Builds 1974 HZJ40 Build (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Did you put a sensor in there? That would be a neat thing to monitor although I don’t think you have a ton to worry about with 33” tires and no hydroboost or hydro assist. cooler steering fluid is always better though.
No sensor; I'll check it with an IR thermometer.

Wiring is done, and it is running and driving, but there is a significant oil leak from the back of the head gasket. I take it in Tuesday to have the windshield put in, then I'll start pulling the head.

IMG_20190705_105457.jpg

IMG_20190705_105419.jpg

IMG_20190705_151257.jpg

20190706140125.jpg

IMG_20190706_140729.jpg
 
Pretty cool build.

You could 3D print a mold and use some air hardening urethane to make a flexible gasket. I guess you could use a flexible 3D printing filament too if your printer supports it.
 
Pretty cool build.

You could 3D print a mold and use some air hardening urethane to make a flexible gasket. I guess you could use a flexible 3D printing filament too if your printer supports it.
Thanks. I've been using flexible filament for a bunch of body plugs and grommets, like this one for the 4x4 vacuum lines.
IMG_20190710_102855.jpg

nice work Charlie. Ps cooler shouldn't be an issue where it's at, I've mounted several in that location before. How bout that moment when you realize the taillights have to come back off to bolt the tub back down. :)
Yeah, I'll check the fluid temp, but I really doubt it will be a problem.
It wasn't as bad as the moment I realized that this had to happen... :bang: It was leaking so bad that after 50 miles of driving, the rear axle was covered in engine oil.
IMG_20190709_212923.jpg


Gaskets and head bolts arrived yesterday, precups and valve stem seals should be here this evening. There are no visible cracks on the head and it doesn't appear to be warped. I'll take it in to the machine shop tomorrow to have it magnafluxed and cleaned. Hopefully they can get it in quick and building the exhaust doesn't take too long because I need to put some miles on it before the solid axle summit.
 
Sheesh.
Where was the leak coming from?
Back of the head gasket. Looks like it was from the pressurized oil feed hole to the head. The mating surface around that hole was coated in oil.
IMG_20190710_142238.jpg

IMG_20190710_150432.jpg
 
Back of the head gasket. Looks like it was from the pressurized oil feed hole to the head. The mating surface around that hole was coated in oil.
View attachment 2026032
View attachment 2026035
Hmmm... that's equal parts interesting and disturbing. How were the head bolts in that area when you pulled the head? I can't imagine that it would take a terrible amount of clamping pressure to seal the oil orifice hole (especially compared to the clamping pressure required to seal the combustion chambers.

I would have suspected the rear cam seal would be the most likely source of a leak? Was it wet around the back end of the valve cover.

Let us know what the machinist says about the head.
 
Hmmm... that's equal parts interesting and disturbing. How were the head bolts in that area when you pulled the head? I can't imagine that it would take a terrible amount of clamping pressure to seal the oil orifice hole (especially compared to the clamping pressure required to seal the combustion chambers.

I would have suspected the rear cam seal would be the most likely source of a leak? Was it wet around the back end of the valve cover.

Let us know what the machinist says about the head.
Valve cover or rear half moon plug was what I thought at first too, but it was definitely coming from down lower. The head bolts were all tight, but some were tighter than others - makes me wonder if someone re-torqued them or had the head off at some point. It still had the original gasket, so that would mean that it was reused, but, considering some of the other work that was done to the powertrain, reuse of a head gasket wouldn't surprise me.

BTW, once I have it back together I'll probably post a video showing the gauge cluster, wiring, and everything else that I haven't been posting over the last month.
 
Very nice swap dude. You'll work through the issues.
 
Very nice swap dude. You'll work through the issues.
I hope so. I'm moving out next month and don't want to be driving back every weekend to finish it.

The head should be done Monday and the last parts order is due Tuesday, so I am hoping to get it in for the exhaust by the end of next week. That would give me a couple of weeks to break in the diffs and gain some confidence in it before the 3000 mile trip.

The soft top arrived today, but the bow kit still hasn't shipped. Might have to rush the powder coater to get done in time.
 
The head came back yesterday. The machine shop installed new valve stem seals and verified that it was not cracked and that the warpage was within spec. The old precups had not yet fallen apart, but a few of them were developing cracks. Now it has a set from Engine Australia.

After driving ~100 miles today, there was no oiI leakage, so I'm calling that job a success. I installed the wipers, so it should pass inspection now. It goes in Friday morning to be inspected and get an exhaust.
IMG_20190717_203836.jpg

IMG_20190716_154913.jpg
 
I've put a little over 300 miles on it now, and it drives surprisingly well. The only problem is that it is running too hot at high speeds. Around town, it sits at 183°-185° but once it gets past 60 mph the temp starts climbing. At 70mph it runs in the 220s. I am really not sure what the cause could be, since the entire cooling system is new. Here is what I have checked:

Thermostat verified working in pot of water
Heater blows hot, temps run ~10° cooler with it on
No loss of coolant
No bubbles in the overflow
When hot, there is a 15° difference between the upper and lower rad hoses

The fitment of the CSF radiator is pretty poor, so I have an OEM rad on the way. Hopefully that makes a difference in the temperature, but I doubt that it will. Does anyone have anything else to check?

IMG_20190718_201721.jpg

IMG_20190718_203608.jpg
 
I'm having good performance and temps with an aluminum Champion 3 row radiator on my turbo'd 1HZ powered 60.

Is the CSF brass? What are the ambient temps like? Is the fan clutch working well? Are you running a fan shroud?
 
Is the CSF brass? What are the ambient temps like? Is the fan clutch working well? Are you running a fan shroud?

Yes, it's brass. Ambient temps in the low 90s. Also worth noting that this is only at 1200' of elevation and not pulling any significant hills. Fan clutch is new OEM, but I can't hear it working with the exhaust dumping in the engine bay. It goes in tomorrow for the exhaust, so I will listen for it once that is done. Yes, I am using the fan shroud and radiator frame designed for this swap from crushers. They are made for an OEM radiator, so hopefully the one I ordered will fit better than the CSF.

Thanks for the help.
 
I wonder if it's the exhaust that's increasing engine temps? It will be interesting to see how your temps are after the exhaust goes in.
 
I wonder if it's the exhaust that's increasing engine temps? It will be interesting to see how your temps are after the exhaust goes in.
We should know later today. On the way to the exhaust shop, I got it up to 215° and pulled over to check a few things. I was surprised by how little air was being pulled through the radiator; even at 2000 rpm, I doubt that it would be enough to stick a sheet of printer paper to the rad. Now I'm thinking that the new fan clutch isn't strong enough - I'll give it the finger in the fan check once the exhaust is done.
 
What temperature is the 1HZ supposed to run at? Like, from the FSM?
 
Last edited:
We should know later today. On the way to the exhaust shop, I got it up to 215° and pulled over to check a few things. I was surprised by how little air was being pulled through the radiator; even at 2000 rpm, I doubt that it would be enough to stick a sheet of printer paper to the rad. Now I'm thinking that the new fan clutch isn't strong enough - I'll give it the finger in the fan check once the exhaust is done.

Hmm. That's not good. I get good suction on mine and it's going through the radiator, condenser, and intercooler. Might be good to swap another fan clutch in and re-test.
 

Users who are viewing this thread

Back
Top Bottom