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How to install a bigger radiator in your '65-66

6K views 36 replies 5 participants last post by  guitarman584 
#1 ·
First, you cut a hole in your trunk floor.

The battery takes up too much room next to the radiator, and so must go to the trunk. This will also substantially help with weight distribution. My trunk floor was really rusty, and so needed a patch panel before I could feel confident in putting the battery box on top of it. Moving the battery to the trunk is also motivating me to clean up the wiring underhood, so hopefully that will look much cleaner at the end of all this.

As for the radiator, I am going with a 31" overall wide x 16" tall Griffin aluminum radiator. Why 31" wide? That will put the tanks right on top of the frame rails, so all I have to do is lay down a tab and some rubber on each to keep it from sliding back. I will need to cut out a bunch of the core support to make it usable, but that shouldn't be too much of an issue. This will also move the radiator forward slightly and tilt it vertically to give me more room for my electric fan, which will also be getting a home-fabricated shroud. The power steering cooler will need a different mounting method, and I'll need to rethink the upper radiator mount system, since the radiator position will be radically different.
 

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#2 ·
I ended up using the old battery tray for the base of the new battery box. Added a couple wings for the hold down rods, and a couple pads to help spread out the load. To mount it, I welded 3 bolts to the trunk floor and bolted the tray to it. Two of the bolts are welded directly above a frame rail flange, and so should be well-supported. Next up will be running the wires and rewiring the underhood power distribution.
 

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#3 ·
Battery cable location is 90% done. The rest of it goes through the A-pillar just under the door hinge into the space behind the fender and the splash guard so that the cable is always behind the factory interior panels. I'll probably put a cutout in the splash guard, then run it forward along the inner fender, through the shock tower hole, then to the starter, since I'm using a '94-95 Mustang mini starter with an always hot battery terminal. Then I'll run a smaller gauge cable from there to a power distribution block and then to the alternator.
 

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#4 ·
Most of the weekend was spent building this bracket to mount an SN95 power distribution block, which will house my fan and fuel pump relays, fuses for a bunch of different things that were previously unfused, and has a stud for mounting the alternator and battery wires. The cable from the battery to the starter is basically finalized, but I want to redo the wire from the starter to the distribution block, mostly to put an angle in the terminal at the starter end to make sure it doesn't contact anything else around it. I'll probably start wiring in the distribution block tomorrow. If my back doesn't give out, I should be able to fire it up by next weekend, so I can get the car turned around in order to pull the engine. With the engine out, I can get the rear main seal resealed, replace the steering rack, and start hacking away at the core support for the embiggened radiator. By the way, I crunched the numbers on the two radiators, and the old one had a total core surface area of 323 square inches, while the new one has 390 square inches, a 20% increase. Some will be behind the Shelby apron, but it will still be fed by the brake duct holes, so it shouldn't lose any effectiveness there.
 

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#5 ·
I've begun wiring the distribution block, which is a bit of a challenge, with some of the original block wires being reused, spliced, and reterminaled. I've done basically all I can with the block on the bench, and now everything must be wired into the car. Some wires from the car will have to be extended, others replaced. Always make a wiring diagram so that you can have a plan to work from. Mine is on a white board so that I can see it from across the garage. I'll have to figure out how to loosen the nut on the bus bar because it is super tight and I don't want to risk splicing the main power wires if I don't have to.

I think I'm still on track to fire it up this weekend.
 

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#7 ·
Thanks! I do tend to get a bit carried away with my projects, but at least this one will hopefully provide much improved reliability and serviceability, and potentially even improved handling!
 
#8 ·
Battery relocation is done, and the power distribution box is totally wired in! Wiring diagram included, viewed from the bottom side, if you wish to try this yourself. Only difference is that the choke output should be moved from the fuse to the ignition switch relay output, labeled IGN+. Also, the only reason one of those small fuses is not used is because I broke the retaining tab.

Next up, the real, intended project can begin! After I pull the engine out.
 

