Changing radiator support from 22 to 26

[cal30_sniper]

Yes, if you block the outer 2" on both sides you haven't improved it

By that logic, adding an extra row or two to the radiator would do nothing to increase cooling capacity. It’s a lot more than frontal area.

 

[MIKESPOLARA]

By that logic, adding an extra row or two to the radiator would do nothing to increase cooling capacity. It’s a lot more than frontal area.

It won't if air flow isn't passing on those extra tubes/fins. Adding a radiator wider then the hole might gain some residual flow passing around it but it's not the way it's done for max cooling

 

[Nxcoupe]

Like putting cardboard in front of a radiator. It's science.

 

[cal30_sniper]

It won't if air flow isn't passing on those extra tubes/fins. Adding a radiator wider then the hole might gain some residual flow passing around it but it's not the way it's done for max cooling

The face of the radiator does not sit right against the support, there’s a gap. At stop and low speeds, when most cars have the most trouble cooling, the fan and shroud will have no issue pulling air through the extra 26” core surface area, regardless of whether or not it’s shielded from the free stream velocity. Pressure differential will do a similar thing at speeds, but the faster you go, the more pronounced the shrouded fin effect will be. This is how cars with grills smaller than the radiator work (along with ducting from underneath on some).

Like putting cardboard in front of a radiator. It's science.

That won’t do much unless the cardboard is right against the front face of the radiator.

 

[moparedtn]

I have a couple threads on here of my trevails with Fred the '68 GTX, who was born with a 22" radiator
but now sports a 26" Griffin.
One details how I went about exactly centering the Griffin on the CL of the water pump/fan and thereby
being able to utilize a factory 26" shroud + a 7 blade steel fan (from Summit).
Couldn't use a clutch fan of any sort - the Griffin is that damn thick.

As far as the support opening goes, I had it mounted in the stock 22" opening for a while and that's ok -
but it's not optimum, since this is all about airflow after all.
The opening on 22" supports is the same on the drivers' side as a 26", at least on mine...
So, I decided it was time to open up the thing to 26" not by replacing the right side of the support, but
rather by cutting the 22" support as seen in this thread:
Redneck radiator support 101 - 22" support modded for 26" radiator

I know I'm not alone with doing that - some other members here spoke up also and said they did the same thing.
Worked fine for me - after that, I just drilled new passenger side mounting holes and used whatever washers/hardware needed
to mount the radiator properly as before (again, the drivers' side hole work pretty well as is).

 

[Nxcoupe]

The face of the radiator does not sit right against the support, there’s a gap. At stop and low speeds, when most cars have the most trouble cooling, the fan and shroud will have no issue pulling air through the extra 26” core surface area, regardless of whether or not it’s shielded from the free stream velocity. Pressure differential will do a similar thing at speeds, but the faster you go, the more pronounced the shrouded fin effect will be. This is how cars with grills smaller than the radiator work (along with ducting from underneath on some).


That won’t do much unless the cardboard is right against the front face of the radiator.

Let's just say our experiences differ. Having the radiator opening shrouded by steel with a 1/4" gap for air to flow isn't the same as having that same area open to and exposed to the flow. It can't be.

 

[Dave6T4]

I did this exact thing when I was building my One-of-None 1967 Coronet R/T station wagon. The driver's side radiator mount is the same, whether 22" or 26" so, only the passenger side of the rad support needs to be modified. I broke all the spot welds loose, and found a fairly flat area of the support with no holes or embossments. I cut down through this area with a body saw and removed it from the support. I then bolted this piece to the passenger side of the 26" radiator, using the factory mount holes. Then, I bolted the radiator to the driver's side of the rad support , so the newly attached piece overlaid the remainder of the passenger side rad support. I scribed a line down the piece attached to the radiator. After this, I broke some more spot welds, and cut down the scribe mark with a body saw (plasma cutter would work well here, too), and removed this piece of rad support. Since my car was going to body and paint, I had my body guy weld it up and body work it before paint. When it was done, it looked factory.

 

[cal30_sniper]

Let's just say our experiences differ. Having the radiator opening shrouded by steel with a 1/4" gap for air to flow isn't the same as having that same area open to and exposed to the flow. It can't be.

