Bigger Radiator

Post by **HenryJ** » Sun Oct 06, 2002 8:23 pm

As most of you know, I installed the Go/Dan Ind. # 43 1405 replacement radiator.

It has a 1 3/8" core.

The stock one is a 1" core.

It works great, tested in the desert (dry creek expedition), so far. Seems to run steadily about 5* cooler than stock.

I did have to go back to the stock thermostat. I had been using the 180* Jet stat, but with the larger resevior of cold coolant it would open too soon and cool the engine at the time the PCM was expecting the engine to have warmed to it's minimum threshold limit, setting the SES light (code PO128) , or near as I can tell.

So...moral of the story: If you plan on going to the bigger radiator- don't waste your $ on a colder thermostat. IMHO

Steven · Post by **Steven** » Tue Oct 08, 2002 5:50 am

I've got the radiator installed with the 180 stat, and so far no SES light. I'm crossing my fingers. It was pretty warm this weekend 85degrees, running the Air conditioning and pulling the camper. The temp never got over 195. That made me happy!. I may try the electric fan again and see what happens next summer.

a2b · Post by **a2b** » Tue Oct 08, 2002 7:24 pm

ya, i will need that bigger radiator. sometimes i over hear just sittin in the hot sun. i hate that! if yall have any problems with the radiator, let us know

Post by **HenryJ** » Fri Mar 14, 2003 7:01 pm

Thought I'd add a link to the thread in the old forum: Bigger Radiator

goodtimes · Post by **goodtimes** » Sat Mar 29, 2003 12:04 am

HenryJ wrote:As most of you know, I installed the Go/Dan Ind. # 43 1405 replacement radiator.

It has a 1 3/8" core.

The stock one is a 1" core.

It works great, tested in the desert (dry creek expedition), so far. Seems to run steadily about 5* cooler than stock.

I did have to go back to the stock thermostat. I had been using the 180* Jet stat, but with the larger resevior of cold coolant it would open too soon and cool the engine at the time the PCM was expecting the engine to have warmed to it's minimum threshold limit, setting the SES light (code PO128) , or near as I can tell.

So...moral of the story: If you plan on going to the bigger radiator- don't waste your $ on a colder thermostat. IMHO

If your thermostat is working properly, it doesn't matter how big your radiator is. The thermostat will regulate the temperature of the coolant, not the radiator.

I ran numerous tests on my zr2 while doing some research into a larger radiator (was planning on a custom 3-row aluminum Howe core). With a working thermostat, I could achieve up to a 80 degree temperature drop across the radiator under certain conditions (read via a NIST tracable calibrated thermometer and a series of 8 thermocouples in the cooling system). If your thermostat is designed to maintain 180 degrees, and your coolant temp is below that threshold, then the thermostat will start to close, restricting the flow out of the engine....so the coolant spends more time in the block/heads, it will heat up more. As the coolant temp (measured at the thermostat) approaches 180 degrees, the thermostat approaches its fully open position.

Post by **HenryJ** » Sat Mar 29, 2003 8:03 am

goodtimes wrote:
HenryJ wrote:
It works great, tested in the desert (dry creek expedition), so far. Seems to run steadily about 5* cooler than stock

If your thermostat is working properly, it doesn't matter how big your radiator is. The thermostat will regulate the temperature of the coolant, not the radiator.

If your thermostat is designed to maintain 180 degrees, and your coolant temp is below that threshold, then the thermostat will start to close, restricting the flow out of the engine....so the coolant spends more time in the block/heads, it will heat up more. As the coolant temp (measured at the thermostat) approaches 180 degrees, the thermostat approaches its fully open position.

I agree with everything you posted

You left out that once the temp rises beyond the threashold of the thermostat, the (wide open flow) your temperature is then regulated by the radiators ability to cool the coolant. If there is insufficient dissapation of the heat that is when boiling over becomes a problem.

