1hz cracked head

[wayde 75 series]

hey lads
whats the best way to stop a 1hz with turbo from cracking its head

[oldmate]

a 1hz turbo or not won't normally crack a head. you probably have a cooling system problem (water or oil) or are over boosting/fueling.

also i'd be wary of those cheap taiwan heads. if it's got one of them

[wayde 75 series]

its the stock toyota head. perhaps i am runing to much boost its tuned at 14 psi. I was told that was safe with out any extra cooling.

[Kitika]

Mine had 8psi and cracked its head. Precombustion chambers expand and contract at different rates to the rest of the head and make it crack. Well documented and has happened to many 1hz's even stocko engines. And no there is no way to stop it that I could find so I ditched it and learnt to never get a indirect injection again.
Mine has a perfect cooling system the same radiator is keeping my Ls1 cool without any probs with no need for a fan at idle.

[Z()LTAN]

Mine had 8psi and cracked its head. Precombustion chambers expand and contract at different rates to the rest of the head and make it crack. Well documented and has happened to many 1hz's even stocko engines. And no there is no way to stop it that I could find so I ditched it and learnt to never get a indirect injection again.
Mine has a perfect cooling system the same radiator is keeping my Ls1 cool without any probs with no need for a fan at idle.

No offense but its always the same shit from you...


Keep your cooling system in check (fit a more accurate and sensitive temp gauge)
Fit a pyrometer
Keep sustained EGT below 550
Keep boost below 15psi
Service regularly
Use good oil
Intercool it if you can

Do all this and youll be able to keep it for years to come.

I give my 1hz a hell of a time all the time, 25psi, lots of fuel, big cooler, revs to 5000rpm. Driven it like that for a year now and its just as good as it was then.

[SimonInAustralia]

Keep your cooling system in check (fit a more accurate and sensitive temp gauge)
Fit a pyrometer
Keep sustained EGT below 550

...550 C post turbo?

[mickbeny]

Mine had 8psi and cracked its head. Precombustion chambers expand and contract at different rates to the rest of the head and make it crack. Well documented and has happened to many 1hz's even stocko engines. And no there is no way to stop it that I could find so I ditched it and learnt to never get a indirect injection again.
Mine has a perfect cooling system the same radiator is keeping my Ls1 cool without any probs with no need for a fan at idle.

Hi all...Spot on,these engines just cant hack haveing a turbo on long term, driven in the real world,moreso if you use them as a work horse and or tourer with trailer long trips extreme temps up and down the great divide.Another problem is the the top ring grove in the pistons flog out and gets wider due to pistons not ment for turbo.Then you get gearbox problems where they dont live as long as they should.

[T_Diesel]

Mine had 8psi and cracked its head. Precombustion chambers expand and contract at different rates to the rest of the head and make it crack. Well documented and has happened to many 1hz's even stocko engines. And no there is no way to stop it that I could find so I ditched it and learnt to never get a indirect injection again.
Mine has a perfect cooling system the same radiator is keeping my Ls1 cool without any probs with no need for a fan at idle.

No offense but its always the same shit from you...


Keep your cooling system in check (fit a more accurate and sensitive temp gauge)
Fit a pyrometer
Keep sustained EGT below 550
Keep boost below 15psi
Service regularly
Use good oil
Intercool it if you can

Do all this and youll be able to keep it for years to come.

I give my 1hz a hell of a time all the time, 25psi, lots of fuel, big cooler, revs to 5000rpm. Driven it like that for a year now and its just as good as it was then.

x2. There are plenty of turboed 1HZs running around without any issues at all.

The key is maintenance and monitor your temps.

[kingchevy]

1hz are not designed to be turboed..

[Feass]

No, 1hz's are not designed to have a turbo... but they run a shit load better with one. They can also handle them perfectly as well.

x2 to what Zoltan said..

I've had a turbo 1hz for over 100k on mine, starts first time everytime.. no problems at all. and for a 3.1t cruiser, it hauls arse.

I keep my EGT's below 520 post turbo and keep Penrite in it every 5k religiously..

