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Re-core or replace RAD?


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Re-core or Replace Radiator?  

11 members have voted

  1. 1. Re-core or Replace Radiator?

    • Re-core
      3
    • Replace
      3
    • Eat a dick
      5


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You need good air flow and good coolant flow to transfer heat away.

 

Copper is a far far better conductor than aluminum, however aluminum is cheaper so just make a rad larger.

 

Air

Grill or fog lamps, bugs, leaves, dirt blocking air flow.

Gaps below the hood, around or under rad, holes in rad support for wiring allowing air to pass without going through rad.

Missing 'belly pan' allowing air under the vehicle.

Missing fan shroud which increases fan efficiency

Damaged fan blades

Oil leaked out of clutch fan reducing the drive force. Fan slips.

 

Coolant

Rad tubed crusted with hard water deposits reducing flow through them

Heater hoses connected around the heater, sending hot water back into the engine by passing the rad.

Soft lower rad hose collapses from pump suction at higher speeds.

Fan belt slipping

Rust scale formed by not using an anti freeze/coolant mix. 

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i had a 3 core stock style copper radiator with a healthy built L20b and couldnt keep it under 195

I replaced with an aluminum koyo and duel electric fans  WISH I DID IT YEARS AGO 

now it stays just under 180 on the freeway and fans never turn on till in traffic and it might get to 185 on a hot day 

i wanted the stock look but it wasn't enough radiator just my 2 cents 

That has not been my experience at all. The last street 510 that I owned and drove for years had a monster 2200 in it and a 3-row stock radiator. I had no problems keeping that engine cool. Even with the stock plastic fan and no fan shroud, it never overheated on me. It never ran hot either.

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In the '80s my truck was looking really ghetto, no front bumper, grill or pan... no license plate for like 15 years. I had rocks put pin holes in the rad a few times. It's more of a hassle to pull it and put it back than to solder the holes shut. One time it started steaming on the freeway. I made it ten miles home with shit all bubbling and hissing. A pretty good crack in a seam on the upper part. I didn't even pull the rad out... drained the coolant and torched the fuck outta it in place! Bake it dry with a torch, try to clean the joint, hose on flux and 50/50 acid core!!! Ran for years Ratsun as hell.

 

A while back I put a fresh head on the L16, so I figured I'd get a new rad too. The old guy at Beaverton Radiator wanted $375 for full-on, hot-set-up re-core job. He said it was not the OEM rad and that it was "rotten" and not worth fixing. He said replacements for the L16 are not available, only L20 rads. The difference is the top inlet is on the other side. You have to use an L20 top hose for the shape then cut half of it off. I think I had to relocate two of the mounting holes too.

 

A Ratsun Bro gave me an OEM L20 rad that was in great shape. I change my coolant and flush the system about every 4 or 5 oil changes. I would consider having an OEM L20 rad re-cored. Rather than the new unit he showed me lookin' kinda sketchy. I remember shopping for aluminum rads and you can send dimensions/drawings to get a totally trick Griffin racing radiator for about $400. 

 

When I swapped the L16s 35a alternator for L20s 60a... it's a bigger unit, so I was considering have a radiator made so that the lower rad hose wouldn't hit the Alt/Fan. It's a tight fit, but I made it work. Couple zip ties on the hose to the frame... Ratsun.

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A lot depends on the tstat, I have a 165 on mine with stock iodine rad, L18, no elect. Fans, no shroud and when it got really hot in the bay area several weeks ago, temp. Reading was 175 at stop light.

 

It should be running at 185F/190F fo , power and lower wear. You should be able to drive through Death Valley with the stock 185F thermostat and the radiator should be able to shed that heat properly. Try a 175F or a 180F sometime and you'll be surprised. Engines today and back when your truck was new were designed to run closer to 200F for best efficiency and lower emissions. 160F thermostats are used in 1950s and earlier engines.

 

Not saying this is the case with you, but for others, if you have to run a 160F on a stock engine in order to not run too hot then this is an indication of a cooling system problem. If running a modified engine or an engine swap then the rad is simply too small for it.

 

Here's another way to look at it.

 

 Two glasses of water in a 60F room. One at 80F and the other at 200F. Put thermometers in both and time how lone it takes both to shed 10F of heat. I guarantee the 200F glass will drop like a stone because the difference between it and ambient is so much greater. The same with rads. A hotter rad will shed heat faster than the same rad at a lower temperature.

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Got it back..not sure how people repair these things but it looks like the bent the fins in the corners to solder the leaks.  They spray painted the entire thing (well most of it), drain hose, pet cock and all.

 

Probably shouldn't asked them to paint it but won't even be able to tell once its installed...or I just go over it again myself.  

 

At this point as long as it doesn't leak I am cool with it. 

