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View Full Version : AU Radiator etc in to 3.5V8 RRC



Swarvey
1st November 2013, 02:22 PM
Okay so in a Tech Chatter thread, I sort of mentioned I'd installed the majority of cooling equipment out of my spare AU Falcon (4L inline six) into my 1987 3.5L EFI V8 RRC. I wasn't going to hijack the thermofan thread I was on, so here's a brief how-to on the installation.

First some notes:
Before I get started on the serious stuff, some background on the vehicle. I bought it 2 years ago as a wreck, bad LPG conversion done by fitter (no names mentioned aye sprint), EFI harness was rotten where they "soldered" connections. Long story short, the engine caught fire, everything that could burn and melt, did. So it probably goes without saying that the cooling system was put under a massive amount of stress, I had no reason to trust it and it eventually failed.

I should also mention that after the fire I had no intention of repairing the A/C system, so all A/C components are gone, including the condenser.

Header Tank:
The brass oem tank in my 87 sprang a leak on the seam, it was enough to depressurize the system and cause over-heating. I'd made a temporary repair (wrapped the damn thing in 3mm of fiberglass) it worked, but only temporary.
Radiator:
After I sealed up the old header tank, the radiator sprung a leak on it's passenger side seam. It was probably plugged and all sorts of other issues.

So out with the old:
--Header Tank
* Disconnect the hoses
* Undo the two bolts going through the supports and wheel arch
* Remove
-- Radiator
* Remove all hoses
* Drain coolant (responsibly)
* Undo and remove the two top mounts for the radiator
* The radiator should slide up and out with minimal effort
* While you're at it, remove the bottom hose and turn it around. Yes, turn it around, you'll find it's a near perfect fit if you swap it end-to end, it'll match up to the AU radiator with minimal fuss. See photo 3.

In with the new:
-- You'll need, nuts, bolts, washers and steel tube. I used 6mm threaded rod, ny-lock nuts, 10mm washers
* Locate where you want the tank to go - I put mine in the same location as the OEM
* Drill holes where necessary to attach the mounting bolts
* Cut your steel tube to length to raise the header tank away from the wheel arch.
-- If you look in the first two pics, you'll see the header tank raised away from the wheel arch, held in place by the hardware mentioned above. From the top down I've used:
[/ \] Ny-Lock Nut
---- Washer
=== Header tank mount
---- Washer
[==] Nut
---- Washer
| |
| | Steel Tube Spacer (cut to length)
| |
---- Washer
[==] Nut
---- Washer
=== Wheel Arch
---- Washer
[\ /] Ny-Lock Nut

Don't worry about the wires etc, it still needs tidying up. If you cut the steel tube to the right length, you'll end up with a very neat setup.

Next you'll want something for the AU radiator to sit on, I've temporarily used two old rubber dust caps from the top of the old AU's rear shock struts, sit the two plastic mounting dowels from the AU radiator in them. You won't need these until you've got the bottom hose on, it just makes it easier to connect the hose first, then put the rubber caps under it.

Temporarily connect the RRC top hose to the top of the radiator, this will hold it in place while you line up the mounting points. Since I've left the condenser (and the AU condenser) out of the equation, I've had a happy little miracle whereby the AU condenser mounts, line up with one of the steel bars the original A/C condenser fans mounted on. Line up the AU condenser mounting points with this steel bar, drill two holes, install bolts, Radiator installed. Don't forget the rubber caps on the plastic dowels at the bottom of the radiator.

Once you've installed the bolts and mounted the radiator, you can proceed to attaching hoses and clamps. The RRC top hose fits to the top of the radiator perfectly, the bottom RRC hose has to be flipped end-to-end and it lines up with pretty much no kinking or warping. Note the new route under the power steering lines.

The large hose from the header tank runs to the radiator, about half way down on the drivers side. A quick and dirty job would be to cut the hose to an approximate length as I have. But eventually I will be using new hose with 90deg brass fittings to eliminate kinking. For now, you'll see a hose clamp on there just to prevent the hose being kinked shut. Once the system's pressurized it's not a problem at all as the hose will expand.

Attach your coolant return hose to one of the small inlets at the top of the header tank, same goes for the radiator overflow/return hose

Thermofans:
* Slot the bottom of the thermofan housing into the slots at the bottom of the AU radiator, then install the two bolts at the top.

Now for the tricky bit, you'll need a way to trigger the fans at temperature, or wire up a switch etc.
For now, I've just wired them up temporarily, both fans are fed 12v straight from the battery, a relay switches their earth when ignition is in the on position. Yes this means they're on full time, but I did say this is only temporary.

That's it, that's the AU radiator, header tank and thermofans installed. Buy yourself a beer, or shout me a shot of Dram :D

Further Notes:
I am currently designing a circuit that will operate the thermofans from a 40amp PWM controller. This will operate based on the engine temperature signal which also runs to the dash. Basically I'll be splicing into the harness and using it's varied resistance to trigger a response in the PWM controller.

Shrouding is important. I had a spare piece of roof flashing laying around that was the perfect length and shape for an extended shroud. Once I'd cut a square out for the bonnet strut, it was pop-riveted into place. See picture 4.

Finally, you'll also see in the pics, a rather thick red cable attached to the battery and running along the top of the radiator. This is my 0gauge cable running to the alternator. By a happy coincidence, it fits snugly in the channel at the top of the AU radiator where a return hose used to run.

