Please tell me about the 1HZ

[Greg H.]

Someone will provide a much better definition than this, but in short it is a Pre combustion chamber.

The diesel partial combusts in the the precup that combustion is what then forces the rest of the fuel air mixture in the the cylinder.

I think......

Tim

So when someone says " Actually 1HZ's seem to drop precups a lot less than 3B's " - What does that mean?

 

[canucksafari]

It means the the precups in the 3B tend to crack and fall into the combustion chamber more often than the precups in a 1HZ. Wanta see what happens? Clicky clicky:https://forum.ih8mud.com/diesel-tech-24-volts-systems/194124-dont-loose-precup-3b-carnage.html

 

[Greg H.]

So it's actualy a seperate part that can come loose, rather than a modification to the head?

Great, now I'm questioning my sanity about geting a Cruiser with a 3B.

 

[canucksafari]

Greg, I wouldn't eliminate a Cruiser with a 3B because of this. It is not a regular occurance like the BEBs on the 1HZ. If the POs have treated the engine well and you do the same, it is unlikely you will have any problems. The 3Bs will easily run well over 500,000 kms. Now if you turbo the motor and run a lot of boost, you are going to reduce its life. Go ahead an turbo it; but be happy with moderate boost and she will treat you fine for a long time.

 

[Greg H.]

Greg, I wouldn't eliminate a Cruiser with a 3B because of this. It is not a regular occurance like the BEBs on the 1HZ. If the POs have treated the engine well and you do the same, it is unlikely you will have any problems. The 3Bs will easily run well over 500,000 kms. Now if you turbo the motor and run a lot of boost, you are going to reduce its life. Go ahead an turbo it; but be happy with moderate boost and she will treat you fine for a long time.

Shoot! It happened again!

And BEB's are?

 

[canucksafari]

"Big End Bearing" See https://forum.ih8mud.com/ca-bc-coastal-cruisers/195318-80s-owners-beaware.html for more info and links.

 

[Greg H.]

Thanks!

If I go to a 1HZ, I'll be sure to have them replaced before it's installed.

Are there other part's issues like the BEB's with the 1HZ?

 

[Dougal]

Some DI are louder but the 1HDT is a very quiet diesel.
I think the lower compression of a DI diesel lends itself better to a turbo as opposed to it's higher compression, precup dropping brethren.

True that DI engines tend to have lower compression. But as soon as you get above the 3 litre mark virtually all diesels are direct injection whether turbo or not. Toyota's 14B is a great example of a direct injection non turbo thats still very quiet. Isuzu DI engines of the same size have a characteristic "grumble" that toyota has managed to avoid.
At the noisiest end of the spectrum, I've spent many thousands of hours behind different perkins 3.152's

 

[roscoFJ73]

So when someone says " Actually 1HZ's seem to drop precups a lot less than 3B's " - What does that mean?

So it's actualy a seperate part that can come loose, rather than a modification to the head?

Great, now I'm questioning my sanity about geting a Cruiser with a 3B.

They fall off after long periods of abuse/neglect and its not a common thing. When it happens,the carnage puts he fear into all owners.
They usually rattle long before they fall off.

Thanks!

If I go to a 1HZ, I'll be sure to have them replaced before it's installed.

Are there other part's issues like the BEB's with the 1HZ?

BEB are not an issue with 1HZ normally although I do have one in my shed with a damaged crank

 

[Tapage]

My biggest question, why didn't they make a non turbo direct injection? I think a 1-HD would have been the cats pajamas.

it's my idea but heavy work engines that are think for many km/miles of use are IDI .. less performance but more long lasting life.

 

[sajidd]

Moved from another thread.

Ok, I am not trying to be labeled a heretic or anything, but I have been hearing quite a bit about the 1HZ - why does it seam like is it some kind of Holy Grail?

I mean I see the specs. and while they appear to be ok ( I wouldn't mind replacing my 3B with one, just because it appears to be a basic no frills engine - but what do I know? ), what makes the 1HZ so special as compared to other Toyoda engines of simular displacement ( maybe I just don't know enough about engines - but I trying to learn ).

Greg H, do you know the turbo that you want to put in 1hz?
I have lc 105 with 1hz and would like to intall a turbo + intercooler,
and would love to know the technical details..

 

[blackknight]

I'll let you in on a little secret - I know first hand what it is like to drive a vehicle that has an engine that relies on a turbo - and have the turbo fail on the hwy - going from 65 mph to perhaps 20 mph ( with the throttle floored ) in about 30 seconds while in the center lane in traffic going through the middle of Portland OR at 4 in the afternoon.

I never want to do that again, and that is why I never bought another vehicle that had an engine that required a turbo.

How do think that influences my thoughts?

Man,
The same has happenned to me in my 2004 Nissan Frontier Turbo diesel....The engine simply shut down on me after making so much noise ,I thought I was dragging it behind me ....That was a real pain.

 

[Dougal]

Man,
The same has happenned to me in my 2004 Nissan Frontier Turbo diesel....The engine simply shut down on me after making so much noise ,I thought I was dragging it behind me ....That was a real pain.

I've also lunched a turbo on a motorway.
First warning I got was the EGT gauge shot past 800 (from 600), then I heard the rumbling, then it lost power.

The big loss of power you get when a turbo dies isn't because the engine relies on the turbo, it's because a turbo that isn't spinning is a big restriction on both intake and exhaust flow.
I was able to pop the clip off the wastegate arm and release the actuator. This let most of the exhaust flow through the wastegate and allowed me a reasonable speed back home (followed by a cloud of blue smoke).
Fitted my backup turbo and was back on the road an hour or so later.

To be honest, I knew there was a chance that turbo would give me the finger, the oil feed line for it came apart a week earlier. I thought I'd tested it enough that it was going to last, but apparently not.