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It should be running at 185F/190F for, power and lower wear. You should be able to drive through Death Valley with the stock 185F thermostat and the radiator should be able to shed that heat properly. Try a 175F or a 180F sometime and you'll be surprised. Engines today and back when your truck was new were designed to run closer to 200F for best efficiency and lower emissions. 160F thermostats are used in 1950s and earlier engines.

 

Not saying this is the case with you, but for others, if you have to run a 160F on a stock engine in order to not run too hot then this is an indication of a cooling system problem. If running a modified engine or an engine swap then the rad is simply too small for it.

 

Here's another way to look at it.

 

Two glasses of water in a 60F room. One at 80F and the other at 200F. Put thermometers in both and time how lone it takes both to shed 10F of heat. I guarantee the 200F glass will drop like a stone because the difference between it and ambient is so much greater. The same with rads. A hotter rad will shed heat faster than the same rad at a lower temperature.

...thanks mike, will consider your suggestion.

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Get pre-mix anti-freeze/coolant or mix 50/50 yourself.The left over save in a sealed container* for top ups.  If you do not have a coolant recovery system (you should do this) leave an inch and a half space at top of the rad for expansion.

 

Be sure to build a coolant recovery system. You need a later rad cap with the double spring and seal, a longer rubber hose and a container. I use the coolant recovery container from a 720 for my car. It looks correct and bolts to the inner fender. Any thing will do, a plastic water bottle or large energy drink can as long as it's secure. Make sure the hose goes to the bottom and it's half full with coolant mix. Any time the rad burps coolant out, the container saves it till the rad cools and the air inside contracts, it will siphon back in. Now I top up once a year.

 

 

 

*This is sweet tasting and will kill pets and kids in a most horrible way.

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If you have an unknown amount of water in the block right now, and the system holds 7 liters, divide in half = 3.5liters. This is how much full strength anti-freeze to put in. Now top up with distilled water.

 

Ahh I see mid Atlantic. Can I assume continuously below freezing weather? A 70/30 mix wouldn't hurt. Just put the full 4 liters in and top up with distilled water. 

 

Why distilled? Because it does not have dissolved minerals in it like tap water. In a cooling system water goes in and slowly boils away and minerals collect and consentrate.... in the rad core.

 

 

 

Get pre-mix anti-freeze/coolant or mix 50/50 yourself.The left over save in a sealed container* for top ups.  If you do not have a coolant recovery system (you should do this) leave an inch and a half space at top of the rad for expansion.

 

Be sure to build a coolant recovery system. You need a later rad cap with the double spring and seal, a longer rubber hose and a container. I use the coolant recovery container from a 720 for my car. It looks correct and bolts to the inner fender. Any thing will do, a plastic water bottle or large energy drink can as long as it's secure. Make sure the hose goes to the bottom and it's half full with coolant mix. Any time the rad burps coolant out, the container saves it till the rad cools and the air inside contracts, it will siphon back in. Now I top up once a year.

 

 

 

*This is sweet tasting and will kill pets and kids in a most horrible way.

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There is a block drain plug above the starter, (L-16) that if removed. will drain the block. 

If you put both radiator hoses on the engine, you can put a garden hose into the bottom one, and flush any crud out of the engine.  I use the top hose to direct cruddy water away from the engine.

If while flushing the block, you remove the block drain plug, and blow compressed air into that hole, it will stir up a lot more sediment., and expel it out of the engine block.  Put your thumb over the hole, let the block fill again, blow air in to the hole again.  Repeat until the water comes out mostly clean.

Flush the heater core also.  Flush in on the bottom heater connection, this will tend to move crud away from the heater water valve.

 

Best price on antifreeze, is Walmart.   Buy a gallon of 50/50 mix, a gallon of full strength, and walk over to the grocery section, buy a gallon of distilled water.  Empty the 50/50 gallon in to the radiator, and then fill that container half full with the full strength antifreeze.  Put half of the distilled water, into the two half empty antifreeze containers.

With the block drained, the heater core drained, you will put close to two gallons of coolant into the engine.  When filling the radiator, park the truck with the front end uphill, and have the heater valve open.

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.... and heater core. Not just the sediment but heat is improved. I had a 521 in Ontario that said it was warmed up but it was bloody cold in the cab. I reverse flushed a cup of tarry pellets that some previous owner put in the rad to stop a leak. I think it was called 'Bar'sLeak' .

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I bought the prestone 50/50 (Target $9 a gallon) shit and poured a gallon in, ran it with the rad top off until it started running.  Turned the truck off it burped some out, I topped it off put the rad cap back on and called it a day.  Drove to the dump to drop some lumbar off and the entire time was wondering what was going to break next.  

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I bought the prestone 50/50 (Target $9 a gallon) shit and poured a gallon in, ran it with the rad top off until it started running. Turned the truck off it burped some out, I topped it off put the rad cap back on and called it a day. Drove to the dump to drop some lumbar off and the entire time was wondering what was going to break next.

, then I check the next day just to make sure.
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