In a perfect world, I'd have bought all new OEM components to return the whole rig to a perfect, restored, mint condition truck. But the bank account and the hand brake prohibited this. So score one for ingenuity.

Swarvey
1st November 2013, 02:23 PM
Reserved for Q & A

Dougal
29th January 2014, 04:28 PM
What are the measurements of the AU radiator core and overall?

dobbo
29th January 2014, 05:32 PM
What are the measurements of the AU radiator core and overall?


sounds like your thinking what i'm thinking

Swarvey
30th January 2014, 11:28 AM
Hi guys, I've not long picked up a shiny new aluminum core rad for $90 (everyday price) I'll measure the dimensions in a short while, bit tied up relocating a rather large python, do you want an 'overall' measurement, just the core, or both?

Dougal
30th January 2014, 12:21 PM
Hi guys, I've not long picked up a shiny new aluminum core rad for $90 (everyday price) I'll measure the dimensions in a short while, bit tied up relocating a rather large python, do you want an 'overall' measurement, just the core, or both?

Oh no hurry, it can wait until after the python battle. Unless you're talking Linux.
I've got the measurements here for my 85 and 93 V8 rangie radiators. Mainly want to see how much space will go.

dobbo
30th January 2014, 03:52 PM
Would one be sufficient enough for a 4BD1

Dougal
30th January 2014, 04:04 PM
Would one be sufficient enough for a 4BD1

It doesn't take much to cool a 4BD1T in normal use.

Swarvey
2nd February 2014, 11:14 AM
Hi guys, been a busy few days working on Jeremy so I've been slack getting on here.

First of all, the Python's been relocated, apparently it was a bit ****ed off having been caught and bagged and all, but I'm sure it'll get over itself.

Secondly, I've attached a picture of the new radiator, haven't even taken it out of packaging yet, I was pleasantly surprised at how well it was packed. Keeping in mind it's a cheap aluminum clone of the original AU Falcon rad.

And here are the dimensions:
Overall
Length: 79cm (approx 31")
Height: 51cm (approx 20")
Depth: 7cm without hose barb 11cm including (approx 2 3/4" without, 4 3/8" including)

Core
Length: 68.5cm (approx 27")
Height: 56.6cm (approx 22 1/4")
Core Depth:3.2cm (approx 1 1/4")
Core Depth Inc side tanks: same as overall depth

I'm really hoping to make this modification a viable one for other LR owners out there, so if there's anything else you need to know, please ask.

Anyone know how I can edit my previous posts to include this info? I'd like to add it to post #2 if I can. Just haven't found an edit button yet.

Swarvey
2nd February 2014, 12:19 PM
To create shock-absorbing spacers for the bottom end of the radiator, cut some appropriate cooling hose to 1 5/8", slip these over the plastic dowels on the bottom of the rad. They'll sit perfectly on the chassis rails to help support the rad. Also at this height, it's not offsetting the overall height of the rad.

So with this addition, the rad is now sitting parallel to the chassis, has room to move, is sufficiently supported at both ends and the lower hose has clearance over the mount on the chassis.

Dougal
2nd February 2014, 03:50 PM
Thanks for the measurements. But I think you've got a typo in the height. The core is showing bigger than overall.
Either way, these are much taller than I was expecting.

Stock 1985 radiator core size:
690x345x50mm
Stock 1993 radiator core size:
740x400x~60mm.

I'm going to a big but thin front mount intercooler and a radiator that nests in with it. I was hoping to use falcon radiator fans, but the radiator I'm considering is approx 640x310x50 so the falcon fans aren't looking good.

Swarvey
2nd February 2014, 06:09 PM
Thanks for the measurements. But I think you've got a typo in the height. The core is showing bigger than overall.
Either way, these are much taller than I was expecting.

Stock 1985 radiator core size:
690x345x50mm
Stock 1993 radiator core size:
740x400x~60mm.

I'm going to a big but thin front mount intercooler and a radiator that nests in with it. I was hoping to use falcon radiator fans, but the radiator I'm considering is approx 640x310x50 so the falcon fans aren't looking good.

You're right, definitely must be a typo, thank god i didnt cut anything... measure twice, cut.....

Yes this rad definitely stands taller in the engine bay, just enough clearance to fit under the bonnet thought. If you're only interested in the fans, they're like 90% plastic, one could use a dremel creatively and remove some excess plastic and make them not much bigger than a davies craig. Hell you could even cut the excess out of the shroud with a good set of tin shears.

Anyhoo, I've just finished with Jeremy for the day, the new rad is in and much neater than my first attempt, this new rad could indeed be a little taller than the original (clone copy remember) as this time round, the AU condenser mounts, didn't line up with the RRC mounts like last time... strange.

So now I'm lending serious thought to designing a few adapter plates. One along the bottom to tie into the RRC rubber mounts in the chassis crossmember and line up with the AU rad mounts, a 1/8" strip of steel plus 4 bolts will make a very decent addition, along with two uprights or crossmembers to mount the rad on, or perhaps just redesign the original RRC top rad mounts, once again, some 1/8" should be more than sufficient here, weld in two dowels, bolts in original location, that should do it.

I'd say I could go and measure the original AU rad, but considering things went a little differently, and most people would be opting for the $90 throw away rad, I'll redo the dimensions when I have the fans out next.

Davo
28th April 2014, 10:16 PM
Thanks for going to the trouble of writing this up. I hadn't realised you'd done it and was wondering about it today while I measured up the radiator on my BA. (Which also looks like MAYBE it would fit.)