At low speeds where cars typically have trouble cooling, it doesn’t matter. If you’re building for a road course or circle track application with sustained high speed high power operation, the picture might be different, but I kind of doubt it based on the frontal opening area of a Daytona or Superbird (keeping with the b-body theme)

At 60mph, a 22” core opening lets through about 15000cfm, which is way more cooling than you’ll likely ever need. At that point, it becomes a question of how much heat that 15000cfm can exchange, which a 26” core radiator has a distinct advantage in relative to a smaller 22”.

The free area of a radiator is only about 75% (the rest is fin and tubes). A 22” core opening is 85% the surface area of a 26”. There’s still more open surface area in a 22” core opening than a 26” core radiator has for air to pass through. Duct the radiator, and it won’t matter. In a non-ducted radiator, which probably describes 98% of the cars on this board, all that extra air is going around the radiator anyways.

 

[Cranky]

I’m asking for friend who has a 2dr 66 post car that had a /6

He got a 67 4dr from me with a
318 A/C car with a good radiator and shroud.
He is transferring everything from 4dr into 2dr.
He is having trouble finding a 22 inch 3 or 4 core radiator.
I’m suggesting that we take the radiator support from 4dr and use in 2dr.
Never having done this before I’m just wondering how difficult it is to do?
IMO It looks unfinished to just put in 26 where a 22 was.

View attachment 1504169

It may look unfinished but you would be saving yourself labor if it works and there's only one way to find out if it will. Imo, it will and a 4 core radiator is going to have really small tubes and the 4th row won't be doing much if anything other than adding volume as by the time the air gets to it, it'll be hot. You'll be better off with a 2 row that's just as wide as a 4 row radiator. Large tubes are always better then small ones and will actually have more volume.

 

[Cranky]

Pic of a 4 row rad vs a 2 row large tube rad....

 

[MIKESPOLARA]

Pic of a 4 row rad vs a 2 row large tube rad....

View attachment 1504503

The advantage is the increased fin area of a large tube aluminum radiator. Air passing over the fins is what cools the water, not volume of water. A one row alum with 1.5" tube works very well also as air flow is not restricted by other rows. I had a Chevy SSR with 490 hp LS engine it comes with the 1 row alum radiator and I was shocked at how well it cooled.
I'm in the process of changing the radiator on my Fury right now. I did buy a 2 row 1.25" tubes alum. I was really surprised at the factory radiator I took out. It has 2 rows, copper brass and cools fairly well but seemed border line at frwy speeds on a hot day

 

[Cranky]

The advantage is the increased fin area of a large tube aluminum radiator. Air passing over the fins is what cools the water, not volume of water. A one row alum with 1.5" tube works very well also as air flow is not restricted by other rows. I had a Chevy SSR with 490 hp LS engine it comes with the 1 row alum radiator and I was shocked at how well it cooled.
I'm in the process of changing the radiator on my Fury right now. I did buy a 2 row 1.25" tubes alum. I was really surprised at the factory radiator I took out. It has 2 rows, copper brass and cools fairly well but seemed border line at frwy speeds on a hot day

Don't know if you see my earlier post post here about having a single row radiator in my Dakota.... that truck always ran warm with the factory 2 row brass copper rad and especially so on 100° days with the AC running and stopped at a traffic light. Now I can't make it get hot.

 

[mrmolding]

Wanted to drop in my current experience. I had Glen Ray change my 22 to max cool for my 70 RR. I thought about upgrading to a 26, but the car was recently repainted so I hoped that the 22 would work. The car does not have A/C, but with a NOS Robertshaw 180 and the re-core from Glen Ray, this is the coolest running mopar I've ever owned -- in 100 degree desert heat. Maybe get the 22 re-cored?

 

[tanglewoodHemis]

I did this back 66. Dave6T4 said it correctly. Driver’s side mounting is the same for both radiators. A piece of metal must be cut from the passenger side. Drill 2 holes that will accommodate original fasteners, line up with radiator holes. I don’t recall any welding.
Dress the cut, prep for painting, paint. Did this on 66 Charger that was 6 mos old, so I could install the Hemi radiator.
All 66 & 67 B bodies should be the same.

 

[Dave6T4]

I did this back 66. Dave6T4 said it correctly. Driver’s side mounting is the same for both radiators. A piece of metal must be cut from the passenger side. Drill 2 holes that will accommodate original fasteners, line up with radiator holes. I don’t recall any welding.
Dress the cut, prep for painting, paint. Did this on 66 Charger that was 6 mos old, so I could install the Hemi radiator.
All 66 & 67 B bodies should be the same.

