Author Topic: Radiator change questions  (Read 5454 times)

Offline Bradley.A.Bates@gmail.com

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Radiator change questions
« on: February 27, 2018, 06:04:54 PM »
Hello,

I have a 1984 Chevrolet C10.  The original engine (250 cu. in.) was replaced with a 327 cu. in. V-8 by the second owner.  The original radiator was left in place and a small auxiliary oil cooler was added.  Here are the dimensions of those:

The current radiator measurements:
  Height:  16 1/2"
  Width:   27"
  Depth:    1 7/8"

The current auxiliary oil cooler measurements:
  Height:   7 1/2"
  Width:  12 3/4"
  Depth:      7/8"

The engine has the original small fan from the 250 engine and no shroud around it.

The previous owner told me that no thermostat was installed and that the truck ran fine as long as it was kept moving, but might overheat in stop & go traffic.  The radiator blew after about fifteen or twenty minutes while I was towing my boat at a slow speed while I was moving it on our property.

I would greatly appreciate any suggestions on what to use to replace the radiator and auxiliary oil cooler.    truck offers a radiator that is the same size in height and width, but has two rows of tubes in the core and is 2.5" deep.  The catalog states that the radiator includes oil cooling and therefore needs no auxiliary unit.  The   catalog shows that this is the radiator to use for the same truck equipped with a 305, 307, 350, 400, & 454 cu. in. engines, so it seems like a good fit for a 327.

I would also like to know what thermostat would be best for this engine and what type of radiator cap I should use.

If you know of a better supplier that would be good to know too.

Thanks in advance for your thoughts and ideas on this,

Brad Bates

Online Rapid Roy

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Re: Radiator change questions
« Reply #1 on: February 27, 2018, 06:22:43 PM »
Welcome to the site
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline 1967KaiserM715

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Re: Radiator change questions
« Reply #2 on: February 27, 2018, 06:45:38 PM »
Engine oil cooler or transmission oil cooler?

The biggest issue will be radiator mounting.  I can't remember how much the mounts changed, but you'll likely be fine with new isolators.

I'm thinking your radiator is currently a single core, a double or triple core is better.

Get a shroud, much better ability to cool, plus get the right size fan.

I always recommend auxiliary coolers, especially when towing. Could be used in conjuction with an in-radiator cooler.

Start with a 180 thermostat. All engines are different, one engine could need a 180, the same spec'd engine could need a 190...just depends.

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Current Vehicles:1985 GMC K10(Daily) 1991 GMC K2500(Daily) 1975 Beetle(not running) 1985 Mercedes 300D(not running) 1952 M35    1967 M715(not running)
 1986 Chevy K30(under repair)

Offline Irish_Alley

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Re: Radiator change questions
« Reply #3 on: February 27, 2018, 07:45:55 PM »
a fan shroud might/should fix your overheating issue. the fan isnt pulling air over the rad without it. might be easier and better to invest in a couple electric fans and just do away with the metal fan anyway. welcome from maryland also
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Bradley.A.Bates@gmail.com

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Re: Radiator change ANSWERS to my questions
« Reply #4 on: February 27, 2018, 10:07:45 PM »
Two piece shroud is on the list along with a clutch (the current fan is fix-mounted to the water pump), but I ran across a dual electric fan system that mounts on the rear side of the radiator that looks tempting.  It is pricey, but should overcome anything I run into if I put it together right.  I appreciate that suggestion.

For Irish_Alley:  The mounts should work because the radiator is simply "thicker" or deeper than what has been used, so the little parts and pieces that hold it in place just need to be the right size (I think).

One important thing I don't get is how to use an auxiliary cooler for the transmission in conjunction with an in-radiator cooler.  It sounds reasonable, but I don't get the picture for the plumbing?  Would I run the input line from the transmission to the radiator, and then the output line from the radiator to the input for the auxiliary, and then the output from the auxiliary as the return line to the transmission?  Sort of like running two hot water heaters in series in a house?

Thanks for the welcomes -- I'm sure I will bug many members with questions as I revitalize and rebuild this truck, which I like more than I thought I would when I bought it!

Offline Irish_Alley

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Re: Radiator change questions
« Reply #5 on: February 27, 2018, 10:20:15 PM »
thats how i would plumb up an aux cooler. by time you get a clutch/fan and shroud it should be cheaper to just buy an electric fan setup. unless you find one in the junkyard or someone parting out theirs
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Offline Bradley.A.Bates@gmail.com

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Re: Radiator change questions
« Reply #6 on: March 08, 2018, 02:02:18 PM »
Dear Irish_Alley,

Thanks for the response and plumbing answer.  I will be looking for the electric fan solution too.

Best Regards,

Brad Bates

Offline 75gmck25

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Re: Radiator change questions
« Reply #7 on: March 09, 2018, 11:46:40 AM »
One of the most common 3 row radiators for these trucks is sized at 17 1/4" high and 28 1/4" wide.  Most sites list it as a CU161, or some variation of that number. 
You should not have to pay more than about $100-120 for a brass radiator of that size at a local parts store, and there are some inexpensive aluminum ones for about $180-200.

Bruce

Offline 75gmck25

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Re: Radiator change questions
« Reply #8 on: March 09, 2018, 03:36:17 PM »
If you are looking for a cheap source for a very high flow electric fan, do a web search for articles on using the Taurus, Windstar or Lincoln Mark VIII fans.  At the junkyard, pull the entire fan and shroud, and try to also get the relays and controller. Just make sure you also have enough alternator output, since some of these fans really draw some amperage.  IIRC, the Taurus fan is two speed, while the Windstar unit has two separate fans.