We had record heat that summer and my cooling system was unable to keep up, even with adequite air flow (highway driving). I had been consistently running on the edge of overheating. By the stock guage( agreed to be uncalibrated and much less than accurate) 210* It was beyond the thermostats ability to regulate anything but wide open flow. By increasing the reservoir of coolant and the surface area of the radiator it was able to dissapate more heat and keep me just under that boiling point.

It doesn't "seem" right but during the really hot weather it will run 5* cooler than the stock radiator.

During normal temps, it does exactly as you relayed above and maintains the 195*-200*.

The SES light problem using a cooler thermostat is just a timing issue for the PCM (the 2001 is very sensitive). The cooler stat would open for the first time sooner, which drops the engine temp as the cold coolant enters right at the time the PCM expected the temp to be at it's minimum threashold. This is done to warn of a stuck thermostat. The gauge in our trucks is not sensitive enough to show the temperature drop when the thermostat opens the first time.

The system in my HenryJ is and it is very apparent when the thermostat opens. So some of the diagnosis for the trouble code was done using experience.

P.S. Brian Welcome aboard

Glad to see a former Zr2 owner/ new Jeeper here

goodtimes · Post by **goodtimes** » Mon Mar 31, 2003 10:52 am

HenryJ, I was not aware of the PCM issue on the '01s. I never changed my 'stat out due to the increase in tailpipe emissions and relatively little increase in performance recieved by dropping the coolant temp 20* (well, that and mine was constantly running hot (210+) anyway, so it wouldn't have stopped that problem.

Using the thermocouples I had installed along with the digital thermometer, I could tell exactly when the thermostat opened (well, within a few seconds anyway). All the data that I collected supported the dealers claims that the cooling system was working as it was designed to. But it also showed a inadequate capacity (or design flaw as I put it to GM).

The coolant was moving through the radiator too darn fast for it to be cooled off. By going to a larger (thicker) radiator, you will gain some help via the increased surface area, but will be minimal if the cooling system is working as it was designed to (the temp difference from the surface of my radiator core to the air temp on the engine side of the radiator was less than 15*f -- so the core was dissapating all the heat it could). The big advantage you should see is due to the reduced velocity of the coolant through the radiator. Basically, because the coolant spends more time in the radiator, you are able to move more units of air over each unit of coolant. So your inlet temp (to the engine) will be lower, which, ideally, would let your thermostat start doing its job again, rather than sit wide open all the time (like mine did about 90% of the time).

Unfortunately, due to space restrictions in the S-10's, we don't have alot of options, unless you go to a slim line electric fan. I was running a flex-a-lite #210 (dual 12" pullers, 1250cfm each), which BTW, fit the OE core beautifully. It is like they were made to fit that radiator.

Superchargedcrew · Post by **Superchargedcrew** » Mon Apr 07, 2003 8:06 am

I haven't tried a new radiator yet but I put in a 160* stat in and yes my ses light is on but nothing a small piece of black electrical tape wouldn't fix. I has kept my engine temp to 190*sitting still with ac on in 95*+ weather. Because soon as you get moving it drops back down to the 160* mark. My truck is also producing over 310hp when I'm getting on it. I had it dyno tested at Summit Racing Store in Tallmadge Ohio. I want to put the bigger radiator in but I don't think I have the room.

a2b · Post by **a2b** » Mon Apr 07, 2003 9:51 am

Superchargedcrew wrote:I haven't tried a new radiator yet but I put in a 160* stat in and yes my ses light is on but nothing a small piece of black electrical tape wouldn't fix. I has kept my engine temp to 190*sitting still with ac on in 95*+ weather. Because soon as you get moving it drops back down to the 160* mark. My truck is also producing over 310hp when I'm getting on it. I had it dyno tested at Summit Racing Store in Tallmadge Ohio. I want to put the bigger radiator in but I don't think I have the room.

310hp, wow, whats that like? i have thought about doing that. so how is your gas mileage? wores or better?