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#9 ·
Just did a quick trial fit to see the differences between the old and new radiator. The old one is still much bigger than the OE Mustang radiator, and this new one is bigger yet. The original idea was for the tanks to fit entirely over the frame rails, but it seems that I measured a bit short. Oh well. Now, if I was able to weld aluminum, this would give me the opportunity to weld on some brackets so I could mount the bottom of the radiator using some donut bushings. Perhaps I could braze them on instead? I'll keep thinking about the overall plan, since I also want to add A/C in the future.
 

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#10 ·
Engine is out and steering rack is replaced. The old one in black was hardly remanufactured, and ended up shedding a whole bunch of aluminum into the pump, necessitating a rebuild. Fortunately, the replacement parts for the KRC pump were only $25. Both racks are from Cardone. The original was a remanufactured rack purchased for about $80 (and a core charge that was probably about $90, since I didn't have a core), and the new one is a new manufacture unit, so hopefully that'll actually have some quality. And I'll definitely be using the warranty.

Tonight, I'll probably be working on my Ranchero, upgrading the rear lower control arms, but tomorrow I should be starting on the radiator mounting. Still haven't totally decided how to do that yet.
 

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#11 ·
Alright! We're finally on to the radiator! Got the core support cut out for full air flow, and now I need to start planning the mounting.

I still much prefer the donut bushing mounting style, with some spuds welded to the bottom of the tanks to index into the bushings, and brackets on the frame rails to hold the bushings, but I can't weld aluminum, so I'll have to take it somewhere. Other option would be some angle section or folded sheet metal to make sort of a receptacle or trough for the inside edges of the tank to rest in and locate it side to side. Upper mount system is still up in the air.

I'll also have to figure out how I'm going to fill the radiator, since the cap is going to be underneath the core support lip and basically inaccessible. Easy way would just be an inline filler cap on the upper rad hose, but the fun solution would be to add a factory-style de-gas bottle that tees into the lower hose.

And I need to mount the power steering cooler somehow (maybe directly on top of the radiator?), and plan for adding an A/C condenser. So many decisions to make!
 

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#12 ·
Fan shroud is nearly done. I figure I have on average an extra 1-1 1/2" between the radiator and water pump pulley due to removing the core support flange. Even still, I decided to offset the fan in order to guarantee clearance between the fan and the water pump pulley.
 

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#13 ·
As a side project, I mostly pulled the engine to fix an oil leak at the back of the engine. Might be a gasket, might be the rear main, I really don't know. But when I drained the oil, there was a lot of metal in it. Iron. My first thought was that the camshaft gave out and wiped a lobe, but it looks fine. What I found instead was a bunch of metal flake on one pushrod guideplate. When I pulled that pushrod out, it was clear that it was wearing into the guideplate. Two issues that I can think of that could cause this: The pushrod wasn't hardened properly, or the rocker arm is wearing out. I've been meaning to upgrade the valvetrain anyways, so I may as well go to 7/16" roller rockers and stiffer valve springs instead of the 3/8" pivot ball rockers. The current valve springs are only good to about 6400 rpm before floating.

As for the radiator part of the project, a coworker is currently welding studs onto the tanks, and once I get it back, I'll finish the shroud and make the mounting brackets for the bushings, as well as figure out the upper mount.
 

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#14 ·
Lower radiator mounts are done, and upper mount is well under way. Upper is an evolution of my old version, which was a clamp down using a sheet metal plate held down with dzus fasteners that just pulled the radiator into the core support. This time, it will be holding it fore and aft. I'll be lining the mount with foam tape to prevent rubbing. Also getting a plan together for mounting the fan shroud.
 

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#15 ·
A curiosity that I noticed (no pictures, but might add one to this post when I get home) is that 3 of the sparkplugs were very dark while the rest were kinda smudgy. The very darkest ones were on cylinders 3 and 8, both of which are connected to the right rear plenum on my Edelbrock Performer intake. The next darkest was cylinder 4, but its partner cylinder on the plenum, cylinder 7, looked fine. Perhaps I'll have to lean out the secondary jet on the passenger side. Maybe the increased plenum volume of the driver's side has an effect on the secondaries? Or it's just pulling more through the idle feed and somehow being more distributed to the rear? This will require more study, as I don't even know if this is from full-throttle pulls or just putting around town.
 