For alternator upgrades, consider at replacing your 10SI with a GM 12SI alternator.  The 10SI max was 63 amps, while 12SI went up to 94.  They are the exact same size, and you can buy the 12SI with a single groove pulley that will work with your V-belts.

Bruce
« Last Edit: March 09, 2018, 03:39:08 PM by 75gmck25 »

Offline Bradley.A.Bates@gmail.com

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Re: Radiator change questions
« Reply #9 on: March 09, 2018, 05:38:15 PM »
Many thanks for all of that information Bruce.  I am beginning to really like this group.

Best Regards,

Brad Bates

Offline Bradley.A.Bates@gmail.com

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Re: Radiator change questions
« Reply #10 on: March 16, 2018, 11:28:16 PM »
If you are looking for a cheap source for a very high flow electric fan, do a web search for articles on using the Taurus, Windstar or Lincoln Mark VIII fans.  At the junkyard, pull the entire fan and shroud, and try to also get the relays and controller. Just make sure you also have enough alternator output, since some of these fans really draw some amperage.  IIRC, the Taurus fan is two speed, while the Windstar unit has two separate fans.

For alternator upgrades, consider at replacing your 10SI with a GM 12SI alternator.  The 10SI max was 63 amps, while 12SI went up to 94.  They are the exact same size, and you can buy the 12SI with a single groove pulley that will work with your V-belts.

Bruce

Thank you Bruce and everyone else who helped out on this.  I am looking at upgrading the alternator to something like a CS130 Delcotron alternator and thus skipping past the 12SI because I want the option to add additional electrical components later in life.  I'm glad you mentioned the alternator because I would not have thought of it until it started smoking!

I found a 4-row aluminum drop-in replacement radiator, dual 14" electric fans, a sensor & wiring kit, and a stainless 1 quart overflow tank via shopping (a lot longer than I like) on Amazon.  The radiator was $224.00, tank $25.69, fans and sensor with wiring kit $89.95.  Prices were more reasonable than those I found on the reseller sites I tried, and the Amazon site just uses resellers for this stuff anyway, so there should be no difference.  I get free shipping as a Prime member, and when I tested the reseller by sending a question via email about which radiator they recommend I got a response within an hour or so and the correct answer.  I am foregoing the use of a shroud for now to allow the constant airflow through the entire core rather on relying airflow drawn by the areas covered by the fans alone.  All that plus the auxiliary transmission oil cooler mounted up front with some thick rubber spacers between it and the radiator core should resolve the heat issues.

Budget manager here is forcing me to wait until next month to buy a new alternator and the pressure washer I have needed for weeks now.  At least I have someone keeping an eye on me!

I have an extang tonneau cover that will be my next project.  After that it will be shocks, a new gas tank assembly or at least a repair (it leaks when I top it off), tire rotation and front-end alignment (if needed), tightening the steering just a bit, and a new dash and bench seat.

Eventually I will disassemble and repaint the entire truck, frame and all, but that's a bit further down the road.

Thanks again everyone!

Brad Bates

Offline psyguy23

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Re: Radiator change questions
« Reply #11 on: May 16, 2018, 12:21:02 PM »
Hi Bradley.

The radiator setup you bought from Amazon sounds like the exact setup I just bought. I am curious how you mounted yours securely. Mine seems to fit about 1” too low and about 1/2” too shallow from the outer edge of the factory mounting bracket to hold it securely up top.

Once I get mine Mointed I can start searching forum on best way to electrically hook up dual fans.

Thanks in advance.

1983 GMC K1500. Factory 5.7L.
1983 GMC K1500 4x4 5.7L
Daily Driver, Long Term Project
SMOG is no problem.

Offline Bradley.A.Bates@gmail.com

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Re: Radiator change questions
« Reply #12 on: May 31, 2018, 03:22:57 PM »
Hey!

Sorry I haven't responded sooner.  I just finished this project yesterday.

The radiator I bought has two holes drilled through the top frame piece.  When I set it in place those holes lined up with the cross member that is in front of the radiator.  So I drilled two holes in that cross member to match the radiator and used two box pan self-tapping screws with a flat washer and a lock washer for each to secure the radiator in place.

I hope that helps.

Brad Bates

Offline psyguy23

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Re: Radiator change questions
« Reply #13 on: June 06, 2018, 01:06:37 PM »
Thank you Bates that is helpful. After ordering different sets of radiator mount bushing I finally found a winning combination.

I’ll mount up with a piece of flat bar to tie together the radiator mounts from the chassis to the top of two mounting points from the radiator. This will tie all the top together and make it ridged.

The radiator is fairly stiff between the rubber mounts, hoses and lines from trans. This will just make it that much more secure.

Some have said I shouldn’t because factory setups are not ridged and should have play.
1983 GMC K1500 4x4 5.7L
Daily Driver, Long Term Project
SMOG is no problem.

Offline roadrunnerkitten

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Re: Radiator change questions
« Reply #14 on: June 14, 2018, 02:27:01 PM »
Hey!

Sorry I haven't responded sooner.  I just finished this project yesterday.

The radiator I bought has two holes drilled through the top frame piece.  When I set it in place those holes lined up with the cross member that is in front of the radiator.  So I drilled two holes in that cross member to match the radiator and used two box pan self-tapping screws with a flat washer and a lock washer for each to secure the radiator in place.

I hope that helps.

Brad Bates
U got pics brad? I’d like to see my next project


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