Not all engines are created equal, ive had a mazda astina that missed serviced and was overheated and ran for 520k before it needed a new head gasket.. but still the whole engine was fine..

[thrashlux]

No, 1hz's are not designed to have a turbo... but they run a shit load better with one. They can also handle them perfectly as well.

x2 to what Zoltan said..

I've had a turbo 1hz for over 100k on mine, starts first time everytime.. no problems at all. and for a 3.1t cruiser, it hauls arse.

I keep my EGT's below 520 post turbo and keep Penrite in it every 5k religiously..

Not all engines are created equal, ive had a mazda astina that missed serviced and was overheated and ran for 520k before it needed a new head gasket.. but still the whole engine was fine..

how does changing the oil stop the head cracking????

what does a mazda astina have to do with a diesel 1hz with precom chambers???

[/b]1HZ + turbo = CRACKED HEAD BOOM!!!!!!!!!!!!!

you cannot seee your head cracking or know about it till its cracked all the way and you cant see that till its not bolted on!!!

[Z()LTAN]

same shit, different day....

[thrashlux]

same shit, different day....

yep agreed more young players
ready to learn the hard way
give em a couple of years they to will know the truth

[Z()LTAN]

same shit, different day....

yep agreed more young players
ready to learn the hard way
give em a couple of years they to will know the truth

I have no doubt that my 1hz will give up the ghost one day the way i drive it. Saying that any engine would do the same.

Even if my engine blew up tomorrow it would have still been worth it.

1HZ + decent turbo + 25psi + awesome intercooler = ShortyIQ HELL YEAH!

[thrashlux]

well i have 2 toyota 4.2 diesels in my shed
a 1HZ turbo
a 1HDFTE from 100 series

have a guess which one is in the truck? and which one has got wasp nests in all the bolt holes ?

a clue the one that goes shit loads better and uses less fuel doing it
another clue it has 4 valves per cylinder and direct injection with no precom chambers to crack the head

[Z()LTAN]

Thats all well and good mate

You can have your electrics and computers and immobilizer BS


I have my 1hz that needs 1 wire to run and works 100% submerged underwater..

Nuff said.

[yamaha12]

hahah 1hz yew

[Feass]

Changing oil doesn't stop a head cracking, i didn't say that either. All i'm saying is that preventative maintenance and keep an eye on things will prevent premature cracking of the heads due to turbos. No doubt adding a turbo will decrease the engine life, but if its done properly, it will be a marginal difference.

And in regards to the Astina example. Not all engines are created equal, mate mine has a GQ Patrol that shat itself at 295k, stock 4.2 N/A diesel that had been serviced by a fanatic all its life. Just because you add a turbo, doesn't mean that you're head is going to crack the pre co chamber, there are alot of variables that are involved. As i said, mine runs fine at 220k, and its had a hard 220k.

[Kitika]

Just get a 4.5 have more power than turbo 1hz and won't crack heads readily either.

[oldmate]

Just get a 4.5 have more power than turbo 1hz and won't crack heads readily either.

x2.

then put a turbo charger on that and know what power really is!

[Z()LTAN]

you people are retarded...

Ur missing the whole point.

Petrol is gay

Basic engine dynamics are awesome

If something goes wrong with my 1HZ out in the bush there is a 99% chance i can fix it then and there.

While your there scratching your head with yours ill be back on track.

My turbo 1hz is plenty fast enough... Faster than a 4.5 anyday with less spent on it and a whole cheaper package.

[oldmate]

you people are retarded...

Ur missing the whole point.

Petrol is .

Basic engine dynamics are awesome

If something goes wrong with my 1HZ out in the bush there is a 99% chance i can fix it then and there.

While your there scratching your head with yours ill be back on track.

My turbo 1hz is plenty fast enough... Faster than a 4.5 anyday with less spent on it and a whole cheaper package.

hate to piss on your parade, but when something goes wrong with a 1hz there's no chance you'll be fixing it in the bush. People buy them because they are reliable, not easy to fix

About the only thing you could fix is a clogged fuel line from bad diesel. Even then you'll likely need access to an air compressor, and clean fuel.

