Aftermarket turbo's

[supersparky]

We have a 93 Coaster, Aussie compliance with the standard 1HZ motor and 5 speed. It doesn't have enough grunt for my liking as at some point we will be towing a Jimny or a motorbike trailer. I was thinking about getting a turbo fitted and wondered if anyone has done that. I think some of the Landcruisers ran the same motor then went to the 1HZt. I am not looking for a huge horsepower increase just want to improve it a bit and gain some extra torque. Any suggestions?

[T1 Terry]

I think the 1HZ motor suffered heat related head cracking problems and cooling system issues so I'd think carefully about it. Turboglide down here in Russelvale have quite a good reputation, might be worth ringing them and see what they think.

T1 Terry

[Ian + Jan]

Hi Dave,

As Terry said, a 1HZ is as it was built, non turbo. A 1HZT was built specifically as a turbo motor therefore all internals were built for the extra torque. So by upgrading the 1HZ with an aftermarket turbo without any other modifications the motor could suffer.

Suggestion which we have done on several vehicles is to put on extractors. It is minimal cost (compared to changing to turbo) and has given increased performance and economy.
If going that way the suggestion would be minimum 2 1/2" to 3" exhaust system.

Cheers

[supersparky]

I think the 1HZ motor suffered heat related head cracking problems and cooling system issues so I'd think carefully about it. Turboglide down here in Russelvale have quite a good reputation, might be worth ringing them and see what they think.

T1 Terry

T1, That's the sort of thing I feared. Does the 1HZt engine suffer from the same problems? The other alternative was to fit a six speed from the new Coaster, but I don't know about the ratios. What I am really trying to do is close the gap between 2nd and 3rd when climbing a hill, and give it a little more pulling power.

[Hamo]

Does the 1HZt engine suffer from the same problems? .

No such thing!!!!!!!!!!!

A Landcruiser 1hdt or a later model 1hd-ft motor will bolt staight in, Both Turbo motors.
But the cost of 2nd hand motor is not cheap.. ( around $8000 - $10,000 just for the motor)

Bolt a turbo on to a 1hzzzzzzz & you'll turn it into a time bomb.

Hamo

[John M]

What I am really trying to do is close the gap between 2nd and 3rd when climbing a hill, and give it a little more pulling power.

Hi don't know for sure about the Toyota six speed but on doing the homework on the Isuzu box, found that all the ratios were the same with only a .73 (from memory) overdrive added, still had the cut lunch spacing between 3rd and 4th, and 1st is still a dead set bog cog, you have to line it up with two trees to check whether it is in fact moving, the overdrive was of little use except as a down hill gear, to maintain the engine in the economical range of both power and Torque ie. at around 2200 rpm it would be necessary to cruise at around 110 kph plus, so as to have sufficient power to climb the slightest rise or even battle the merest headwind, talking to a couple of owners of Winnebago type motorhomes built on the FSR chassis (with the six speed box) this is in fact their experience.
At the end of all my investigations, in my opinion, the necessary expenditure would not have resulted in sufficient useful gain to warrant the expense. All that was left was to put up with what I had, or replace the whole unit.

[T1 Terry]

Thanks for coming to the rescue there Hamo, buggered if I'd heard of a 1HZT engine but I went searching for the head differences or piston differences between the two but I couldn't exactly find any factory pistons or rods, some after market stuff with mixed reports. Besides adding a splitter box to create an over drive for second to bridge the gap there doesn't seem to be a lot of other options, the engine design is just not strong enough to handle a turbo for long periods.
Maybe a 2 stage boost, 3 psi normally and 7psi for the 2 - 3 shift, but the temptation to use it a lot more may be to great to resist.

[PandJ R away]

David

I have recently had the motor on our 92 ( 1hz) rebuilt and in the process brought it up to IHZT spec. We had the turbo fitted, gearbox recond, fuel and water pump done and a 3" exhaut. Fitted some real guages at the same time so I can tell what is happening. Hopefully I can get the diff changed in the next few weeks.

We have just returned from our first long trip Melb and return. We passed a few other coaster on the hills. The bus is great to drive and I thing towing would be more pleasant.

It was not a cheap exercise. Fortunately insurance paid a large portion of the bill. Gotta love Ken Tame.

I am happy to provide more info if needed or we can meet somewhere and you can have a drive.

John

[Hamo]

Thanks for coming to the rescue there Hamo, buggered if I'd heard of a 1HZT engine but I went searching for the head differences or piston differences between the two but I couldn't exactly find any factory pistons or rods,

1hz head is indirect injection with pre combustion chambers (these are what crack)
1hdt head is direct injection (no precombustion chambers) & 2 valves per clyinder
1hd-ft head is direct injection (no precombustion chambers) & 4 valves per clyinder

The 1hdt & 1hd-ft use the same block & crank as the 1hz but use different conrods & pistions.
But the 1hdt & 1hd-ft both have thier own conrods & pistons (thier not the same).

And all 3 use different injection pumps & injectors.

Anyone who fits a aftermarket turbo to a 1hzzz will be lucky to get 100,000 km out of the motor before it go's BANG.

Sure, Plenty of turbo shops will take your money & fit 1 up.
But the truth is, They dont last long.

Hamo

[noelesky]

Hi
The biggest problem is that under heavy loads they run into main bearing problems, shells spinning in block.
Noel