Cooling system plumbing type and size

[MTPyle]

So one of the things we have had on our list is to upgrade our cooling lines on our truck. Not a lot of conversation on here about the pros and cons for hard lines vs hose lines.

Originally it had almost all steel hard lines but we changed to aluminum in the tunnel and up in the engine area leaving the steel down low where it can get hit with rocks.

We are thinking of going to AN braided lines for simplicity and less points of failure. Currently we have a crap ton of silicon and hose clamps.

One of the challenges is we need sensors in the line so we will need to machine a custom sensor tube in the output side.

We were going with -20 steel braided on the suction and -16 poly braid (for weight) on the pressure side. But after talking to Meziere we are going to use -20 on both sides. Currently we are 1 1/4 on both sides so I don't want to go less and make our flow worse.

Each side will be about 13ft of lines and at least 2 90 fitting on each side.

Has anyone used hoses instead of hard line? The parts are more for hoses but less labor so I think hoses will be cheaper and in theory better flow.

Here is a pic of all our lines out of the truck. LOL what a mess. You can see why its been on our list of upgrades.

Also I think our radiator was plumbed backwards. We jsut left it the way it was from when we got it and the output of the engine was going to the bottom of the radiator. No wonder it was so hard to get air pockets out.

Mike

 

[Gfo_prep_fab]

We have done both. Most trucks we build we use the aluminum tubing. We have also used aluminum an weld bungs on the tubing to then use an lines. 1.25 lines seems pretty small for a 6100. Another question is where are you filling the radiator from? Do you have a surge tank or cap on the radiator?

 

[Slippery P]

-20 on the inlet and -16 on the outlet is fine.

 

[MTPyle]

-20 on the inlet and -16 on the outlet is fine.

I agree but after talking to Jerry at Meziere he has me worried. And we basically have -20 on both now. So it would stay the same.

GFO

we have a tank above the radiator in the rear with cap. Here is a pic.

Our radiator is out getting flushed and tested before we weld the AN fittings on. We have a backup radiator so have to do both of them.

Mike

 

[McCredie A]

This is a question. Should you flush and test the radiators after the AN fittings are welded on?

 

[MTPyle]

Good point. Haha

But too late. Can’t weld them in until next week and they are already getting flushed and tested.

But we will do our own blow out and flush before on them and the lines.

Mike

 

[Gfo_prep_fab]

Your surge tank looks low. Is your radiator low as well?

 

[jon coleman]

does the water come right out of eng.and go directly to radiator, ie no swirl tank/ 'burp' line?, water out of an eng at speed is quite angry, its good to settle it, burp it/ and have solid water enter the radiator

 

[MTPyle]

Your surge tank looks low. Is your radiator low as well?

Yes our radiator is low, it’s out of the air flow and has a air scoop.

The expansion tank is well above the radiator and above the engine.

We have had this set up since we had the LS3 over 3 years ago. It’s worked pretty well when we get the air out and don’t pull the thermostat without blocking the bypass. Haha

Our temps are around 210-230

Mike

 

[AZ7000']

With the low radiator mount with the scoop do you see any difference in temps when following a golf cart vs a "heavy" vehicle?

 

[green787]

The output of the water pump goes to the bottom inlet of the radiator in order to purge bubbles..... The top of the radiator outlet goes to the thermostat.....

 

[MTPyle]

The output of the water pump goes to the bottom inlet of the radiator in order to purge bubbles..... The top of the radiator outlet goes to the thermostat.....

Uh that’s not what most radiator guys say.

Then you are sucking air into the inlet. If you pull from the bottom you always have a clean fluid source with no air. And heat rises so in theory the bottom is cooler.

 

[MTPyle]

That is SO freekin' wrong....!!!! And the opposite of what every car ever built has..... Think about it.... the output of every water pump out of Detroit takes a 90 degree bend and goes right to the bottom INLET of the radiator..... No wonder you have cooling issues.... major air pockets.... impossible to purge.....
Those aluminum water pipes shed a lot of heat as they go back and forth to the radiator and engine..... Braided line will not shed heat.... Dumb idea....

Well actually I think we are pulling from the top right now which I believe is wrong and all the race radiator guys say pull from the bottom.

You are telling me I will have less air pulling from the top? What planet do you live on. Air rises in water on Earth. Not the other way around.

But you can run yours any way you choose. Or keep it stock which I know you love.

I will call CBR who makes our radiator and make
Sure. I will let you know what they say.

Mike

 

[FourLow]

 

[jon coleman]

some radiators dont have a cap,,, then what??

 

[jon coleman]

big hose bottom of radiator>water pump>engine block>head>thermostat/ restrictor>top of radiator, back through the loop again.simple version.here, ill post again, the pointy arrow going out of radiator after pump is the big -20 hose out of the bottom of radiator, then you see the hose into the swirl pot , thats from Out of the top of engine at the thermostat/ restrictor housing, where i like to put the temp sender& bleed line to expansion tank, -3( top radiator bleed hose-4,when there is no cap, on a stock set up, i plumb the heater outlet, which is Now the expansion/ header tank outlet to water pump inlet& block off or run a bleed to header tank

 

[green787]

OK, I may have been wrong on this one..... It happened once before....

 

[green787]

If I had long tubes going to radiators behind the cab, I would run the inlet at the bottom in order to automatically purge any air to the recovery tank.... IMO...

 

[jon coleman]

inlet to bottom?, but now your ' pulling water back IN through the Top of radiator, has to flow other way, also pulling air back in from the bleed hose hooked into Top of radiator to the header/ expansion tank, you want to pull the water at Loooowest point, air has a hard time being pulled down, thats what the swirl pot does , it makes it impossible for air to get passed & into radiator , it burps out the top -3 line to the header tank

 

[jon coleman]

OK, I may have been wrong on this one..... It happened once before....

View attachment 244590

heater return hose is what is hooked up to expansion tank/ header tank,heater feed is blocked or turned into a -3 bleed to header/ expansion tank