1hz turbo camshaft

[roscoFJ73]

Well bugger me, someone in the world got a 1HZT Coaster. It is in the parts book!

They still used the std 1HZ cam though.

Not Sure Where The Coaster Bus Is Sold But I Can Get The Pistons From "engine Australia" For $90.00 Each
?

Engine Australia source their parts from various suppliers,here and overseas.
I would say the 1HZ T pistons are from ACL who make a turbo suitable piston for those who fit aftermarket turbo's.

If you do a search on the net there is no reference to a 1HZ T Coaster anywhere.

This is the other thread where it was discussed recently.https://forum.ih8mud.com/showthread.php?t=168354&highlight=1HZ+COASTER

 

[hdj105]

If you do a search on the net there is no reference to a 1HZ T Coaster anywhere.

This is the other thread where it was discussed recently.https://forum.ih8mud.com/showthread.php?t=168354&highlight=1HZ+COASTER

Just had another quick look, the injection pump for the 1HZ T listing doesn't show a boost compensator on the injection pump either.

My guess is that they were a very limited build for a high altitude application, where the turbo is working more as an altitude compensator.

And if someone wants to do a search, the VIN prefix is "TW043PB50" which I think shows it's not built in Japan...?

 

[roscoFJ73]

My guess is that they were a very limited build for a high altitude application, where the turbo is working more as an altitude compensator.
..?

Why would they do a very limited build when they already have a purpose designed turbo engine in the 1HD T?

 

[drexx]

Just had another quick look, the injection pump for the 1HZ T listing doesn't show a boost compensator on the injection pump either.

Why would they do a very limited build when they already have a purpose designed turbo engine in the 1HD T?

I got an option to put in a 1HD-T injection pump to my 1HZ. Should I do it for more power?

 

[hdj105]

I got an option to put in a 1HD-T injection pump to my 1HZ. Should I do it for more power?

Drexx,

If just for more power I'd suggest no - the standard pump can supply ample fuel to cook the engine

If you required the boost compensator function, then maybe, but even then the pumps are still internally different to suit the 2 different engines.

 

[hdj105]

Why would they do a very limited build when they already have a purpose designed turbo engine in the 1HD T?

Cost, marketing pressure, spare parts availability, local distributor rules (eg. Australia's "3 engine variants per model" policy, etc.

 

[roscoFJ73]

Cost, marketing pressure, spare parts availability, local distributor rules (eg. Australia's "3 engine variants per model" policy, etc.

Those are just red herrings,doesnt explain at all why Toyota would produce 2 turbo 6 cyl diesel engines from a similar variant.

Tell us more about this engine then,and some proof of its existence.

If anything those (non) reasons you gave would be exactly why they would not produce a 1HZ T

 

[roscoFJ73]

I got an option to put in a 1HD-T injection pump to my 1HZ. Should I do it for more power?

Some NZ guy who races a 73 series with a turboed 1HZ runs a 1HD T pump.
He reckons it highly beneficial in HP terms.
Ive forgotten his name but I think he competes in the Outback Challenge

IMO you might as well find a 1HD T if you want the power.

 

[hdj105]

Those are just red herrings,doesnt explain at all why Toyota would produce 2 turbo 6 cyl diesel engines from a similar variant.

Tell us more about this engine then,and some proof of its existence.

If anything those (non) reasons you gave would be exactly why they would not produce a 1HZ T

LOL... Rosco you need to take a pill!!!

I don't know EXACTLY why Toyota would build it, mearly speculating (I haven't worked for Toyota - and I bet you haven't either?).

The fact it's listed black and white in the parts catalogue, and the fact that another member here has purchased the pistons to suit it confirms it exists.

 

[Dougal]

Those are just red herrings,doesnt explain at all why Toyota would produce 2 turbo 6 cyl diesel engines from a similar variant.

I still don't understand why they had both the 1HZ and the 1HD series. Why not make them all direct injection?

 

[roscoFJ73]

The fact it's listed black and white in the parts catalogue, and the fact that another member here has purchased the pistons to suit it confirms it exists.