Superchargedcrew · Post by **Superchargedcrew** » Mon Apr 07, 2003 12:40 pm

Actually I still get good gas mileage, if I can stay off the gas pedal. Here is one of my little quarks I get a kick out all these fast and furious wanna be cars, and I end up racing them light to light on a regular basis because I want them scratching there heads when they can't figure how my s-10 crew 4x4 either beat them or stayed side by side with them. Because it will take NOS for most of them to get around me now..[/img]

Conman · Post by **Conman** » Mon Apr 07, 2003 1:42 pm

HenryJ wrote:As most of you know, I installed the Go/Dan Ind. # 43 1405 replacement radiator.

It has a 1 3/8" core.

The stock one is a 1" core.

It works great, tested in the desert (dry creek expedition), so far. Seems to run steadily about 5* cooler than stock.

I did have to go back to the stock thermostat. I had been using the 180* Jet stat, but with the larger resevior of cold coolant it would open too soon and cool the engine at the time the PCM was expecting the engine to have warmed to it's minimum threshold limit, setting the SES light (code PO128) , or near as I can tell.

So...moral of the story: If you plan on going to the bigger radiator- don't waste your $ on a colder thermostat. IMHO

Henry, if you had to do it over again, would you go with the radiator or just go with a Jet Stat 180? Also, is there a radiator that's larger than 1", but smaller than 1 3/8" that might work better with the 180stat?

Cheers,

Con

Post by **HenryJ** » Mon Apr 07, 2003 5:21 pm

I'd definately do the radiator. The cooler stat wasn't going to solve the problem for me. During the record heat we had last summer I couldn't get it to cool down even on the highway. Therefore the cooling system was inadequate. A cooler stat would have delayed the heating a little , but would not solve the problem.

The threshold for the SES light is to warn of a stuck thermostat, it just happens that the timing is such that the cooler 180* stat opens and floods the engine with yet unheated coolant at the time the PCM expects it to have reached a higher operating temp.

It is just a timing issue with the over sensitive 2001 PCM.

If there was a way to delay the PCM threshold timing, or alter it's coolant temp reading , this could be solved.
EDIT: Solved this timing issue later by relocating the IAT. It is also a good idea to consider what needs to be done to match the fans engagement temperature to match the stat.

Mine has been operating rock solid at the 200* mark on the stock gauge. With the old radiator it would creep over a little (5* or so)

I'd be careful running the cooler stat with the SES light on. The engine may try compensating to warm the engine. (I have not confirmed this, though)

P.S. Don't worry about the additional 3/8" creating problems. Of the extra core thickness 1/2 goes forward. The space between the condensor and radiator is reduced by 3/16". It is a direct replacement radiator.

This is the stock compared to the new one.

3/8" doesn't sound like much, but that is 3/4" more surface area per tube. Multiply that times the number of tubes and it does add up

Post by **HenryJ** » Sun Jun 01, 2003 6:57 am

Now that summer temps are back , I have been getting some renewed interest in the bigger radiator, so I thought I'd add a little update.

Go/Dan is a subsidiary of , or was bought by Transpro the radiator still has the same part # 431405 under the name Ready-Rad - Catalog

Here's the spec page

Post by **HenryJ** » Wed Jul 13, 2005 5:00 pm

It has been almost three years since I installed the bigger radiator, and made the change to green coolant.

Finally today I found time to flush the system and put in fresh.

I know I am way overdue, but I am probably ahead of some of you

The coolant was slightly opaque, but really looked pretty good. The radiator looks really good with only a slight film on the trans cooler. The overflow/expansion tank did have some "muddy like" sediment in the lowest portion. This is why you must pull the tank and clean it.
I can only surmise that it may have been as result of the presence of residual dexcool in the system.

