hzj73

[coldtaco]

Here is my take on water cooling a IDI turbo'd. This is with my 2H, don't know what kind of results one would get with a HZ. When I first got my truck the boost was set at 8psi. On the drive home from Georgia (4200mi.) climbing some long hills the water temp would reach the top of the gauge before the egt's got too hot. I had no idea numbers wise what temp top of the water gauge is, so I would cool down when ever the needle got close to the top. A couple months after getting home I put a stand alone water temp gauge in and took it for a drive. At 65mph, 65F ambient temp, factory needle about middle the aux water temp showed about 210F. Needles to say I was a bit surprised I can't imagine what the temp would be with the factory needle at the top. So I spent the summer doing everything I could think of to help with the cooling. I flushed multiple times, replaced thermostat with factory and the other brand from Australia with the bigger opening, replaced the radiator core with a staggered 3 core. Also replaced water pump because it started weeping. Nothing helped. So the next spring I was able to get some Evans Waterless coolant from the lower 48 that a friend brought up for me. I put that in with the purpose of at least knowing that I can safely run a bit warmer. Over the winter the upper rad cap kept springing leaks so I started looking for a replacement. I contacted PWR's USA shop and after much back and forth I ordered a custom aluminum rad from them. I had the inlet part lengthened inside the cap to dump about mid point, and I had the radiator extended 2" on the bottom. I also had to replace the Evans because it would jell up in the winter and prevent my Espar from working. So now with the new radiator at hwy speeds 65mph the water sits at about 180F on average and south of town we have a nice 5mi long climb, and when cresting the hill the water would sit at about 193F. I also increased my boost to 12psi and played a little with the fuel. So, my take is if all else fails then maybe a modified radiator would solve your problem. Sorry for the long story.

 

[mike phillips]

Here is my take on water cooling a IDI turbo'd. This is with my 2H, don't know what kind of results one would get with a HZ. When I first got my truck the boost was set at 8psi. On the drive home from Georgia (4200mi.) climbing some long hills the water temp would reach the top of the gauge before the egt's got too hot. I had no idea numbers wise what temp top of the water gauge is, so I would cool down when ever the needle got close to the top. A couple months after getting home I put a stand alone water temp gauge in and took it for a drive. At 65mph, 65F ambient temp, factory needle about middle the aux water temp showed about 210F. Needles to say I was a bit surprised I can't imagine what the temp would be with the factory needle at the top. So I spent the summer doing everything I could think of to help with the cooling. I flushed multiple times, replaced thermostat with factory and the other brand from Australia with the bigger opening, replaced the radiator core with a staggered 3 core. Also replaced water pump because it started weeping. Nothing helped. So the next spring I was able to get some Evans Waterless coolant from the lower 48 that a friend brought up for me. I put that in with the purpose of at least knowing that I can safely run a bit warmer. Over the winter the upper rad cap kept springing leaks so I started looking for a replacement. I contacted PWR's USA shop and after much back and forth I ordered a custom aluminum rad from them. I had the inlet part lengthened inside the cap to dump about mid point, and I had the radiator extended 2" on the bottom. I also had to replace the Evans because it would jell up in the winter and prevent my Espar from working. So now with the new radiator at hwy speeds 65mph the water sits at about 180F on average and south of town we have a nice 5mi long climb, and when cresting the hill the water would sit at about 193F. I also increased my boost to 12psi and played a little with the fuel. So, my take is if all else fails then maybe a modified radiator would solve your problem. Sorry for the long story.

hey coldtaco- thanks man. all the info I get helps. I had thought about a radiator. I only got mine pressure flushed as it cost almost as much to get it rodded out as a new one. may need a new cap too. im hoping the fan clutch will fix it, or I may have to get my radiator cleaned. think my pump is ok. maybe since mine isn't a turbo, it wont be so hard to keep it running cooler. I don't know anything about diesels but my old fj40 never heated up and I bet this wont either if I get it right. thanks again.