I wanted to keep the original flange all the way around the rad opening. Your way works, but the flange on the passenger side is gone.

 

[tanglewoodHemis]

I wanted to keep the original flange all the way around the rad opening. Your way works, but the flange on the passenger side is gone.

Ok

 

[tanglewoodHemis]

Dave, you are correct.
You seem to be pretty knowledgeable, so I have question for you.
Back in 66 I don’t remember ever having cooling problem with the stock radiators, even in west Texas in the Summer.
Now talking to guys a car shows, and mine, we are having cooling problems with original radiators that have been reconditioned and look like new.
My restored 66 Hemi overheats in slow traffic. No problem on highway. Has 7-blade fan with original shroud. ????

 

[Dave6T4]

Dave, you are correct.
You seem to be pretty knowledgeable, so I have question for you.
Back in 66 I don’t remember ever having cooling problem with the stock radiators, even in west Texas in the Summer.
Now talking to guys a car shows, and mine, we are having cooling problems with original radiators that have been reconditioned and look like new.
My restored 66 Hemi overheats in slow traffic. No problem on highway. Has 7-blade fan with original shroud. ????

When I first built my wagon, I replaced the original 318 with a 383. The car came with a 22" rad, and struggled with keeping the 383 cool. When I later went with a 440, I knew I was going to need a bigger radiator. I never had overheating problems with that combination. My current 1967 R/T with a 440 came with a 26" rad, and it never runs hot. We get quite a few 80 and 90 degree days up here in Ontario, and it has always been good, highway or town driving.
Did you know there are 2 different water pumps for Big Blocks? one is for A/C, and another for non-A/C. The difference between them is the pitch and number of vanes the pump has. Because of the size differences of the pulleys used with each system, the water pumps ran at different speeds. The non-A/C pump ran faster than the A/C pump, and had 5 vanes to move the coolant through the radiator. Because the A/C pump ran slower than the non-A/C pump, it was designed with 8 vanes to keep the coolant flowing at the proper rate. Some guys thought they should run the A/C pumps on their non-A/C cars to cure any potential cooling problems, because they would get more coolant flow. The problem here is that the coolant gets pumped through the rad so fast, that it does not get the same opportunity to lose heat to the air coming through the radiator. The car will actually run hotter with the wrong pump. The same applies with running the wrong pump on a A/C car. The slower running pump with fewer vanes will not pump enough coolant through the rad to keep it cool. Externally, both pumps look the same.

 

[Don67Satellite]

It really doesn't look as drastic as some people say it is when running a 26" radiator in a 22" core.

I was at a local cruise night last weekend speaking to a guy with a really nice 4-speed '68 GTX, and happened to notice that was the setup he has. Copper Mopar rad, mounted in the factory left side mounting holes, with a factory shroud and 7 blade fixed fan/spacer. Said he runs a 160 thermostat and has never had temp issues in slow traffic on hot days.

That big fan with shroud will be pulling air through there no problem. It's not "correct", but who cares.

 

[tanglewoodHemis]

When I first built my wagon, I replaced the original 318 with a 383. The car came with a 22" rad, and struggled with keeping the 383 cool. When I later went with a 440, I knew I was going to need a bigger radiator. I never had overheating problems with that combination. My current 1967 R/T with a 440 came with a 26" rad, and it never runs hot. We get quite a few 80 and 90 degree days up here in Ontario, and it has always been good, highway or town driving.
Did you know there are 2 different water pumps for Big Blocks? one is for A/C, and another for non-A/C. The difference between them is the pitch and number of vanes the pump has. Because of the size differences of the pulleys used with each system, the water pumps ran at different speeds. The non-A/C pump ran faster than the A/C pump, and had 5 vanes to move the coolant through the radiator. Because the A/C pump ran slower than the non-A/C pump, it was designed with 8 vanes to keep the coolant flowing at the proper rate. Some guys thought they should run the A/C pumps on their non-A/C cars to cure any potential cooling problems, because they would get more coolant flow. The problem here is that the coolant gets pumped through the rad so fast, that it does not get the same opportunity to lose heat to the air coming through the radiator. The car will actually run hotter with the wrong pump. The same applies with running the wrong pump on a A/C car. The slower running pump with fewer vanes will not pump enough coolant through the rad to keep it cool. Externally, both pumps look the same.

Thanks Dave for the good info.