I drained the radiator then, after running the engine and flushing until the system ran clear, this time I pulled block water jacket plug. This is behind and below the left side freeze plug. Where the stock freeze plug heater is located. I found that an 18" 3/8" drive extension, universal, 14mm socket and rachet worked the easiest. I inserted it between the frame and torsion bar from behind the front suspension. It came out pretty easily, and did drain almost another gallon. Be sure to use some thread sealant before reinstalling.

I added a bottle of Redline Water Wetter, a gallon of green and a gallon of distilled water. Then filled the expansion tank with about three quarts of 50/50 mix.

Good to go for couple years now

F9K9 · Post by **F9K9** » Fri Jul 29, 2005 7:03 pm

Ok, my Transpro radiater is enroute and should be here Tuesday. I am going to pick up hoses and clamps tomorrow and/or Monday.

Besides new green coolant, water wetter and extra ATF, I would like to toss in a tranny cooler since it seems like an appropriate time to do it with the rad pulled.

I want to skip the tranny rubber hoses and do the tranny cooler connections on the lower rad. I have zip experience with bending tubing, flanges. flaring and have no tools to perform such tasks. I am not wild about being ripped off and would like to try to do this myself if, the tools can be borrowed from Advance or purchased relatively cheaply.

Suggestions, opinions, instructions and advice is welcome

F9K9 · Post by **F9K9** » Tue Aug 02, 2005 2:42 pm

Okay, radiator was sitting at front door when I arrived home tonight. During lunch I picked up a medium duty Hayden transmission cooler at NAPA. I was reviewing GM techline's instructions for radiator replacement and they mentioned completely removing the oil cooler lines, oil filter mount and replacing seals when reinstalling. Is all this necessary or is there enough movement in the lines to just loosen them up and move them far enough to remove the old radiator?

I just would like to have everything in place come Sunday morning.

Post by **HenryJ** » Tue Aug 02, 2005 2:51 pm

f9k9 wrote:... is there enough movement in the lines to just loosen them up and move them far enough to remove the old radiator?

There is room enough.
I didn't replace any seals when I did mine.

Make sure the adapters/fittings are all of correct size and accounted for. A tube of Permatex #2 to be used as thread sealant should be on hand.

If you want to add an engine block heater for the winter time now would be a good time since you're draining the system. I paid $15 for mine.

F9K9 · Post by **F9K9** » Tue Aug 02, 2005 4:05 pm

Thanks, Brule

Will the permatex #2 work on the block drain plug(s) as well?

Seems to me that I was doing a little research on techline awhile back and there is one on the passenger and one on driver's side of the block but, am probably wrong.

Glancing at the radiator I didn't notice any parts that came extra other than for the traany lines and they were not plugs. I guess if you own a five speed that they assume you remove the plugs off of your old radiator.

Post by **HenryJ** » Tue Aug 02, 2005 7:35 pm

f9k9 wrote:...Will the permatex #2 work on the block drain plug(s) as well?

Yes

Seems to me that I was doing a little research on techline awhile back and there is one on the passenger and one on driver's side of the block but, am probably wrong.

You may be right, but it may be behind the starter on the right side, and not very accessible.

Glancing at the radiator I didn't notice any parts that came extra other than for the traany lines and they were not plugs. I guess if you own a five speed that they assume you remove the plugs off of your old radiator.

If you have a five speed you can leave the lines open. I'm betting the transmission fluid won't flow

You could plug them to keep it clean, but some silicone would take care of that.

F9K9 · Post by **F9K9** » Tue Aug 02, 2005 7:43 pm

Ok, I deserved that and I suspect you sat on your hands for months to deliver that response.

In any event.....thanks for your time and advice

Post by **HenryJ** » Tue Aug 02, 2005 7:51 pm

f9k9 wrote:Ok, I deserved that ...

Nah, just think of us as Abbott and Costello (sp?) I'm not sure who is who. Wait a minute isn't he on first!

Remember there are no stupid questions, only stupid people who do not ask questions.