 

[coldtaco]

forgot if yours was turbo or not. Since you reminded me it's non turbo then I think you need to get your rad rodded or get a new factory spec one and get a stand alone water temp to actually know the numbers. like others have said your HZ should run just fine water temp wise if all things are working right, of course they were not designed to drive at our hwy speeds I don't think. My rad I think was still original and when the shop removed it to replace it it definitely would have been in need of getting rodded, it had some blockage. One design flaw with the 2H is that the water inlet and outlet are on the same size, yours I think is cross flowed which is a way better design. Odd Iron Offroad (I think it's called) has aluminum radiators they could sell you and their price is reasonable.

 

[mike phillips]

forgot if yours was turbo or not. Since you reminded me it's non turbo then I think you need to get your rad rodded or get a new factory spec one and get a stand alone water temp to actually know the numbers. like others have said your HZ should run just fine water temp wise if all things are working right, of course they were not designed to drive at our hwy speeds I don't think. My rad I think was still original and when the shop removed it to replace it it definitely would have been in need of getting rodded, it had some blockage. One design flaw with the 2H is that the water inlet and outlet are on the same size, yours I think is cross flowed which is a way better design. Odd Iron Offroad (I think it's called) has aluminum radiators they could sell you and their price is reasonable.

thanks again man. that's good to know cause I may need to get a new radiator. seems like aluminum is the way everyone is going these days. I need to get a temp gauge too so I will know what it is doing. once I get all things right I think I will be fine. thanks coldtaco.

 

[coldtaco]

some will say copper is better, but here in the US probably what ever you can get. your rad shop should be able to replace the core with a four core center and use your original upper and lower caps.

 

[elkaholic]

This is essentially the gauge I have but without the the dual scales

VDO 310-910: Cockpit International Water Temperature Gauge 250°F /120°C | JEGS

 

[mike phillips]

hey coldtaco- I am thinking it may be easier for me to just get my old one rodded out and cleaned up good. it didn't have any leaks and the shop guy said it didn't look bad when he pressure flushed it. but I may try and find a new 4 core as mine is a 3 core. thanks for the reply coldtaco.

 

[mike phillips]

hey sam- thanks for that. I will get one of those. I couldn't see any wires but I can call JEGS and see how it hooks up. I have always just wired the 12V ones to a hot wire that is dead when you turn the key off. may have to get a thread adaptor for the threaded end or will it screw in existing sender location? there is a sending unit that goes with it but maybe the stock one will work?

 

[renago]

Normally when problems don't have a clear explanation, I would do 1 one change at a time .
And check after that.
Adding several changes at the same time just make confusion .
Of course the one step at a time can take longer , but not necessarily .
Mike , you have an old car , but in all runs fine , you just have to clear up a few issues .
That car and motor is designed to run in any condition , not for hours or days , but months with out stopping.
I bet that once you change the fan clutch water temp , will be normal.
And you can forget all gauges , temp , radiator ecc .

Bye Renago

 

[renago]

One last point do NOT turbo your HZ1 .
Keep it as they made it .
It's not a ball of fire , never was indend to be .
But can run strong with little care for 500/600.000 km .
Quite a rarity today !

 

[mike phillips]

hey renago- yes, I think you're right. I think the fan clutch will solve my problem too. and I will just do one thing at a time. if my temp gauge ever messes up, I can get the 24V one from JEGS here in the states. I don't ever drive over 60-65 anyway and that's all I need. i'll never turbo it. just don't need to for what im doing. I may go to Colorado once in a while but most of the time ill be playing around in the Kiamichi mnts. which are only 120 miles from where I live. I sure do like this rig though. think it will be lots of fun. my fj40 was fun but with no AC I didn't drive it much. everyone who has seen this hzj73 really like it. sure do appreciate all the help.

 

[elkaholic]

One last point do NOT turbo your HZ1 .
Keep it as they made it .
It's not a ball of fire , never was indend to be .
But can run strong with little care for 500/600.000 km .
Quite a rarity today !

The one thing I would note here is that Toyota did produce a turbo version of the 1HZ, the 1HZ-T.It was not intercooled. There is at least one person here on Mud who has rebuilt their 1HZ to the slightly different -T configuration.

Based upon this, I believe it is feasible to turbo the 1HZ with minimal detriment to its reliability.

