Time for a Radiator Upgrade...?

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Itali83

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That radiator core is F@cked. See how just the few rows we can see are almost completely plugged with deposits? Every row looks the same. You aren’t getting **** for flow through the radiator and therefore very little heat transfer.

also, unless you drained water out to see the inside of the radiator. You are very low on “coolant” (Rusty water that is). Another factor to your overheating.
Ben.
 

7900_Blazer

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That radiator core is F@cked. See how just the few rows we can see are almost completely plugged with deposits? Every row looks the same. You aren’t getting **** for flow through the radiator and therefore very little heat transfer.

also, unless you drained water out to see the inside of the radiator. You are very low on “coolant” (Rusty water that is). Another factor to your overheating.
Ben.

@Itali83 back to my original question… suggestions on an upgrade - maybe I should have said ‘replacement’?

3 core?, 4 core?, aluminum, new stock, get this one rotted out, electric fans, stock fan???
 
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AuroraGirl

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are you gonna be driving this truck or is it parked for now? If parked, drain the radiator and show me the fluid. It may influence recommended replacement
 

7900_Blazer

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are you gonna be driving this truck or is it parked for now? If parked, drain the radiator and show me the fluid. It may influence recommended replacement

I drive it daily… coolant has been replaced twice before I drove it to Colorado and back in late July; once when I replaced the water pump, then again when I replaced the harmonic balancer a few weeks later.
 

7900_Blazer

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Uh.. what’s up with your fan? No clutch and an extension? It’s too far in the shroud

That’s the way it was when I picked it up in Denver and trailered it home.

Was considering going electric as part of a potential update to the radiator… Googled and saw a few aluminum replacement radiator with dual electric fans… but wanted input from you all.
 

AuroraGirl

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You need an update on the charge side of things first

that 10si won’t like that much

if you have any other electrical demands, without throwing a dual belt pulley on snd making that work, you may get away with a belt if the wrap is as good portion on a cs130, but it also means installing a good fan controller.
If you want to do your charging system which includes charge wire and some grounds, you could do that. But if you don’t want to tackle that beast you need to buy a clutch and I think that might set your fan in the right spot provided you have the same thickness rad
 

AuroraGirl

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I found another ring a ding ding issue

your fan. I bet you it gets really flat when it’s running especially down road.
You must be registered for see images attach

No clutch, direct drive. Waste of energy and also probably why the fan goes flat. Those non metal blades rip can’t handle the sbc

You must be registered for see images attach

I domt like the look of the vpnelt down there. Also your alternator pulley… that’s not suppose to be that deep. Can I see top down shot of belts as center as possible amd ome from the front

also,need a clutch amd fan blades
 

7900_Blazer

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Any thoughts from anyone on my original question?

2 core, 3 core 4 core radiator?
Aluminum or 'stock' type?
Electric fans or stock fan?
Best place to order or have my original rotted out?

Thanks again for any help.
 

AuroraGirl

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Any thoughts from anyone on my original question?

2 core, 3 core 4 core radiator?
Aluminum or 'stock' type?
Electric fans or stock fan?
Best place to order or have my original rotted out?

Thanks again for any help.

Fix your radiator with a shop, get a new fan blade and clutch and see where it places your blades in relation to the shroud.

Being you just ignored my post on charging system I DEFINITELY don't recommend a electric fan. You also ignored the very real belt dilemma you seem to have which is going to **** your day in either a belt or electric drive fan, so that's nice.

You want help but it seems like you have determined the answer you will accept but are trying to squeeze it out of us.


I can do this all day. Lol.
 

82sbshortbed

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I would start with a good flush and see if that gets the radiator to allow the coolant to flow better. I used prestone flush but. Any will work fine. Maybe you'll have to do it twice as yours looks pretty clogged. It's cheap and easy and then go from there.

I'm not a big fan of the flex fan but. I had one on my 75 square in high school and it did work ok for me and didn't overheat.

Flush it then see where you're at. I'm in Texas too so know how hot it gets here. Lol

If that doesn't help maybe call these guys and get them to build you one for your truck.

https://radiatorsupplyhouse.com/?utm_source={{campaign.id}}&utm_medium={{site_source_name}}&utm_campaign={{adset.id}}&utm_content={{ad.id}}
 

Bextreme04

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Any thoughts from anyone on my original question?

2 core, 3 core 4 core radiator?
Aluminum or 'stock' type?
Electric fans or stock fan?
Best place to order or have my original rotted out?

Thanks again for any help.

You should be totally fine with the stock radiator and setup you have unless you have bumped up the power output a lot or have a BBC in there.

The cheapest and easiest solution would be to take that radiator in to a good local radiator shop and have it fully rebuilt. You also NEED to put an overflow tank on there. The radiator is so plugged that the water pump is pulling all of the coolant out of the side the cap is on and nothing is making it through the radiator to replenish it. That is one of the worst plugged radiators I've ever seen, and that's saying something.

I bet that is why the spacer is on there, the PO was probably having overheating issues and they got rid of the fan clutch to try and help it out.

Here's my recommendation:
  1. Go down to the parts store right now and get a bottle of radiator flush and an overflow tank.
  2. Pour the flush in, top off the radiator and overflow tank with distilled water and drive it for a few days like that.
  3. Drain out all the coolant and flush fresh water through the block until it comes out clean.
  4. Take your radiator down to the local shop and have it rebuilt
  5. Get a new 195 thermostat
  6. Get the right fan clutch and replace the spacer with a fan clutch. The fan you have should be fine.
  7. Once everything is replaced, cleaned, and flushed refill with new coolant concentrate and distilled water in a 50/50 mix. NEVER use anything other than distilled water in a coolant system unless it is just for flushing the cleaner out. Those deposits are from someone running tap water in their system for a LONG time.

Also, if the radiator looks like that, I'm sure the heater core is probably just as bad. You might want to look at that while you have the cooling system drained for refreshing.
 

Bextreme04

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Also, I don't see the nipple on the radiator for the heater hose return and the trans cooler lines don't have anything running to them. Do you have an auto trans? Does the heater hose return go directly to the water pump?
 

75gmck25

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I'll post a picture of the Champion aluminum radiator I bought from Jegs for my '75 GMC K25 in 2018 (after I accidently punched a hole in the copper 3 row radiator). The old copper 3 row radiator worked fine most of the time, but with A/C on it spiked up to about 210+ in slow traffic at idle.

I have the aluminum radiator, a high flow water pump and 195 degree high flow thermostat, and stock steel fan with factory shroud and Hayden severe duty fan clutch. The heater return hose connects to the radiator. My RPO sticker shows that my truck originally had the factory HD cooling option.

In 90-95 degree weather I could start up the truck and turn on the A/C and it will idle for hours and never get above about 190-195. If I run it at 60-65 on the highway and then stop at a light it might spike up to 205 for a very short time as I first stop and it comes back to idle, but then the thermal clutch fan catches up and it goes back down to 195.

I would not recommend using electric fans, since the stock mechanical setup is so trouble-free once you get the right parts installed. However, if you do decide to go with electric I can also give you the Lester number for the 93 amp 12si alternator that could replace your original 10si.

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