26.1 Down Flow Radiator Install w/ Electric Fan

How to tell if you have a V8 or 6-cylinder Core Support

How to tell if you have a V8 or 6-cylinder Core Support

Note:  1955-57 Chevy’s mounted their radiators in different positions, depending on which engine was installed, V8 or 6-cylinder.  The V8 radiator mounted in the V8 position, engine side of the core support, and used a V8 core support.  6-cylinder cars mounted the radiator on the grille side of the core support for clearance, since the 6-cylinder was longer than the V8, and used a 6-cylinder core support.  The handy info page to the left will explain things better.  Click the pic for a larger version.

Keep Your Cool!  With our radiator install article…(26.1-15.2)

Car show season will be here before you know it and that could mean lots of driving and perhaps driving in the heat, as we get closer to summer. In this install article we show you how to keep your classic cool, and dress her up a little, with a new aluminum radiator and an electric fan.

If you are running a stock engine in your classic then the stock cooling system is probably all you need. But if you are running a high horsepower engine, in stop and go traffic (like a cruise), chances are you have experienced some problems with cooling. Changing over to a system designed and built with today’s technology will go a along way to keeping your car from limping along the side of the road looking for the nearest watering hole. Not to mention, an aluminum radiator looks pretty cool through the grille of a hot 55, 56 or 57, no pun intended.

 We are installing an electric fan and our car uses a V8 core support. There is not enough room between the back of the radiator and the front of the engine to put the fan in the V8 position, so we are utilizing Danchuk part # 11236 conversion brackets to move the radiator to the 6-cylinder position. This will give us the necessary clearance. If your car already mounts the radiator in the 6-cylinder position, and you are running a V8, you will not need these brackets, as you will have plenty of room already.

You will need these Danchuk parts:

13270  Radiator, you can also use the 13274 triple flow (Or the down flow radiator of your choice although some modification of these instructions may be necessary)
13452  Electric fan kit
11236  Conversion brackets, 6-cylinder position
11236A  Fan mounting brackets
044  Upper radiator hose
10856  Lower radiator hose
12163  Hose Clamps (4)

You will also need:

Semi-gloss black spray paint
Scrap cardboard (enough to cover the fins on the radiator for protection)
Masking tape
Hose cutter, razor cutter or carpet knife
Flat blade screwdriver
3/8” ratchet
7/16 and 1/2” 3/8 drive sockets
7/16”, 1/2” and 9/16” open-end wrenches
Drip pan for coolant

1.)  Drain the coolant from the radiator into the pan by opening the petcock that is located on the front of the bottom tank, grille side.

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15.1 Down Flow – 001







2.)  Once it is drained, use your flat blade screwdriver to loosen the clamps holding the hoses to the radiator, thermostat housing and water pump and remove them.

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15.1 Down Flow – 002







3.)  If your car is running an automatic transmission, disconnect the oil cooler lines from the bottom of the radiator, engine side, using your 1/2” and 9/16” open-end wrenches. Work carefully here, as you don’t want to twist the cooler lines. Loosen the bolts on the side of the radiator using your 9/16” socket or open-end wrench and 1/2” open-end wrench and remove them. (Watch for any shims that may be between the core support and the radiator and save them. If you are running a 6-cylinder core support you may need them again.) Remove the radiator and set it aside.

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4.)  With the radiator out of the car, remove the stock fan from the water pump using your 1/2” socket and 3/8” drive ratchet.

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15.1 Down Flow – 005







5.)  Once it is removed, put the bolts back in place and tighten them to secure the pulley back to the water pump.

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15.1 Down Flow – 006







6.)  Remove the conversion plates from their package. (If you have a 6-cylinder core support you will not be using them.) Hang them in a convenient place and paint them black to match the core support.

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15.1 Down Flow – 007










7.)  While you wait for them to dry, remove the new radiator from the box. Be careful, as the fins on an aluminum radiator are fragile. Using your razor cutter cut two pieces of cardboard large enough to cover the radiator core. Tape them in place on both sides of the core with masking tape. This will help to protect the fins while you to the installation.

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15.1 Down Flow – 008







8.)  Install the conversion plates by lining the horizontal holes up with the original holes in the core support where the radiator mounts. The other end of the plate passes through the core support opening to the front side near the grille. Then install the provided bolts into place, (leave loose at first, you will tighten using your 1/2” and 9/16” open-end wrenches)

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15.1 Down Flow – 009










9.)  Test fit your radiator. Adjust the brackets so the radiator fits without interference and tighten.

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15.1 Down Flow- 010







10.)  Remove the radiator and place face down on a bench. Remove the cardboard from the inboard side.

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15.1 Down Flow – 011







11.)  Next, install the electric fan, which mounts directly on the back of the radiator.

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15.1 Down Flow- 012







12.)  You will either have to fabricate brackets yourself (or use what Flex-A-Light provides), or you can purchase the brackets we made for the application that sandwich between the conversion brackets and the mounting brackets on the radiator. (Danchuk # 11236A)  A rubber seal around the front of the fan seals against the radiator core so the fan pulls air through the core, not from around it.

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15.1 Down Flow- 013







13.)  Attach the bracket to the fan with the provided bolts and tighten with your 1/2” open-end wrench.

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15.1 Down Flow – 014







14.)  Being as careful as possible (a second set of hands will help here) mount the radiator/fan assembly in place between the conversion brackets.

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15.1 Down Flow – 015







15.)  Install the bolts and tighten using your 1/2” and 9/16” open-end wrenches. Make sure the fan is snug against the core but not too snug. You don’t want to damage the fins.

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15.1 Down Flow – 016










16.)  Using your flat blade screwdriver and two new hose clamps, install the lower radiator hose.

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15.1 Down Flow – 017










17.)  Then install the upper hose on the thermostat housing. It will be longer than it needs to be so line it up and trim it the proper length with your hose cutter and install with a new hose clamp.

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18.)  Install the radiator overflow hose by pushing over the hose bung.

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15.1 Down Flow – 020







19.)  You can now fill the radiator with coolant, check for leaks and install a new pressure cap.

Note:  The stock rating for the radiator pressure cap on 55-57’s was 7 lbs. If you are using an original heater control valve and heater core do not install a higher-pressure cap, as you will damage the valve. If you are running an aftermarket AC system with an updated heater core you may be able to install a 12-16 lb. cap. Check the manufactures recommendations.

All you have left to do is wire up the fan.  As there are numerous places the electronics can be mounted and different configurations for AC and non-AC cars, we are leaving that up to you.  Follow the manufacturers instructions, which are included in the fan kit.

Our new aluminum radiator looks great, and it works really well too!   Best part is you can do this job in an afternoon.  Help your classic beat the summer heat with a new aluminum radiator and electric fan.  All the cool cars are doing it.

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You can download a .zip file with this article and all the photos by clicking HERE.
You can download just the article in .pdf form by clicking HERE.


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