Help cooling 408 stroker

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if you live somewhere where it's regularly 115 degrees we need to start another thread on why you would live in a place that's regularly 115 degrees...
by regularly i'll say a few days each summer.
last sunday it hit 120.7 at my house, to which we say "welcome to Phoenix" :lol:
 
Grab yourself a one of the high performance SPAL twin fan set-ups with controller and twin 40 amp relays. They will clear your water pump and dramatically outflow your current single fan set-up.
 
Grab yourself a one of the high performance SPAL twin fan set-ups with controller and twin 40 amp relays. They will clear your water pump and dramatically outflow your current single fan set-up.
Like I said though if his cooling system isn't up to keeping his temperature down and the study 40 miles an hour and up those fans aren't going to do anything for him ultimately. If they do they're a Band-Aid for an inferior cooling system...
 
I tried the champion shround/fan assembly, a flex a lite high output, and finally an HHR fan. I have a magnum based 408 with a high flow pump, 180 'stat, champion 22" radiator, etc. All brand new. My car would idle all day in 100 degree temps at ~185 max. But it would slowly overheat with city driving and QUICKLY overheat on the highway. Ive had it at 240 degrees before i got stopped.

I've tried 50/50 mix, 50/50 with water wetter, straight water with water wetter, etc. I tried it with a stock pump and high flow pump.

I finally restricted the HUGE 1" bypass hose and put a 3/8" hose on it. That in theory forces more water through the rad. And reduces the hot water recycling back into the engine. My car runs 200 max now on the highway after some hard runs.
20200723_182211.jpg
 
I finally restricted the HUGE 1" bypass hose and put a 3/8" hose on it. That in theory forces more water through the rad. And reduces the hot water recycling back into the engine. My car runs 200 max now on the highway after some hard runs.

That's really interesting and almost amazing. Never thought of that but it does make sense. One thing I would add is that I'm a huge fan of engine oil coolers. They can pull out a lot of heat as well.
 
I put in a the electrical fan with a switch because it was heating up with the mechanical fan in stop and go traffic. I figured its not enough CFM but i have so little space dont know what to do.

I was thinking of getting a 2nd electrical fan as a pusher for the front side of the radiator and just offset both fans?

Did you run a shroud with your old mechanical fan system?

I run that Champion 4-row radiator

I don’t think they sell a good mechanical fan shroud because the radiators are so generic. ??

I made my own. AND I run a cut down by 2” diameter MP fan kit. Yes 1” cut off the widest part of the blade. That’s because the early Champion radiator had the top hose too near the center of the radiator tank and it interfered with std diameter fan. Later I had it moved over, but kept the cut down fan (more HP)

Like was brought up previously, I METICULOUSLY, cleaned the water passages of my block. Hot tanks nowadays are weak. And even though, you gotta get in there and pick it clean. Coat hangers, wire, tiny flashlights, hose picks, screwdrivers... you name it.

No issues for me.

Also, in So Cal you don’t need Anti Freeze. Run distilled water and 1 bottle Justice Brother Radiator Super Cool and 1 bottle Justice Brothers Radiator Protector.

I’ve got 8 years on my 340 stroker (416)
 
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I tried the champion shround/fan assembly, a flex a lite high output, and finally an HHR fan. I have a magnum based 408 with a high flow pump, 180 'stat, champion 22" radiator, etc. All brand new. My car would idle all day in 100 degree temps at ~185 max. But it would slowly overheat with city driving and QUICKLY overheat on the highway. Ive had it at 240 degrees before i got stopped.

I've tried 50/50 mix, 50/50 with water wetter, straight water with water wetter, etc. I tried it with a stock pump and high flow pump.

I finally restricted the HUGE 1" bypass hose and put a 3/8" hose on it. That in theory forces more water through the rad. And reduces the hot water recycling back into the engine. My car runs 200 max now on the highway after some hard runs.
View attachment 1715593791
This could be one of the reasons that I don't have as many problems as most because I did not run a heater at all or a bi-pass... Or a thermostat... Just a gutted one.. distilled water with a bottle of redline water wetter...
 