It maybe listed in a parts catalogue but notice there is no mention of a 1HD T in the same catalogue which makes it seem a misprint.
Also it says it was available in certain markets including Australia,well I havent seen any high altitude Coaster school buses in my area with 1HZ T.
They are all using factory turbos

As I said before ,the 1HZ T pistons are probably the aftermarket type for home brew turbo 1HZ.
I believe they are sold through Repco and Engine Reconditioners Australia not Toyota. (if Repco are selling them its probably ACL who makes them as they are owned by Repco)

What annoys me in these debates is that people go off cockeyed believing such an engine exists when it plainly doesnt
Then you must spend time in the future convincing newbies who are looking for the mythical factory 1HZ T for their transplants that it doesnt exist like the Golden fleece or Elvis's missing HARLEY

Apart from a misprint there is no other evidence it ever existed.

 

[hdj105]

It maybe listed in a parts catalogue but notice there is no mention of a 1HD T in the same catalogue which makes it seem a misprint.
Also it says it was available in certain markets including Australia,well I havent seen any high altitude Coaster school buses in my area with 1HZ T.
They are all using factory turbos

As I said before ,the 1HZ T pistons are probably the aftermarket type for home brew turbo 1HZ.
I believe they are sold through Repco and Engine Reconditioners Australia not Toyota. (if Repco are selling them its probably ACL who makes them as they are owned by Repco)

What annoys me in these debates is that people go off cockeyed believing such an engine exists when it plainly doesnt
Then you must spend time in the future convincing newbies who are looking for the mythical factory 1HZ T for their transplants that it doesnt exist like the Golden fleece or Elvis's missing HARLEY

Apart from a misprint there is no other evidence it ever existed.

OK, so how many misprints do you think they could make on one vehicle?

Firstly a lesson in Toyota model codes, 1990's Coasters are known as HZB30 (when fitted with 1HZ) and HDB30 when fitted with 1HD* engines - this scheme is the same as used for all the other vehicles they manufacture. (eg. HZJ80 vs. HDJ80 vs. FZJ80, etc).

The catalogue only has a listing for HDB30 Coasters up until 01/1993. After that date the Coasters are known as 50 series, eg. HZB50, BB50 (15BFT eng.) now note that there is no listing for a HDB50!!!

Further, when looking into the HZB50R listed with the 1HZ-T, we notice that:-

1. Camshaft is standard 1HZ issue

2. Conrod is 1HD* also shared with HDJ78/79/80/100

3. Pistons are not shared with ANY other application, i.e. unique to the 9301 - 9605 HZB50 Coaster

4. It uses pintle injectors and lists pre-combustion chambers - IDI!

5. Shows exhaust manifold, turbo and crossover (turbo part no. again unique to the 9301 - 9605 HZB50 Coaster

6. Maybe this will convince you - the engine designation decal part number
11291-17020 as per image below - self explanatory really.

A real comedy of misprints wouldn't you think?

 

[roscoFJ73]

Firstly a lesson in Toyota model codes, 1990's Coasters are known as HZB30 (when fitted with 1HZ) and HDB30 when fitted with 1HD* engines - this scheme is the same as used for all the other vehicles they manufacture. (eg. HZJ80 vs. HDJ80 vs. FZJ80, etc).

yeah ,no fawkin s***

OK, so how many misprints do you think they could make on one vehicle?


A real comedy of misprints wouldn't you think?

Yep ,one small mis informed group of people repeating the same mistake through all the earlier literature.
Wherever they mention a 1HZ T ,they omit to mention the 1HD T.
Misprint also says it was sold in ARL market.
ARL is Australia and I wouldnt even waste my time ringing Toyota to see if they have any 1HZ T Coaster parts

Try a search on Google. You can find any legitimate Toyota model for sale or reviewed.....except the fabled 1HZ T powered high altitude Coaster


What you will find in a Google search for a Toyota Coaster HDB50 is a 198 listings including a recall on the brake rotors for all Coasters.
http://dogandlemon.com/site/japanese-vehicle-recalls/?caseno=RJ-0463-0
The HDB50 was made from at least 1993 up until 2001.

