if you did)
Dont need an intercooler (3K if you did)

Look I do probably 1 every 2 months. 80 or 100s from 1HZ blown motor to 1HZ (injector rebuild, engine rebuild to turbo specs, turbocharger, pump with compensator, water to air intercooler, new clutch, few other goodies)
Average cost is around $14,000 drive in drive out. You will not get a 1HD-FT or FTE in the car for less than this and even if you did, it will not make the same power and torque as the 1HZ's I build with custom intercooling and ball bearing turbo systems without spending another 5K+ on the new engine...

[Punchy]

I fitted a complete water cooled turbo and intercooled dts kit to my brothers 100 series myself and has worked and performed faultlessly since doing so.

It tows, it goes to the cape regularly enough and goes on shooting trips out west every second month.

EGT is the key to make power- Cold intake tempratures promote engine longevity.

Some tuners grab a handful of diesel pump and crank in some advance to help with power and EGT and this gets you a bunch a power, but no matter what you do to prevent damge engine life will be decreased either way..

But imho... if i paid 3.5k for a rebuilt donk, stuck a turbo on it, tuned it with an intercooler and flogged the guts out of it for 100-150,000 k - i'd say i got a cheap power up, thats miles in front of a fte or chev transplant for $$$$.

return on investment is what its all about...driving it to and from work and picking up the shopping doesn't count for much tho and is just burning the candle for no real reason. 100k of hard play is what its about !