[thrashlux]

you people are retarded...


If something goes wrong with my 1HZ out in the bush there is a 99% chance i can fix it then and there.

try fixing a cracked head up cape york
or a stuffed injector pump
both these happend to my 1hz while i had it
it was a POS

with regard to fixing on the track
old timers said the same thing when efi cars came out
how many people do you see driving around with carbies these days
i see a lot less cars broken down these days because of the way stuff works now no mecanical parts to wear or stick

if we were all like you the whole world would be driving around in HQ holdens with a red six in them yeah they are really reliable well people did think so at the time

and you can drive efi diesels under water as long as the water does not reach the top of the dash inside the car
if that is the case the thing is floating down stream anyhow
the engine is water proof it has no hi tension electronics

[Z()LTAN]

You can still drive with a cracked head mate, obviously depends on how bad.

Ive grown up with 1hz powered cars so call me biased but they are great.

Cheap parts, cheap rebuilds, cheap power.

[mickbeny]

Hi all...No doubt about a 1HZ being a great engine.Fair enough,you can get them going with a turbo[like any other engine].But its greatness soon becomes lost when you turbo them.Its like those 3 litter Nissen diesel engines nicknamed the "Hand Grenade"[a fair comparison],Alot of fellas think they are great and others think there shit.It just depends what end of the stick your on with these engines.The same goes with the 1HZ turboed,While the engines going and everythings OK everybody is happy.But when they give up,The feelings become different.
The factory DI turbo engines are just so much better,Not only do they go better they do it with much more reliability.Why waste your money and time on a 1HZ.

[Z()LTAN]

Why waste your money and time on a 1HZ.

Beacuse its still 10grand cheaper than a HDTfte transplant....

[SCANAS]

Yeah that's the killer, price! A conversion with a rebuilt motor and turbo 10k+ and to buy the factory turbo version is more than 10k plus no live axle in 100 series .. There are heaps of charged 1HZ's around, properly set up and used sensibly they will last years.

[skootin]

you people are retarded...


If something goes wrong with my 1HZ out in the bush there is a 99% chance i can fix it then and there.

try fixing a cracked head up cape york
or a stuffed injector pump
both these happend to my 1hz while i had it
it was a POS

with regard to fixing on the track
old timers said the same thing when efi cars came out
how many people do you see driving around with carbies these days
"I do my XD with the 393 stroker has a 950 holley on it. And the 351 in my fj45 has a holley had EFI its to hard to blow fuel into a fuel injector when a fuel pump dies."
i see a lot less cars broken down these days because of the way stuff works now no mecanical parts to wear or stick
""See just as many late model efi cars on the back of tow trucks mate look around.""

if we were all like you the whole world would be driving around in HQ holdens with a red six in them yeah they are really reliable well people did think so at the time

and you can drive efi diesels under water as long as the water does not reach the top of the dash inside the car
if that is the case the thing is floating down stream anyhow
the engine is water proof it has no hi tension electronics


A std 1HZ will crack a head without a turbo the main reason is because people dont maintain the injectors and valve clearance its heat related cracks dont just happen cause the engine is crap. All pre-com chambers will crack they get hot and are glowing 95% of the time the engine is running that heat is then transfered into the cylinder head so if you have a lean cylinder it will get hotter and the rest of the head has to compensate with a turbo you need to be on top of exhaust temps and maintain injectors more often.
Plenty of 1HZ's with over 500 000k's on them i got one and it goes harder then most ive driven even some with turbos. I spent plenty of hours fitting and tuning 1HZ's with turbos if you want anything to survive you have to look after it you must keep an eye on temps and oil pressures dont just pedal it like you stole it. If you stole it you wouldnt be worried bout fixin it when it blows up you just burn it and walk home.
Every engine has a weak link

[Z()LTAN]

well said skootin, but its not lean its rich thats the problem

[flyology]

so if you have a lean cylinder it will get hotter and the rest

Ummm, I think that is wrong, if you have a lean cylinder in a diesel it would be cooler, as more fuel make more heat, less fuel makes less heat.......