 

[cheeckyboy31]

"I still don't understand why they had both the 1HZ and the 1HD series. Why not make them all direct injection?"

as the world falls apart from $4.78 per litre diesel prices (some time in the future) the 1hz and its ability to burn almost anything as fuel will shine like a diamond. low injection pressure and cheap injectors preclude it to be able to run on anything that the fuel pump can survive pushing into them. thats why i think the 1hz is good. In boauganville new ginea, they have made a fuel out of cocanut oil, from what i have been told it does not start very well but once warm it is ok.....also it is cheaper to buy a 1hz than a 1hdt and definately cheaper than the multivalve diesel 1hd-fte i think they call it?? correct me if i am wrong please

 

[cheeckyboy31]

"It maybe listed in a parts catalogue but notice there is no mention of a 1HD T in the same catalogue which makes it seem a misprint.
Also it says it was available in certain markets including Australia,well I havent seen any high altitude Coaster school buses in my area with 1HZ T.
They are all using factory turbos"

the toyota 1hz-t is a factory turbo, the guys at engine australia are very knowledgable and have been most helpfull during the research phase of my engine build up. some of the guys working there have landcruisers so they have a vested interest also.

 

[cheeckyboy31]

"3. Pistons are not shared with ANY other application, i.e. unique to the 9301 - 9605 HZB50 Coaster"


this concurs with what i was told at the shop, engine australia, the combustion relief in the top of the 1hz-t piston (mickey mouse ears) are listed in the tech drawing with a dimension, the std ones are not, we have speculated, as i have not bought the pistons yet that they are larger (wider not deeper), from the picture it looks this way.

 

[cheeckyboy31]

Are you running an EGT gauge?

yes i am, during a long pull through the sand on moreton island towing my dads hilux and campervan i got 550 deg C(in the dump pipe bend after the turbo), saw it and stopped, 3000rpm, heater turned on, no load, it came down very quickly, the engine water temp was maxed out and also returned nice and quick. during normal running including the toowoomba range (uphill) it does not go over 450 deg C.

 

[Dougal]

"I still don't understand why they had both the 1HZ and the 1HD series. Why not make them all direct injection?"

as the world falls apart from $4.78 per litre diesel prices (some time in the future) the 1hz and its ability to burn almost anything as fuel will shine like a diamond. low injection pressure and cheap injectors preclude it to be able to run on anything that the fuel pump can survive pushing into them. thats why i think the 1hz is good. In boauganville new ginea, they have made a fuel out of cocanut oil, from what i have been told it does not start very well but once warm it is ok.....also it is cheaper to buy a 1hz than a 1hdt and definately cheaper than the multivalve diesel 1hd-fte i think they call it?? correct me if i am wrong please

I haven't tried it in my engine. But by all reports other direct injection engines run on vege oil and bio diesel quite well. Does indirect injection have an advantage there?

I understand that the F in 1HD-FTE is four valve, the E is electronic. There is also a 1HD-FT which isn't electronic control.

 

[crushers]

"

the toyota 1hz-t is a factory turbo, the guys at engine australia are very knowledgable and have been most helpfull during the research phase of my engine build up. some of the guys working there have landcruisers so they have a vested interest also.

i am curious, has anoyone ever actually SEEN the factory 1HZ-T engine in real life? if so is the turbo factory equiped or is it an aftermarket turbo installed at the dealer level?

anyone have pictures of this rare beast of an engine? i would love to do a side by side comparrison with a HDT...

cheers

 

[crushers]

the HDT has a different camshaft part number than the HZ and there is no listing for the HZ-T in the EPC.

the same part numbers for the coaster camshaft application. no listing for the HZ-T

the HDT and the HZ have different part numbers but no listing for the infamous HZ-T

the crankshaft for the HDT and the HZ are the same part number but no listing for the HZ-T

i also checked from 1990 to 1999 years just to make sure.

please post up part numbers for this elusive engine code. i would like to run them through the EPC.

cheers