Well I changed out the water pump to a high flow, have a champion 2 row radiator, and 3000 CFM flex a lite fan. So I will see how it goes when I install everything over this weekend.
 
Well I changed out the water pump to a high flow, have a champion 2 row radiator, and 3000 CFM flex a lite fan. So I will see how it goes when I install everything over this weekend.
IMHO you are not there yet.
Try it, then we'll talk
Best of luck
 
Finally had 2 spal fans, 2 spaw relays, and went with 50% antifreeze 50% distilled water with a bottle of water wetter. Can seems to be running cooler ran around 210 out here in Cali while its 99 degrees outside right now.

20201015_130314.jpg


20201015_130300.jpg
 
Finally had 2 spal fans, 2 spaw relays, and went with 50% antifreeze 50% distilled water with a bottle of water wetter. Can seems to be running cooler ran around 210 out here in Cali while its 99 degrees outside right now.

View attachment 1715613483

View attachment 1715613484
Some would say that 210 is OK
For me that is still way to hot.
You did not answer my questions from post #38
I cant give you any help with out more info.
That water pump pulley looks very large in diameter, that's part of your problem.
 
Some would say that 210 is OK
For me that is still way to hot.
You did not answer my questions from post #38
I cant give you any help with out more info.
That water pump pulley looks very large in diameter, that's part of your problem.


MC2374 Radiator Dimensions:
Total: 21.13" tall x 25.75" wide (including brackets)
Core: 15.88" tall x 22.5" wide x 2.75" thick
Inlet: 1.5" driver side
Outlet: 1.75" passenger side
Tanks: 3.13" thick
Tubes: 0.63" thick


How do I get the water pump to crank pulley ratio?
 
I never have been a big fan of those shrouds that are like a flat wall. I tried one and it didn't seem to help. And definitely when you're traveling at speed it almost seems to hurt. And also it seems like no matter what you'll have to have the fans on all of the time...
 
MC2374 Radiator Dimensions:
Total:
21.13" tall x 25.75" wide (including brackets)
Core: 15.88" tall x 22.5" wide x 2.75" thick
Inlet: 1.5" driver side
Outlet: 1.75" passenger side
Tanks: 3.13" thick
Tubes: 0.63" thick


How do I get the water pump to crank pulley ratio?
How many rows of .63 tubes?
With the cap off look inside the neck and count the rows.
I take the diameter or circumference of water pump and crank pullies. Divide the largest number into the smaller, that will roughly give you the percentage of overdrive which is really what you are looking for.
 
How many rows of .63 tubes?
With the cap off look inside the neck and count the rows.
I take the diameter or circumference of water pump and crank pullies. Divide the largest number into the smaller, that will roughly give you the percentage of overdrive which is really what you are looking for.
Its a 4 row champion radiator.
 
Its a 4 row champion radiator.
Well there is part of your problem
4 row rads are old tech the 4th row will actually transfer heat back into the 3 row making them both pretty much useless.
Modern trend is to use 1 or 1 1/4 inch tubes for only 2 rows
I have had several 2 row they cool very well
Look at Griffin radiators they are made in the USA and work very well
Are you sure your lower rad hose is not collapsing at cruzing rpm?
 
Well there is part of your problem
4 row rads are old tech the 4th row will actually transfer heat back into the 3 row making them both pretty much useless.
Modern trend is to use 1 or 1 1/4 inch tubes for only 2 rows
I have had several 2 row they cool very well
Look at Griffin radiators they are made in the USA and work very well
Are you sure your lower rad hose is not collapsing at cruzing rpm?

I have a cheap Champion 4 row in my 416. Drive in 90+ So Cal weather. At track in California desert, highway cruise at 3400+ rpm... no issues.

I suspect there’s more issues than a radiator going on.
 
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