We all learn, even though it is sometimes things that we already knew

F9K9 · Post by **F9K9** » Wed Aug 03, 2005 4:35 pm

Brule,

How much oil and tranny fluid did you lose on the rad mod?

As I talked about in a topic somewhere

. I am replacing hoses with the rad switch. The hoses better be better than the ones in the good old days when two gates hoses were over $50

Post by **HenryJ** » Wed Aug 03, 2005 5:02 pm

f9k9 wrote:...How much oil and tranny fluid did you lose on the rad mod?

I don't recall losing enough to worry about.
The sandwich coolers in the radiator are really pretty small.

If I were to guess...maybe 8 oz each? Not much.

Don't worry about adding any until after you get the install done , warmed and checked for leaks. Then let things cool off / drain back, and check the levels.

F9K9 · Post by **F9K9** » Wed Aug 03, 2005 6:12 pm

Am all set. Just wish my Saturday was not already planned out for me. Three saturdays in a row shot.

No wonder I had a smile on my face for fifteen years as a single man

Post by **HenryJ** » Wed Aug 03, 2005 6:19 pm

f9k9 wrote:Am all set. Just wish my Saturday was not already planned out for me. ..

It is always a struggle between time and materials. When you have the time, you never have everything that you need. Then when everything is available, the time to work has gone away

Good luck and give us a "blow-by-blow" on how it went

F9K9 · Post by **F9K9** » Wed Aug 03, 2005 7:13 pm

I may try the pic routine and will keep you posted

F9K9 · Post by **F9K9** » Sun Aug 07, 2005 3:14 pm

Larger radiator and transmission cooler was installed today

It was pretty straight forward and as usual Murphy was nearby and made the install go ugly at times

I bet a lot of you have blacktop or concrete driveways and take them for granted

I hate looking for small "one of a kind" parts in the freakin' gravel

I had a couple small questions come up but, I was lucky and got the needed answers for them

The tranny cooler is very easy to do when combined with the larger radiator mod. I went with the connections to the lower part of the radiator and with the battery and tray pulled it was even easier.

I only sliced one thumb on sheet metal before I put my mechanic gloves back on

I didn't take pics because Mrs Wetter decided that she may need the truck in three hours after I asked her yesterday it she needed it because of the install and that I wanted the truck cold.

So after I was firmly involved she called my cell ph which was no where near my location under the crew and hitting my head to get to it.........She said "nevermind, I don't need your truck"

Post by **HenryJ** » Wed Oct 05, 2005 3:41 pm

Go/dan , Transpro, ReadyRad was bought out by Modine and now has become Proliance.

Here is a good price on the radiator - RockAuto radiator

crew cab sonoma · Post by **crew cab sonoma** » Tue Oct 24, 2006 7:44 am

did anybody happen to notice where these radiators are made? i talked to a local radiator shop, and they said to stay away from Proliance, because it was cheap imported stuff, and the 1 3/8" core didnt offer any better cooling than the original 1' core, because of fewer cooling fins per inch.

i`m considering buying one, and was wondering if any of you can confirm or counter any of what i heard from this shop? nobody has one in-stock locally, so i cant verify myself.

my original rad. is partially clogged, and im weighing my options as far as getting mine cleaned out, or getting a new one. i would prefer the thicker core, if it really offers an improvement, as im considering installing a V8 someday.

F9K9 · Post by **F9K9** » Tue Oct 24, 2006 11:49 am

You might want to check out this thread and it's links from TXZR2

crew cab sonoma · Post by **crew cab sonoma** » Thu Oct 26, 2006 5:43 am

thanks for the link.
turns out my local Autozone did have this radiator in stock.
its made in Mexico, but GM probably builds them there too...
but the fins per inch looks about the same as the original one.
normally $218, i told them if they could match Rock auto`s price of $148, i`d buy it... they dint even hesitate...

but during the install, Murphy dropped by for a visit on me too...
the new rad. has a smaller thread size for the tranny cooler fittings than the original, but they (Ready-Rad) did provide the correct adapters for this.
the problem is, with the adapters installed, the factory adapter with the clip that retains the cooler line is now about one inch farther back, so the cooler line must be bent slightly to align properly.

i didnt see any type of O-ring on the line, or the fitting, and i dont really see how this thing would seal well without one. but i installed it anyway, and sure enough, its leaking.

is there supposed to an O-ring, or other type of seal on the end of the tube?