For reference only
1HZ Toyota’s Trivia
Builds - 1HZ-T HZJ78 All-Climate Expo Build

 

[mike phillips]

hey sam-thanks. I have heard of that too but as it is I am going to have to learn about a simple diesel motor and never owned one. I think for right now I will keep it as simple as I can. if I already understood these things, like most of you guys, I might do something like that but im starting at square one. thanks for your input though.

 

[roscoFJ73]

Just curious if you have the radiator shroud fitted?
There are lots of aluminium radiators now for the 7* series, I have heard good reports about them. I want to try one but the originals are long lasting if they are maintained and mine shows no signs of deterioration after 23 years.
I bought a Malaysian copy for my 1HZ engine swap into the FJ73 a few years back. It worked as good as the OEM radiator.

 

[mike phillips]

hey rosco- I think my shroud is fitted pretty good. my radiator may be a little dirty, I don't know. wonder how much you paid for the Malaysian copy? that might be an option if I have to go that way. the shop guy wanted about $250 to rod mine out and if I have to, I would just as soon get a new one I think. maybe I wont have to. it is 28 years old though. im going to try the fan clutch and see if that fixes it first but I could get a new cap for it. trying to get a cap for it when I order a fan clutch. I could clean out the rad myself with a solution of muriatic acid but I tried that once on my fj40 and caused a couple of leaks. made the mix too strong maybe. but if there was a weak spot it would probably eat it out anyway. it will sure clean it though. make it shine like a new penny. like I say, I wouldn't advise it to anyone though, as mine leaked afterwards. hopefully this fan clutch will fix it. thanks again rosco.

 

[Gun Runner 5]

One last point do NOT turbo your HZ1 .
Keep it as they made it .
It's not a ball of fire , never was indend to be .
But can run strong with little care for 500/600.000 km .
Quite a rarity today !

As with most things in life "moderation" is the key. In my opinion the 1HZ will suffer no ill effects from turbocharging if the boost (8-12 psi) and temps (efficient Intercooler) are kept under control. (again think moderation).

 

[mike phillips]

hello gun runner. will sure keep that in mind. I don't have a lot of money right now but maybe in the future I could look into it. thanks.

 

[FJBen]

hey rosco- I think my shroud is fitted pretty good. my radiator may be a little dirty, I don't know. wonder how much you paid for the Malaysian copy? that might be an option if I have to go that way. the shop guy wanted about $250 to rod mine out and if I have to, I would just as soon get a new one I think. maybe I wont have to. it is 28 years old though. im going to try the fan clutch and see if that fixes it first but I could get a new cap for it. trying to get a cap for it when I order a fan clutch. I could clean out the rad myself with a solution of muriatic acid but I tried that once on my fj40 and caused a couple of leaks. made the mix too strong maybe. but if there was a weak spot it would probably eat it out anyway. it will sure clean it though. make it shine like a new penny. like I say, I wouldn't advise it to anyone though, as mine leaked afterwards. hopefully this fan clutch will fix it. thanks again rosco.

For a new or aluminum radiator you are probably looking $350ish for the cheapest you find. The original radiators are pretty good and when fixed correctly will last a really long time. $250 seems like a good price to get redone radiator.

 

[mike phillips]

For a new or aluminum radiator you are probably looking $350ish for the cheapest you find. The original radiators are pretty good and when fixed correctly will last a really long time. $250 seems like a good price to get redone radiator.

thanks man. if that's the case then that's probably what I will do if the fan clutch doesn't work out for me.

 

[roscoFJ73]

I don't know. wonder how much you paid for the Malaysian copy?

About $400AUD from memory. Toyota charge us ridiculous amounts for landcruiser parts. So the local shops get Malay and Taiwanese factories to reproduce exact copies. I also had a top quality starter made in Malaysia and I used a Taiwanese rebuilt kit.

I think $250 is a good deal for your radiator to be checked and cleaned. You will get a few more years out of it and it will give you time to build up your knowledge of parts and where to get them at the best price.

Ive been using these on my last 2 landcuisers. They take about 10 minutes to fit and they are super reliable. I used double sided tape to fit it instead of drilling holes. There is a sweet spot under the dash where it fits nicely
ENGINE GUARDIAN WATCHDOG TEMP OVERHEATING MONITOR GAUGE WARNING ALARM SOUND | eBay