#16 ·
Shroud and radiator mounting is coming together. Got the upper mount drilled for the Dzus fasteners, and I made some tabs for the shroud that hook over the radiator top channel. I'll probably end up riveting the tabs to the shroud to keep them from vibrating and rubbing. Maybe I'll rivet them to the radiator channel as well. Gonna get some u-nuts for mounting the fan to the shroud so I can remove the fan without pulling the shroud off, especially if it's all riveted together.

In other news, I made a valve spring compressor and started replacing the valve springs and rocker studs. 7,000 rpm, here I come!
 

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#17 ·
Valvetrain is very nearly done. Just need pushrods. All else that's left on the engine is to replace the rear main seal, clean out the oil pan, put the timing chain back on, then put on all the exterior stuff. Got a new pan gasket too, which I think was the actual cause of the leak.

But I've decided that I don't like the upper mount and core support, so I'm going to cut out the top of the core support and remake it to be removable, possibly integrating the upper mount into it, as well as the power steering cooler mount. So look for some updates to that in the coming days.
 

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#18 ·
New upper core support is under construction now. Because I like them and I have four of them available, it'll be mounted with Dzus fasteners. The mount plan is to make a couple brackets to support both the radiator and the power steering cooler, which will be a significant departure from my previous sheet metal based radiator mounts, though I may make a decorative panel to cover the top of the radiator, and possibly the gap between the grille and the core support. But that's not critical for getting it running, so that will wait a bit.
 

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#19 ·
Not a huge amount of progress lately (acquiring a girlfriend will do that). But the core support top is very nearly done, and the radiator bracket design is essentially finalized. There will be tabs that go around the profile on the engine bay side of the bracket to add strength and give a place to put some foam tape to cushion the radiator, and the power steering cooler will mount to a tab on the nose side. I think it'll probably end up taking me a couple days to make it all, realistically.

But the engine is getting really close too, so I think that realistically, it'll be another week and a half or two before I finish.
 

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#20 ·
Shroud is effectively done, and the upper core support/rad mount bar is fully mounted and ready for brackets. Unfortunately my Harbor Freight angle grinder died upon starting making the brackets, so that'll have to wait until Monday.

I'm pretty happy with my shroud mounts, really. Made up 8 tabs that hook over the radiator core rails and then into the shroud to locate it, then are riveted in place. They're the same top to bottom, and hold the shroud just slightly away from the radiator so that it doesn't rub, but not far enough to let too much air to bypass the radiator with the fan going. Should figure out if I want to polish the shroud or brush it or just paint it.
 

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#21 ·
Eh, bracket doesn't have enough room for foam tape. Looks like I have to start over. Also, this is really difficult to make. Might have to just weld some of the tabs on instead of trying to carefully cut them into shape, particularly without a plasma cutter or angle grinder.
 

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#22 ·
Lots and lots of work Paul! its coming out great though :thumbsup:




J
 
#23 ·
Naturally, I've made this much harder than I really need to, but that's half the fun!

I got one bracket basically done, though I'm still not totally happy with it. But I did get some bulkhead fittings installed in the core support for the power steering cooler hoses! So that's something.
 
#24 ·
Ok, this bracket design is much cleaner and easier to make, so this is what I'm going with. Integrating the power steering cooler and radiator brackets was just too much, and this will look fine anyways.
 

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#25 ·
Core support/upper rad mount is basically done! Needs to get cleaned up, drilled for the power steering cooler, then painted. Then glue on the foam tape. Lots of little things left to do still, like put the engine back in, reassemble the interior, make the new power steering hoses, stuff like that. But the end is certainly in sight!
 

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#26 ·
Radiator is basically installed. Fan is mounted, mount fabrication is finished, and just needs paint. Then mount the power steering cooler, run the hoses, and put some foam tape on the radiator mounts, and the radiator will be as done as it can get without the engine in it.
 

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