F9K9 · Post by **F9K9** » Thu Oct 26, 2006 7:23 am

I honestly don't recall if, it did or not. Sorry

crew cab sonoma · Post by **crew cab sonoma** » Fri Oct 27, 2006 4:35 am

i found the problem. it was me...

i didnt tighten the factory fitting into the adapter...

and inspection of the factory fitting reveals it does indeed have a captured O-ring inside it, to seal against the tube. its not easily seen if you dont look closely.

everything is now tight, and leak free...

Post by **HenryJ** » Fri Oct 27, 2006 4:53 am

crew cab sonoma wrote:did anybody happen to notice where these radiators are made? i talked to a local radiator shop, and they said to stay away from Proliance, because it was cheap imported stuff, and the 1 3/8" core didnt offer any better cooling than the original 1' core, because of fewer cooling fins per inch...

That may have been a "blanket statement" with out direct knowledge of the radiator in question. "Imported" is not synonymous with bad. Most of the parts are no longer manufactured in the US.

Fin count is a good indicator and something to watch for. The tube width is as important or more so. There is just no substitute for the increased surface area in contact with the coolant.

In the case of the plastic tanked radiators, they are not all created equal. If you get a chance set several different brands side by side for comparison.

My local radiator shop took the time to do this for me when I was researching the extra capacity replacement. The thickness of the reinforcing web and number of them can be a key indicator of the strength. There are many "substandard" tanks being used. Some are on brand names that you would think should be of the highest quality.
Use your own judgement. The stock radiators are pretty decent. Just too small. the tanks seem to hold up pretty well though. When comparing , use them as a standard to meet or exceed.

crew cab sonoma · Post by **crew cab sonoma** » Fri Oct 27, 2006 6:02 am

HJ, i agreee.
thanks for all the info. i wouldnt have even known about this thicker core radiator without this site.

my local Autozone had the Transpro/Ready-Rad 431405 in stock, but they didnt have any other comparable brands on hand.

that seems to common for most places, they stock only one brand of "big ticket" items, but can order other brands. but understandably, they wont order them just so you can compare them.

i did find a Koyo brand stock replacement at another store, but it was only 1" core, like original.
it was made in Indonesia.

Post by **HenryJ** » Fri Oct 27, 2006 9:36 am

crew cab sonoma wrote:...common for most places, they stock only one brand of "big ticket" items, but can order other brands. but understandably, they wont order them just so you can compare them.

True.
That is one reason I use the stock GM radiator as a "standard to meet or exceed"
In my comparison the stock tanks were really pretty good. Now add a thicker core and you really have something.

Another thing to watch out for is that one company buys another and substitutes inferior parts while using the known brand name. The reverse may be true as well a company with a bad product buys one that has good stuff.

That is where you must keep your eyes open and make your own decision on the quality.

crew cab sonoma · Post by **crew cab sonoma** » Mon Oct 30, 2006 5:58 am

one more thing ive noticed. every time i have drained my cooling system, on both of my trucks, i have heard "gurgling" noises through the heater core, which i believe to be air trapped in the core.

usually after getting the engine to 3000 rpm a few times, the noise tends to go away.

but the Ext. Cab seems to need a couple of WOT visits to 5000 rpm to eliminate this noise, as driving around for a few days with the new radiator, you could still hear this noise when i got to 2500 rpm or more. finally, last night, i gave it a few WOT passes.
now the noise is finally gone...

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